From 805d9eaf5eab0edc3567d9e19e74a3f9168e764a Mon Sep 17 00:00:00 2001
From: Denton Liu <liu.denton@gmail.com>
Date: Sat, 21 Mar 2020 05:21:20 -0400
Subject: [PATCH 01/22] Makefile: ASCII-sort += lists

There are many += lists in the Makefile and, over time, they have gotten
slightly out of ASCII order. Sort all += lists to bring them back in
order.

ASCII sorting was chosen over strict alphabetical order even though, if
we omit file prefixes, the lists aren't sorted in strictly alphabetical
order (e.g. archive.o comes after archive-zip.o instead of before
archive-tar.o). This is intentional because the purpose of maintaining
the sorted list is to ensure line insertions are deterministic. By using
ASCII ordering, it is more easily mechanically reproducible in the
future, such as by using :sort in Vim.

This patch is best viewed with `--color-moved`.

Signed-off-by: Denton Liu <liu.denton@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
---
 Makefile | 77 ++++++++++++++++++++++++++++----------------------------
 1 file changed, 39 insertions(+), 38 deletions(-)

diff --git a/Makefile b/Makefile
index 9804a0758b..f709fc3f77 100644
--- a/Makefile
+++ b/Makefile
@@ -604,12 +604,12 @@ unexport CDPATH
 SCRIPT_SH += git-bisect.sh
 SCRIPT_SH += git-difftool--helper.sh
 SCRIPT_SH += git-filter-branch.sh
+SCRIPT_SH += git-legacy-stash.sh
 SCRIPT_SH += git-merge-octopus.sh
 SCRIPT_SH += git-merge-one-file.sh
 SCRIPT_SH += git-merge-resolve.sh
 SCRIPT_SH += git-mergetool.sh
 SCRIPT_SH += git-quiltimport.sh
-SCRIPT_SH += git-legacy-stash.sh
 SCRIPT_SH += git-request-pull.sh
 SCRIPT_SH += git-submodule.sh
 SCRIPT_SH += git-web--browse.sh
@@ -617,8 +617,8 @@ SCRIPT_SH += git-web--browse.sh
 SCRIPT_LIB += git-mergetool--lib
 SCRIPT_LIB += git-parse-remote
 SCRIPT_LIB += git-rebase--preserve-merges
-SCRIPT_LIB += git-sh-setup
 SCRIPT_LIB += git-sh-i18n
+SCRIPT_LIB += git-sh-setup
 
 SCRIPT_PERL += git-add--interactive.perl
 SCRIPT_PERL += git-archimport.perl
@@ -686,9 +686,9 @@ PROGRAM_OBJS += daemon.o
 PROGRAM_OBJS += fast-import.o
 PROGRAM_OBJS += http-backend.o
 PROGRAM_OBJS += imap-send.o
+PROGRAM_OBJS += remote-testsvn.o
 PROGRAM_OBJS += sh-i18n--envsubst.o
 PROGRAM_OBJS += shell.o
-PROGRAM_OBJS += remote-testsvn.o
 
 # Binary suffix, set to .exe for Windows builds
 X =
@@ -709,9 +709,9 @@ TEST_BUILTINS_OBJS += test-dump-untracked-cache.o
 TEST_BUILTINS_OBJS += test-example-decorate.o
 TEST_BUILTINS_OBJS += test-genrandom.o
 TEST_BUILTINS_OBJS += test-genzeros.o
+TEST_BUILTINS_OBJS += test-hash-speed.o
 TEST_BUILTINS_OBJS += test-hash.o
 TEST_BUILTINS_OBJS += test-hashmap.o
-TEST_BUILTINS_OBJS += test-hash-speed.o
 TEST_BUILTINS_OBJS += test-index-version.o
 TEST_BUILTINS_OBJS += test-json-writer.o
 TEST_BUILTINS_OBJS += test-lazy-init-name-hash.o
@@ -737,8 +737,8 @@ TEST_BUILTINS_OBJS += test-revision-walking.o
 TEST_BUILTINS_OBJS += test-run-command.o
 TEST_BUILTINS_OBJS += test-scrap-cache-tree.o
 TEST_BUILTINS_OBJS += test-serve-v2.o
-TEST_BUILTINS_OBJS += test-sha1.o
 TEST_BUILTINS_OBJS += test-sha1-array.o
+TEST_BUILTINS_OBJS += test-sha1.o
 TEST_BUILTINS_OBJS += test-sha256.o
 TEST_BUILTINS_OBJS += test-sigchain.o
 TEST_BUILTINS_OBJS += test-strcmp-offset.o
@@ -748,10 +748,10 @@ TEST_BUILTINS_OBJS += test-submodule-nested-repo-config.o
 TEST_BUILTINS_OBJS += test-subprocess.o
 TEST_BUILTINS_OBJS += test-trace2.o
 TEST_BUILTINS_OBJS += test-urlmatch-normalization.o
-TEST_BUILTINS_OBJS += test-xml-encode.o
 TEST_BUILTINS_OBJS += test-wildmatch.o
 TEST_BUILTINS_OBJS += test-windows-named-pipe.o
 TEST_BUILTINS_OBJS += test-write-cache.o
+TEST_BUILTINS_OBJS += test-xml-encode.o
 
 # Do not add more tests here unless they have extra dependencies. Add
 # them in TEST_BUILTINS_OBJS above.
@@ -788,10 +788,10 @@ OTHER_PROGRAMS = git$X
 
 # what test wrappers are needed and 'install' will install, in bindir
 BINDIR_PROGRAMS_NEED_X += git
-BINDIR_PROGRAMS_NEED_X += git-upload-pack
 BINDIR_PROGRAMS_NEED_X += git-receive-pack
-BINDIR_PROGRAMS_NEED_X += git-upload-archive
 BINDIR_PROGRAMS_NEED_X += git-shell
+BINDIR_PROGRAMS_NEED_X += git-upload-archive
+BINDIR_PROGRAMS_NEED_X += git-upload-pack
 
 BINDIR_PROGRAMS_NO_X += git-cvsserver
 
@@ -831,9 +831,9 @@ LIB_OBJS += advice.o
 LIB_OBJS += alias.o
 LIB_OBJS += alloc.o
 LIB_OBJS += apply.o
-LIB_OBJS += archive.o
 LIB_OBJS += archive-tar.o
 LIB_OBJS += archive-zip.o
+LIB_OBJS += archive.o
 LIB_OBJS += argv-array.o
 LIB_OBJS += attr.o
 LIB_OBJS += base85.o
@@ -849,9 +849,9 @@ LIB_OBJS += checkout.o
 LIB_OBJS += color.o
 LIB_OBJS += column.o
 LIB_OBJS += combine-diff.o
-LIB_OBJS += commit.o
 LIB_OBJS += commit-graph.o
 LIB_OBJS += commit-reach.o
+LIB_OBJS += commit.o
 LIB_OBJS += compat/obstack.o
 LIB_OBJS += compat/terminal.o
 LIB_OBJS += config.o
@@ -865,17 +865,17 @@ LIB_OBJS += ctype.o
 LIB_OBJS += date.o
 LIB_OBJS += decorate.o
 LIB_OBJS += delta-islands.o
+LIB_OBJS += diff-delta.o
+LIB_OBJS += diff-lib.o
+LIB_OBJS += diff-no-index.o
+LIB_OBJS += diff.o
 LIB_OBJS += diffcore-break.o
 LIB_OBJS += diffcore-delta.o
 LIB_OBJS += diffcore-order.o
 LIB_OBJS += diffcore-pickaxe.o
 LIB_OBJS += diffcore-rename.o
-LIB_OBJS += diff-delta.o
-LIB_OBJS += diff-lib.o
-LIB_OBJS += diff-no-index.o
-LIB_OBJS += diff.o
-LIB_OBJS += dir.o
 LIB_OBJS += dir-iterator.o
+LIB_OBJS += dir.o
 LIB_OBJS += editor.o
 LIB_OBJS += entry.o
 LIB_OBJS += environment.o
@@ -893,7 +893,6 @@ LIB_OBJS += gpg-interface.o
 LIB_OBJS += graph.o
 LIB_OBJS += grep.o
 LIB_OBJS += hashmap.o
-LIB_OBJS += linear-assignment.o
 LIB_OBJS += help.o
 LIB_OBJS += hex.o
 LIB_OBJS += ident.o
@@ -903,9 +902,10 @@ LIB_OBJS += kwset.o
 LIB_OBJS += levenshtein.o
 LIB_OBJS += line-log.o
 LIB_OBJS += line-range.o
-LIB_OBJS += list-objects.o
-LIB_OBJS += list-objects-filter.o
+LIB_OBJS += linear-assignment.o
 LIB_OBJS += list-objects-filter-options.o
+LIB_OBJS += list-objects-filter.o
+LIB_OBJS += list-objects.o
 LIB_OBJS += ll-merge.o
 LIB_OBJS += lockfile.o
 LIB_OBJS += log-tree.o
@@ -914,31 +914,31 @@ LIB_OBJS += mailinfo.o
 LIB_OBJS += mailmap.o
 LIB_OBJS += match-trees.o
 LIB_OBJS += mem-pool.o
-LIB_OBJS += merge.o
 LIB_OBJS += merge-blobs.o
 LIB_OBJS += merge-recursive.o
+LIB_OBJS += merge.o
 LIB_OBJS += mergesort.o
 LIB_OBJS += midx.o
 LIB_OBJS += name-hash.o
 LIB_OBJS += negotiator/default.o
 LIB_OBJS += negotiator/skipping.o
-LIB_OBJS += notes.o
 LIB_OBJS += notes-cache.o
 LIB_OBJS += notes-merge.o
 LIB_OBJS += notes-utils.o
+LIB_OBJS += notes.o
 LIB_OBJS += object.o
 LIB_OBJS += oidmap.o
 LIB_OBJS += oidset.o
-LIB_OBJS += packfile.o
-LIB_OBJS += pack-bitmap.o
 LIB_OBJS += pack-bitmap-write.o
+LIB_OBJS += pack-bitmap.o
 LIB_OBJS += pack-check.o
 LIB_OBJS += pack-objects.o
 LIB_OBJS += pack-revindex.o
 LIB_OBJS += pack-write.o
+LIB_OBJS += packfile.o
 LIB_OBJS += pager.o
-LIB_OBJS += parse-options.o
 LIB_OBJS += parse-options-cb.o
+LIB_OBJS += parse-options.o
 LIB_OBJS += patch-delta.o
 LIB_OBJS += patch-ids.o
 LIB_OBJS += path.o
@@ -955,8 +955,9 @@ LIB_OBJS += quote.o
 LIB_OBJS += range-diff.o
 LIB_OBJS += reachable.o
 LIB_OBJS += read-cache.o
-LIB_OBJS += rebase.o
 LIB_OBJS += rebase-interactive.o
+LIB_OBJS += rebase.o
+LIB_OBJS += ref-filter.o
 LIB_OBJS += reflog-walk.o
 LIB_OBJS += refs.o
 LIB_OBJS += refs/files-backend.o
@@ -964,7 +965,6 @@ LIB_OBJS += refs/iterator.o
 LIB_OBJS += refs/packed-backend.o
 LIB_OBJS += refs/ref-cache.o
 LIB_OBJS += refspec.o
-LIB_OBJS += ref-filter.o
 LIB_OBJS += remote.o
 LIB_OBJS += replace-object.o
 LIB_OBJS += repo-settings.o
@@ -979,8 +979,8 @@ LIB_OBJS += serve.o
 LIB_OBJS += server-info.o
 LIB_OBJS += setup.o
 LIB_OBJS += sha1-array.o
-LIB_OBJS += sha1-lookup.o
 LIB_OBJS += sha1-file.o
+LIB_OBJS += sha1-lookup.o
 LIB_OBJS += sha1-name.o
 LIB_OBJS += shallow.o
 LIB_OBJS += sideband.o
@@ -990,9 +990,9 @@ LIB_OBJS += stable-qsort.o
 LIB_OBJS += strbuf.o
 LIB_OBJS += streaming.o
 LIB_OBJS += string-list.o
-LIB_OBJS += submodule.o
-LIB_OBJS += submodule-config.o
 LIB_OBJS += sub-process.o
+LIB_OBJS += submodule-config.o
+LIB_OBJS += submodule.o
 LIB_OBJS += symlinks.o
 LIB_OBJS += tag.o
 LIB_OBJS += tempfile.o
@@ -1011,11 +1011,11 @@ LIB_OBJS += trace2/tr2_tgt_normal.o
 LIB_OBJS += trace2/tr2_tgt_perf.o
 LIB_OBJS += trace2/tr2_tls.o
 LIB_OBJS += trailer.o
-LIB_OBJS += transport.o
 LIB_OBJS += transport-helper.o
+LIB_OBJS += transport.o
 LIB_OBJS += tree-diff.o
-LIB_OBJS += tree.o
 LIB_OBJS += tree-walk.o
+LIB_OBJS += tree.o
 LIB_OBJS += unpack-trees.o
 LIB_OBJS += upload-pack.o
 LIB_OBJS += url.o
@@ -1055,9 +1055,9 @@ BUILTIN_OBJS += builtin/checkout.o
 BUILTIN_OBJS += builtin/clean.o
 BUILTIN_OBJS += builtin/clone.o
 BUILTIN_OBJS += builtin/column.o
+BUILTIN_OBJS += builtin/commit-graph.o
 BUILTIN_OBJS += builtin/commit-tree.o
 BUILTIN_OBJS += builtin/commit.o
-BUILTIN_OBJS += builtin/commit-graph.o
 BUILTIN_OBJS += builtin/config.o
 BUILTIN_OBJS += builtin/count-objects.o
 BUILTIN_OBJS += builtin/credential.o
@@ -1088,13 +1088,13 @@ BUILTIN_OBJS += builtin/ls-remote.o
 BUILTIN_OBJS += builtin/ls-tree.o
 BUILTIN_OBJS += builtin/mailinfo.o
 BUILTIN_OBJS += builtin/mailsplit.o
-BUILTIN_OBJS += builtin/merge.o
 BUILTIN_OBJS += builtin/merge-base.o
 BUILTIN_OBJS += builtin/merge-file.o
 BUILTIN_OBJS += builtin/merge-index.o
 BUILTIN_OBJS += builtin/merge-ours.o
 BUILTIN_OBJS += builtin/merge-recursive.o
 BUILTIN_OBJS += builtin/merge-tree.o
+BUILTIN_OBJS += builtin/merge.o
 BUILTIN_OBJS += builtin/mktag.o
 BUILTIN_OBJS += builtin/mktree.o
 BUILTIN_OBJS += builtin/multi-pack-index.o
@@ -1114,9 +1114,9 @@ BUILTIN_OBJS += builtin/read-tree.o
 BUILTIN_OBJS += builtin/rebase.o
 BUILTIN_OBJS += builtin/receive-pack.o
 BUILTIN_OBJS += builtin/reflog.o
-BUILTIN_OBJS += builtin/remote.o
 BUILTIN_OBJS += builtin/remote-ext.o
 BUILTIN_OBJS += builtin/remote-fd.o
+BUILTIN_OBJS += builtin/remote.o
 BUILTIN_OBJS += builtin/repack.o
 BUILTIN_OBJS += builtin/replace.o
 BUILTIN_OBJS += builtin/rerere.o
@@ -2335,16 +2335,16 @@ reconfigure config.mak.autogen: config.status
 endif
 
 XDIFF_OBJS += xdiff/xdiffi.o
-XDIFF_OBJS += xdiff/xprepare.o
-XDIFF_OBJS += xdiff/xutils.o
 XDIFF_OBJS += xdiff/xemit.o
+XDIFF_OBJS += xdiff/xhistogram.o
 XDIFF_OBJS += xdiff/xmerge.o
 XDIFF_OBJS += xdiff/xpatience.o
-XDIFF_OBJS += xdiff/xhistogram.o
+XDIFF_OBJS += xdiff/xprepare.o
+XDIFF_OBJS += xdiff/xutils.o
 
+VCSSVN_OBJS += vcs-svn/fast_export.o
 VCSSVN_OBJS += vcs-svn/line_buffer.o
 VCSSVN_OBJS += vcs-svn/sliding_window.o
-VCSSVN_OBJS += vcs-svn/fast_export.o
 VCSSVN_OBJS += vcs-svn/svndiff.o
 VCSSVN_OBJS += vcs-svn/svndump.o
 
@@ -3152,9 +3152,10 @@ endif
 #
 ALL_COMMANDS = $(ALL_PROGRAMS) $(SCRIPT_LIB) $(BUILT_INS)
 ALL_COMMANDS += git
+ALL_COMMANDS += git-citool
+ALL_COMMANDS += git-gui
 ALL_COMMANDS += gitk
 ALL_COMMANDS += gitweb
-ALL_COMMANDS += git-gui git-citool
 
 .PHONY: check-docs
 check-docs::

From fd6852cab219149e800d352f3939631377b41575 Mon Sep 17 00:00:00 2001
From: Denton Liu <liu.denton@gmail.com>
Date: Sat, 21 Mar 2020 05:21:21 -0400
Subject: [PATCH 02/22] t7600: use test_write_lines()

In t7600, we were rewriting `printf '%s\n' ...` to create files from
parameters, one per line. However, we already have a function that wraps
this for us: test_write_lines(). Rewrite these instances to use that
function instead of open coding it.

Signed-off-by: Denton Liu <liu.denton@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
---
 t/t7600-merge.sh | 22 +++++++++++-----------
 1 file changed, 11 insertions(+), 11 deletions(-)

diff --git a/t/t7600-merge.sh b/t/t7600-merge.sh
index 132608879a..4fa0ef8e3b 100755
--- a/t/t7600-merge.sh
+++ b/t/t7600-merge.sh
@@ -29,15 +29,15 @@ Testing basic merge operations/option parsing.
 . ./test-lib.sh
 . "$TEST_DIRECTORY"/lib-gpg.sh
 
-printf '%s\n' 1 2 3 4 5 6 7 8 9 >file
-printf '%s\n' '1 X' 2 3 4 5 6 7 8 9 >file.1
-printf '%s\n' 1 2 3 4 '5 X' 6 7 8 9 >file.5
-printf '%s\n' 1 2 3 4 5 6 7 8 '9 X' >file.9
-printf '%s\n' 1 2 3 4 5 6 7 8 '9 Y' >file.9y
-printf '%s\n' '1 X' 2 3 4 5 6 7 8 9 >result.1
-printf '%s\n' '1 X' 2 3 4 '5 X' 6 7 8 9 >result.1-5
-printf '%s\n' '1 X' 2 3 4 '5 X' 6 7 8 '9 X' >result.1-5-9
-printf '%s\n' 1 2 3 4 5 6 7 8 '9 Z' >result.9z
+test_write_lines 1 2 3 4 5 6 7 8 9 >file
+test_write_lines '1 X' 2 3 4 5 6 7 8 9 >file.1
+test_write_lines 1 2 3 4 '5 X' 6 7 8 9 >file.5
+test_write_lines 1 2 3 4 5 6 7 8 '9 X' >file.9
+test_write_lines 1 2 3 4 5 6 7 8 '9 Y' >file.9y
+test_write_lines '1 X' 2 3 4 5 6 7 8 9 >result.1
+test_write_lines '1 X' 2 3 4 '5 X' 6 7 8 9 >result.1-5
+test_write_lines '1 X' 2 3 4 '5 X' 6 7 8 '9 X' >result.1-5-9
+test_write_lines 1 2 3 4 5 6 7 8 '9 Z' >result.9z
 
 create_merge_msgs () {
 	echo "Merge tag 'c2'" >msg.1-5 &&
@@ -81,7 +81,7 @@ verify_head () {
 }
 
 verify_parents () {
-	printf '%s\n' "$@" >parents.expected &&
+	test_write_lines "$@" >parents.expected &&
 	>parents.actual &&
 	i=1 &&
 	while test $i -le $#
@@ -95,7 +95,7 @@ verify_parents () {
 }
 
 verify_mergeheads () {
-	printf '%s\n' "$@" >mergehead.expected &&
+	test_write_lines "$@" >mergehead.expected &&
 	while read sha1 rest
 	do
 		git rev-parse $sha1

From 65c425a2ec815989994716c81a2307ae5b5645bc Mon Sep 17 00:00:00 2001
From: Denton Liu <liu.denton@gmail.com>
Date: Fri, 3 Apr 2020 21:11:16 -0400
Subject: [PATCH 03/22] sequencer: stop leaking buf

In read_populate_opts(), we call read_oneliner() _after_ calling
strbuf_release(). This means that `buf` is leaked at the end of the
function.

Always clean up the strbuf by going to `done_rebase_i` whether or not
we return an error.

Signed-off-by: Denton Liu <liu.denton@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
---
 sequencer.c | 13 +++++++++----
 1 file changed, 9 insertions(+), 4 deletions(-)

diff --git a/sequencer.c b/sequencer.c
index e528225e78..faab0b13e8 100644
--- a/sequencer.c
+++ b/sequencer.c
@@ -2485,6 +2485,7 @@ static int read_populate_opts(struct replay_opts *opts)
 {
 	if (is_rebase_i(opts)) {
 		struct strbuf buf = STRBUF_INIT;
+		int ret = 0;
 
 		if (read_oneliner(&buf, rebase_path_gpg_sign_opt(), 1)) {
 			if (!starts_with(buf.buf, "-S"))
@@ -2525,7 +2526,7 @@ static int read_populate_opts(struct replay_opts *opts)
 			opts->keep_redundant_commits = 1;
 
 		read_strategy_opts(opts, &buf);
-		strbuf_release(&buf);
+		strbuf_reset(&buf);
 
 		if (read_oneliner(&opts->current_fixups,
 				  rebase_path_current_fixups(), 1)) {
@@ -2538,12 +2539,16 @@ static int read_populate_opts(struct replay_opts *opts)
 		}
 
 		if (read_oneliner(&buf, rebase_path_squash_onto(), 0)) {
-			if (get_oid_hex(buf.buf, &opts->squash_onto) < 0)
-				return error(_("unusable squash-onto"));
+			if (get_oid_hex(buf.buf, &opts->squash_onto) < 0) {
+				ret = error(_("unusable squash-onto"));
+				goto done_rebase_i;
+			}
 			opts->have_squash_onto = 1;
 		}
 
-		return 0;
+done_rebase_i:
+		strbuf_release(&buf);
+		return ret;
 	}
 
 	if (!file_exists(git_path_opts_file()))

From 5b2f6d9cd50b1c8909326c7175aef288a9915f33 Mon Sep 17 00:00:00 2001
From: Denton Liu <liu.denton@gmail.com>
Date: Tue, 7 Apr 2020 10:27:51 -0400
Subject: [PATCH 04/22] sequencer: make file exists check more efficient

We currently check whether a file exists and return early before reading
the file. Instead of accessing the file twice, always read the file and
check `errno` to see if the file doesn't exist.

Signed-off-by: Denton Liu <liu.denton@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
---
 sequencer.c | 6 ++----
 1 file changed, 2 insertions(+), 4 deletions(-)

diff --git a/sequencer.c b/sequencer.c
index faab0b13e8..a961cf5a9b 100644
--- a/sequencer.c
+++ b/sequencer.c
@@ -433,11 +433,9 @@ static int read_oneliner(struct strbuf *buf,
 {
 	int orig_len = buf->len;
 
-	if (!file_exists(path))
-		return 0;
-
 	if (strbuf_read_file(buf, path, 0) < 0) {
-		warning_errno(_("could not read '%s'"), path);
+		if (errno != ENOENT && errno != ENOTDIR)
+			warning_errno(_("could not read '%s'"), path);
 		return 0;
 	}
 

From 3442c3d11df16d7cd3867b133a8ec6ddd21a8839 Mon Sep 17 00:00:00 2001
From: Denton Liu <liu.denton@gmail.com>
Date: Tue, 7 Apr 2020 10:27:52 -0400
Subject: [PATCH 05/22] sequencer: make read_oneliner() accept flags

In a future commit, we will need read_oneliner() to accept flags other
than just `skip_if_empty`. Instead of having an argument for each flag,
teach read_oneliner() to accept the bitfield `flags` instead. For now,
only recognize the `READ_ONELINER_SKIP_IF_EMPTY` flag. More flags will
be added in a future commit.

The result of this is that parallel topics which introduce invocations
of read_oneliner() will still be compatible with this new function
signature since, instead of passing 1 or 0 for `skip_if_empty`, they'll
be passing 1 or 0 to `flags`, which gives equivalent behavior.

Mechanically fix up invocations of read_oneliner() with the following
spatch

	@@
	expression a, b;
	@@
	  read_oneliner(a, b,
	- 1
	+ READ_ONELINER_SKIP_IF_EMPTY
	  )

and manually break up long lines in the result.

Signed-off-by: Denton Liu <liu.denton@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
---
 sequencer.c | 21 ++++++++++++++-------
 1 file changed, 14 insertions(+), 7 deletions(-)

diff --git a/sequencer.c b/sequencer.c
index a961cf5a9b..6c4e8743ef 100644
--- a/sequencer.c
+++ b/sequencer.c
@@ -419,6 +419,8 @@ static int write_message(const void *buf, size_t len, const char *filename,
 	return 0;
 }
 
+#define READ_ONELINER_SKIP_IF_EMPTY (1 << 0)
+
 /*
  * Reads a file that was presumably written by a shell script, i.e. with an
  * end-of-line marker that needs to be stripped.
@@ -429,7 +431,7 @@ static int write_message(const void *buf, size_t len, const char *filename,
  * Returns 1 if the file was read, 0 if it could not be read or does not exist.
  */
 static int read_oneliner(struct strbuf *buf,
-	const char *path, int skip_if_empty)
+	const char *path, unsigned flags)
 {
 	int orig_len = buf->len;
 
@@ -445,7 +447,7 @@ static int read_oneliner(struct strbuf *buf,
 		buf->buf[buf->len] = '\0';
 	}
 
-	if (skip_if_empty && buf->len == orig_len)
+	if ((flags & READ_ONELINER_SKIP_IF_EMPTY) && buf->len == orig_len)
 		return 0;
 
 	return 1;
@@ -2485,7 +2487,8 @@ static int read_populate_opts(struct replay_opts *opts)
 		struct strbuf buf = STRBUF_INIT;
 		int ret = 0;
 
-		if (read_oneliner(&buf, rebase_path_gpg_sign_opt(), 1)) {
+		if (read_oneliner(&buf, rebase_path_gpg_sign_opt(),
+				  READ_ONELINER_SKIP_IF_EMPTY)) {
 			if (!starts_with(buf.buf, "-S"))
 				strbuf_reset(&buf);
 			else {
@@ -2495,7 +2498,8 @@ static int read_populate_opts(struct replay_opts *opts)
 			strbuf_reset(&buf);
 		}
 
-		if (read_oneliner(&buf, rebase_path_allow_rerere_autoupdate(), 1)) {
+		if (read_oneliner(&buf, rebase_path_allow_rerere_autoupdate(),
+				  READ_ONELINER_SKIP_IF_EMPTY)) {
 			if (!strcmp(buf.buf, "--rerere-autoupdate"))
 				opts->allow_rerere_auto = RERERE_AUTOUPDATE;
 			else if (!strcmp(buf.buf, "--no-rerere-autoupdate"))
@@ -2527,7 +2531,8 @@ static int read_populate_opts(struct replay_opts *opts)
 		strbuf_reset(&buf);
 
 		if (read_oneliner(&opts->current_fixups,
-				  rebase_path_current_fixups(), 1)) {
+				  rebase_path_current_fixups(),
+				  READ_ONELINER_SKIP_IF_EMPTY)) {
 			const char *p = opts->current_fixups.buf;
 			opts->current_fixup_count = 1;
 			while ((p = strchr(p, '\n'))) {
@@ -3668,7 +3673,8 @@ static int apply_autostash(struct replay_opts *opts)
 	struct child_process child = CHILD_PROCESS_INIT;
 	int ret = 0;
 
-	if (!read_oneliner(&stash_sha1, rebase_path_autostash(), 1)) {
+	if (!read_oneliner(&stash_sha1, rebase_path_autostash(),
+			   READ_ONELINER_SKIP_IF_EMPTY)) {
 		strbuf_release(&stash_sha1);
 		return 0;
 	}
@@ -4292,7 +4298,8 @@ int sequencer_continue(struct repository *r, struct replay_opts *opts)
 		struct strbuf buf = STRBUF_INIT;
 		struct object_id oid;
 
-		if (read_oneliner(&buf, rebase_path_stopped_sha(), 1) &&
+		if (read_oneliner(&buf, rebase_path_stopped_sha(),
+				  READ_ONELINER_SKIP_IF_EMPTY) &&
 		    !get_oid_committish(buf.buf, &oid))
 			record_in_rewritten(&oid, peek_command(&todo_list, 0));
 		strbuf_release(&buf);

From bfa50c2c7f0cb806af6d272a84c16f114e15ceee Mon Sep 17 00:00:00 2001
From: Denton Liu <liu.denton@gmail.com>
Date: Tue, 7 Apr 2020 10:27:53 -0400
Subject: [PATCH 06/22] sequencer: configurably warn on non-existent files

In the future, we plan on externing read_oneliner(). Future users of
read_oneliner() will want the ability to output warnings in the event
that the `path` doesn't exist. Introduce the
`READ_ONELINER_WARN_MISSING` flag which, if active, would issue a
warning when a file doesn't exist by always executing warning_errno()
in the case where strbuf_read_file() fails.

Signed-off-by: Denton Liu <liu.denton@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
---
 sequencer.c | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/sequencer.c b/sequencer.c
index 6c4e8743ef..32cc289da3 100644
--- a/sequencer.c
+++ b/sequencer.c
@@ -420,6 +420,7 @@ static int write_message(const void *buf, size_t len, const char *filename,
 }
 
 #define READ_ONELINER_SKIP_IF_EMPTY (1 << 0)
+#define READ_ONELINER_WARN_MISSING (1 << 1)
 
 /*
  * Reads a file that was presumably written by a shell script, i.e. with an
@@ -436,7 +437,8 @@ static int read_oneliner(struct strbuf *buf,
 	int orig_len = buf->len;
 
 	if (strbuf_read_file(buf, path, 0) < 0) {
-		if (errno != ENOENT && errno != ENOTDIR)
+		if ((flags & READ_ONELINER_WARN_MISSING) ||
+		    (errno != ENOENT && errno != ENOTDIR))
 			warning_errno(_("could not read '%s'"), path);
 		return 0;
 	}

From c20de8bec6ba759c5e17ad8b8fd7105e8228e313 Mon Sep 17 00:00:00 2001
From: Denton Liu <liu.denton@gmail.com>
Date: Tue, 7 Apr 2020 10:27:54 -0400
Subject: [PATCH 07/22] sequencer: make read_oneliner() extern

The function read_oneliner() is a generally useful util function.
Instead of hiding it as a static function within sequencer.c, extern it
so that it can be reused by others.

This patch is best viewed with --color-moved.

Signed-off-by: Denton Liu <liu.denton@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
---
 sequencer.c | 14 +-------------
 sequencer.h | 14 ++++++++++++++
 2 files changed, 15 insertions(+), 13 deletions(-)

diff --git a/sequencer.c b/sequencer.c
index 32cc289da3..0d98ddc33c 100644
--- a/sequencer.c
+++ b/sequencer.c
@@ -419,19 +419,7 @@ static int write_message(const void *buf, size_t len, const char *filename,
 	return 0;
 }
 
-#define READ_ONELINER_SKIP_IF_EMPTY (1 << 0)
-#define READ_ONELINER_WARN_MISSING (1 << 1)
-
-/*
- * Reads a file that was presumably written by a shell script, i.e. with an
- * end-of-line marker that needs to be stripped.
- *
- * Note that only the last end-of-line marker is stripped, consistent with the
- * behavior of "$(cat path)" in a shell script.
- *
- * Returns 1 if the file was read, 0 if it could not be read or does not exist.
- */
-static int read_oneliner(struct strbuf *buf,
+int read_oneliner(struct strbuf *buf,
 	const char *path, unsigned flags)
 {
 	int orig_len = buf->len;
diff --git a/sequencer.h b/sequencer.h
index 718a07426d..ab43717fd6 100644
--- a/sequencer.h
+++ b/sequencer.h
@@ -198,6 +198,20 @@ void print_commit_summary(struct repository *repo,
 			  const struct object_id *oid,
 			  unsigned int flags);
 
+#define READ_ONELINER_SKIP_IF_EMPTY (1 << 0)
+#define READ_ONELINER_WARN_MISSING (1 << 1)
+
+/*
+ * Reads a file that was presumably written by a shell script, i.e. with an
+ * end-of-line marker that needs to be stripped.
+ *
+ * Note that only the last end-of-line marker is stripped, consistent with the
+ * behavior of "$(cat path)" in a shell script.
+ *
+ * Returns 1 if the file was read, 0 if it could not be read or does not exist.
+ */
+int read_oneliner(struct strbuf *buf,
+	const char *path, unsigned flags);
 int read_author_script(const char *path, char **name, char **email, char **date,
 		       int allow_missing);
 void parse_strategy_opts(struct replay_opts *opts, char *raw_opts);

From efcf6cf0492c4a78d968c6246698d9aafae61578 Mon Sep 17 00:00:00 2001
From: Denton Liu <liu.denton@gmail.com>
Date: Tue, 7 Apr 2020 10:27:55 -0400
Subject: [PATCH 08/22] rebase: use read_oneliner()

Since in sequencer.c, read_one() basically duplicates the functionality
of read_oneliner(), reduce code duplication by replacing read_one() with
read_oneliner().

This was done with the following Coccinelle script

	@@
	expression a, b;
	@@
	- read_one(a, b)
	+ !read_oneliner(b, a, READ_ONELINER_WARN_MISSING)

and long lines were manually broken up.

Signed-off-by: Denton Liu <liu.denton@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
---
 builtin/rebase.c | 37 +++++++++++++++++--------------------
 1 file changed, 17 insertions(+), 20 deletions(-)

diff --git a/builtin/rebase.c b/builtin/rebase.c
index bff53d5d16..57dbfd2a4f 100644
--- a/builtin/rebase.c
+++ b/builtin/rebase.c
@@ -586,15 +586,6 @@ static const char *state_dir_path(const char *filename, struct rebase_options *o
 	return path.buf;
 }
 
-/* Read one file, then strip line endings */
-static int read_one(const char *path, struct strbuf *buf)
-{
-	if (strbuf_read_file(buf, path, 0) < 0)
-		return error_errno(_("could not read '%s'"), path);
-	strbuf_trim_trailing_newline(buf);
-	return 0;
-}
-
 /* Initialize the rebase options from the state directory. */
 static int read_basic_state(struct rebase_options *opts)
 {
@@ -602,8 +593,10 @@ static int read_basic_state(struct rebase_options *opts)
 	struct strbuf buf = STRBUF_INIT;
 	struct object_id oid;
 
-	if (read_one(state_dir_path("head-name", opts), &head_name) ||
-	    read_one(state_dir_path("onto", opts), &buf))
+	if (!read_oneliner(&head_name, state_dir_path("head-name", opts),
+			   READ_ONELINER_WARN_MISSING) ||
+	    !read_oneliner(&buf, state_dir_path("onto", opts),
+			   READ_ONELINER_WARN_MISSING))
 		return -1;
 	opts->head_name = starts_with(head_name.buf, "refs/") ?
 		xstrdup(head_name.buf) : NULL;
@@ -619,9 +612,11 @@ static int read_basic_state(struct rebase_options *opts)
 	 */
 	strbuf_reset(&buf);
 	if (file_exists(state_dir_path("orig-head", opts))) {
-		if (read_one(state_dir_path("orig-head", opts), &buf))
+		if (!read_oneliner(&buf, state_dir_path("orig-head", opts),
+				   READ_ONELINER_WARN_MISSING))
 			return -1;
-	} else if (read_one(state_dir_path("head", opts), &buf))
+	} else if (!read_oneliner(&buf, state_dir_path("head", opts),
+				  READ_ONELINER_WARN_MISSING))
 		return -1;
 	if (get_oid(buf.buf, &opts->orig_head))
 		return error(_("invalid orig-head: '%s'"), buf.buf);
@@ -641,8 +636,8 @@ static int read_basic_state(struct rebase_options *opts)
 
 	if (file_exists(state_dir_path("allow_rerere_autoupdate", opts))) {
 		strbuf_reset(&buf);
-		if (read_one(state_dir_path("allow_rerere_autoupdate", opts),
-			    &buf))
+		if (!read_oneliner(&buf, state_dir_path("allow_rerere_autoupdate", opts),
+				   READ_ONELINER_WARN_MISSING))
 			return -1;
 		if (!strcmp(buf.buf, "--rerere-autoupdate"))
 			opts->allow_rerere_autoupdate = RERERE_AUTOUPDATE;
@@ -655,8 +650,8 @@ static int read_basic_state(struct rebase_options *opts)
 
 	if (file_exists(state_dir_path("gpg_sign_opt", opts))) {
 		strbuf_reset(&buf);
-		if (read_one(state_dir_path("gpg_sign_opt", opts),
-			    &buf))
+		if (!read_oneliner(&buf, state_dir_path("gpg_sign_opt", opts),
+				   READ_ONELINER_WARN_MISSING))
 			return -1;
 		free(opts->gpg_sign_opt);
 		opts->gpg_sign_opt = xstrdup(buf.buf);
@@ -664,7 +659,8 @@ static int read_basic_state(struct rebase_options *opts)
 
 	if (file_exists(state_dir_path("strategy", opts))) {
 		strbuf_reset(&buf);
-		if (read_one(state_dir_path("strategy", opts), &buf))
+		if (!read_oneliner(&buf, state_dir_path("strategy", opts),
+				   READ_ONELINER_WARN_MISSING))
 			return -1;
 		free(opts->strategy);
 		opts->strategy = xstrdup(buf.buf);
@@ -672,7 +668,8 @@ static int read_basic_state(struct rebase_options *opts)
 
 	if (file_exists(state_dir_path("strategy_opts", opts))) {
 		strbuf_reset(&buf);
-		if (read_one(state_dir_path("strategy_opts", opts), &buf))
+		if (!read_oneliner(&buf, state_dir_path("strategy_opts", opts),
+				   READ_ONELINER_WARN_MISSING))
 			return -1;
 		free(opts->strategy_opts);
 		opts->strategy_opts = xstrdup(buf.buf);
@@ -724,7 +721,7 @@ static int apply_autostash(struct rebase_options *opts)
 	if (!file_exists(path))
 		return 0;
 
-	if (read_one(path, &autostash))
+	if (!read_oneliner(&autostash, path, READ_ONELINER_WARN_MISSING))
 		return error(_("Could not read '%s'"), path);
 	/* Ensure that the hash is not mistaken for a number */
 	strbuf_addstr(&autostash, "^0");

From be1bb600da13523dd2d63ae93432d7f3b16ffb74 Mon Sep 17 00:00:00 2001
From: Denton Liu <liu.denton@gmail.com>
Date: Tue, 7 Apr 2020 10:27:56 -0400
Subject: [PATCH 09/22] sequencer: make apply_autostash() accept a path

In order to make apply_autostash() more generic for future extraction, make
it accept a `path` argument so that the location from where to read the
reference to the autostash commit can be customized. Remove the `opts`
argument since it was unused before anyway.

Signed-off-by: Denton Liu <liu.denton@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
---
 sequencer.c | 14 +++++++-------
 1 file changed, 7 insertions(+), 7 deletions(-)

diff --git a/sequencer.c b/sequencer.c
index 0d98ddc33c..4917c70a86 100644
--- a/sequencer.c
+++ b/sequencer.c
@@ -3657,13 +3657,13 @@ static enum todo_command peek_command(struct todo_list *todo_list, int offset)
 	return -1;
 }
 
-static int apply_autostash(struct replay_opts *opts)
+static int apply_autostash(const char *path)
 {
 	struct strbuf stash_sha1 = STRBUF_INIT;
 	struct child_process child = CHILD_PROCESS_INIT;
 	int ret = 0;
 
-	if (!read_oneliner(&stash_sha1, rebase_path_autostash(),
+	if (!read_oneliner(&stash_sha1, path,
 			   READ_ONELINER_SKIP_IF_EMPTY)) {
 		strbuf_release(&stash_sha1);
 		return 0;
@@ -3756,7 +3756,7 @@ static int checkout_onto(struct repository *r, struct replay_opts *opts,
 		return error(_("%s: not a valid OID"), orig_head);
 
 	if (run_git_checkout(r, opts, oid_to_hex(onto), action)) {
-		apply_autostash(opts);
+		apply_autostash(rebase_path_autostash());
 		sequencer_remove_state(opts);
 		return error(_("could not detach HEAD"));
 	}
@@ -4070,7 +4070,7 @@ static int pick_commits(struct repository *r,
 				run_command(&hook);
 			}
 		}
-		apply_autostash(opts);
+		apply_autostash(rebase_path_autostash());
 
 		if (!opts->quiet) {
 			if (!opts->verbose)
@@ -5079,7 +5079,7 @@ int complete_action(struct repository *r, struct replay_opts *opts, unsigned fla
 		todo_list_add_exec_commands(todo_list, commands);
 
 	if (count_commands(todo_list) == 0) {
-		apply_autostash(opts);
+		apply_autostash(rebase_path_autostash());
 		sequencer_remove_state(opts);
 
 		return error(_("nothing to do"));
@@ -5090,12 +5090,12 @@ int complete_action(struct repository *r, struct replay_opts *opts, unsigned fla
 	if (res == -1)
 		return -1;
 	else if (res == -2) {
-		apply_autostash(opts);
+		apply_autostash(rebase_path_autostash());
 		sequencer_remove_state(opts);
 
 		return -1;
 	} else if (res == -3) {
-		apply_autostash(opts);
+		apply_autostash(rebase_path_autostash());
 		sequencer_remove_state(opts);
 		todo_list_release(&new_todo);
 

From facca7f06e7256bf15675657f59ef6f6c883aec3 Mon Sep 17 00:00:00 2001
From: Denton Liu <liu.denton@gmail.com>
Date: Tue, 7 Apr 2020 10:27:57 -0400
Subject: [PATCH 10/22] sequencer: rename stash_sha1 to stash_oid

The preferred terminology is to refer to object identifiers as "OIDs".
Rename the `stash_sha1` variable to `stash_oid` in order to conform to
this.

Signed-off-by: Denton Liu <liu.denton@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
---
 sequencer.c | 16 ++++++++--------
 1 file changed, 8 insertions(+), 8 deletions(-)

diff --git a/sequencer.c b/sequencer.c
index 4917c70a86..4a6812e90e 100644
--- a/sequencer.c
+++ b/sequencer.c
@@ -3659,23 +3659,23 @@ static enum todo_command peek_command(struct todo_list *todo_list, int offset)
 
 static int apply_autostash(const char *path)
 {
-	struct strbuf stash_sha1 = STRBUF_INIT;
+	struct strbuf stash_oid = STRBUF_INIT;
 	struct child_process child = CHILD_PROCESS_INIT;
 	int ret = 0;
 
-	if (!read_oneliner(&stash_sha1, path,
+	if (!read_oneliner(&stash_oid, path,
 			   READ_ONELINER_SKIP_IF_EMPTY)) {
-		strbuf_release(&stash_sha1);
+		strbuf_release(&stash_oid);
 		return 0;
 	}
-	strbuf_trim(&stash_sha1);
+	strbuf_trim(&stash_oid);
 
 	child.git_cmd = 1;
 	child.no_stdout = 1;
 	child.no_stderr = 1;
 	argv_array_push(&child.args, "stash");
 	argv_array_push(&child.args, "apply");
-	argv_array_push(&child.args, stash_sha1.buf);
+	argv_array_push(&child.args, stash_oid.buf);
 	if (!run_command(&child))
 		fprintf(stderr, _("Applied autostash.\n"));
 	else {
@@ -3687,9 +3687,9 @@ static int apply_autostash(const char *path)
 		argv_array_push(&store.args, "-m");
 		argv_array_push(&store.args, "autostash");
 		argv_array_push(&store.args, "-q");
-		argv_array_push(&store.args, stash_sha1.buf);
+		argv_array_push(&store.args, stash_oid.buf);
 		if (run_command(&store))
-			ret = error(_("cannot store %s"), stash_sha1.buf);
+			ret = error(_("cannot store %s"), stash_oid.buf);
 		else
 			fprintf(stderr,
 				_("Applying autostash resulted in conflicts.\n"
@@ -3698,7 +3698,7 @@ static int apply_autostash(const char *path)
 				  " \"git stash drop\" at any time.\n"));
 	}
 
-	strbuf_release(&stash_sha1);
+	strbuf_release(&stash_oid);
 	return ret;
 }
 

From 86ed00aff4b86eed6ecc606e9d5f7828a1dca353 Mon Sep 17 00:00:00 2001
From: Denton Liu <liu.denton@gmail.com>
Date: Tue, 7 Apr 2020 10:27:58 -0400
Subject: [PATCH 11/22] rebase: use apply_autostash() from sequencer.c

The apply_autostash() function in builtin/rebase.c is similar enough to
the apply_autostash() function in sequencer.c that they are almost
interchangeable, except for the type of arg they accept. Make the
sequencer.c version extern and use it in rebase.

The rebase version was introduced in 6defce2b02 (builtin rebase: support
`--autostash` option, 2018-09-04) as part of the shell to C conversion.
It opted to duplicate the function because, at the time, there was
another in-progress project converting interactive rebase from shell to
C as well and they did not want to clash with them by refactoring
sequencer.c version of apply_autostash(). Since both efforts are long
done, we can freely combine them together now.

Signed-off-by: Denton Liu <liu.denton@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
---
 builtin/rebase.c | 49 ++----------------------------------------------
 sequencer.c      |  2 +-
 sequencer.h      |  2 ++
 3 files changed, 5 insertions(+), 48 deletions(-)

diff --git a/builtin/rebase.c b/builtin/rebase.c
index 57dbfd2a4f..cb0bdfc3e4 100644
--- a/builtin/rebase.c
+++ b/builtin/rebase.c
@@ -712,51 +712,6 @@ static int rebase_write_basic_state(struct rebase_options *opts)
 	return 0;
 }
 
-static int apply_autostash(struct rebase_options *opts)
-{
-	const char *path = state_dir_path("autostash", opts);
-	struct strbuf autostash = STRBUF_INIT;
-	struct child_process stash_apply = CHILD_PROCESS_INIT;
-
-	if (!file_exists(path))
-		return 0;
-
-	if (!read_oneliner(&autostash, path, READ_ONELINER_WARN_MISSING))
-		return error(_("Could not read '%s'"), path);
-	/* Ensure that the hash is not mistaken for a number */
-	strbuf_addstr(&autostash, "^0");
-	argv_array_pushl(&stash_apply.args,
-			 "stash", "apply", autostash.buf, NULL);
-	stash_apply.git_cmd = 1;
-	stash_apply.no_stderr = stash_apply.no_stdout =
-		stash_apply.no_stdin = 1;
-	if (!run_command(&stash_apply))
-		printf(_("Applied autostash.\n"));
-	else {
-		struct argv_array args = ARGV_ARRAY_INIT;
-		int res = 0;
-
-		argv_array_pushl(&args,
-				 "stash", "store", "-m", "autostash", "-q",
-				 autostash.buf, NULL);
-		if (run_command_v_opt(args.argv, RUN_GIT_CMD))
-			res = error(_("Cannot store %s"), autostash.buf);
-		argv_array_clear(&args);
-		strbuf_release(&autostash);
-		if (res)
-			return res;
-
-		fprintf(stderr,
-			_("Applying autostash resulted in conflicts.\n"
-			  "Your changes are safe in the stash.\n"
-			  "You can run \"git stash pop\" or \"git stash drop\" "
-			  "at any time.\n"));
-	}
-
-	strbuf_release(&autostash);
-	return 0;
-}
-
 static int finish_rebase(struct rebase_options *opts)
 {
 	struct strbuf dir = STRBUF_INIT;
@@ -764,7 +719,7 @@ static int finish_rebase(struct rebase_options *opts)
 	int ret = 0;
 
 	delete_ref(NULL, "REBASE_HEAD", NULL, REF_NO_DEREF);
-	apply_autostash(opts);
+	apply_autostash(state_dir_path("autostash", opts));
 	close_object_store(the_repository->objects);
 	/*
 	 * We ignore errors in 'gc --auto', since the
@@ -1209,7 +1164,7 @@ static int run_specific_rebase(struct rebase_options *opts, enum action action)
 	} else if (status == 2) {
 		struct strbuf dir = STRBUF_INIT;
 
-		apply_autostash(opts);
+		apply_autostash(state_dir_path("autostash", opts));
 		strbuf_addstr(&dir, opts->state_dir);
 		remove_dir_recursively(&dir, 0);
 		strbuf_release(&dir);
diff --git a/sequencer.c b/sequencer.c
index 4a6812e90e..f5bb1cc1fb 100644
--- a/sequencer.c
+++ b/sequencer.c
@@ -3657,7 +3657,7 @@ static enum todo_command peek_command(struct todo_list *todo_list, int offset)
 	return -1;
 }
 
-static int apply_autostash(const char *path)
+int apply_autostash(const char *path)
 {
 	struct strbuf stash_oid = STRBUF_INIT;
 	struct child_process child = CHILD_PROCESS_INIT;
diff --git a/sequencer.h b/sequencer.h
index ab43717fd6..ab686146d1 100644
--- a/sequencer.h
+++ b/sequencer.h
@@ -191,6 +191,8 @@ void commit_post_rewrite(struct repository *r,
 			 const struct commit *current_head,
 			 const struct object_id *new_head);
 
+int apply_autostash(const char *path);
+
 #define SUMMARY_INITIAL_COMMIT   (1 << 0)
 #define SUMMARY_SHOW_AUTHOR_DATE (1 << 1)
 void print_commit_summary(struct repository *repo,

From f213f069fb57996505f9d6c9dd0f4a3ef53e87e4 Mon Sep 17 00:00:00 2001
From: Denton Liu <liu.denton@gmail.com>
Date: Tue, 7 Apr 2020 10:27:59 -0400
Subject: [PATCH 12/22] rebase: generify reset_head()

In the future, we plan on lib-ifying reset_head() so we need it to
be more generic. Make it more generic by making it accept a
`struct repository` argument instead of implicitly using the non-repo
functions. Also, make it accept a `const char *default_reflog_action`
argument so that the default action of "rebase" isn't hardcoded in.

Signed-off-by: Denton Liu <liu.denton@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
---
 builtin/rebase.c | 64 ++++++++++++++++++++++++++++--------------------
 1 file changed, 37 insertions(+), 27 deletions(-)

diff --git a/builtin/rebase.c b/builtin/rebase.c
index cb0bdfc3e4..5532286142 100644
--- a/builtin/rebase.c
+++ b/builtin/rebase.c
@@ -28,6 +28,8 @@
 #include "sequencer.h"
 #include "rebase-interactive.h"
 
+#define DEFAULT_REFLOG_ACTION "rebase"
+
 static char const * const builtin_rebase_usage[] = {
 	N_("git rebase [-i] [options] [--exec <cmd>] "
 		"[--onto <newbase> | --keep-base] [<upstream> [<branch>]]"),
@@ -772,9 +774,10 @@ static void add_var(struct strbuf *buf, const char *name, const char *value)
 #define RESET_HEAD_REFS_ONLY (1<<3)
 #define RESET_ORIG_HEAD (1<<4)
 
-static int reset_head(struct object_id *oid, const char *action,
+static int reset_head(struct repository *r, struct object_id *oid, const char *action,
 		      const char *switch_to_branch, unsigned flags,
-		      const char *reflog_orig_head, const char *reflog_head)
+		      const char *reflog_orig_head, const char *reflog_head,
+		      const char *default_reflog_action)
 {
 	unsigned detach_head = flags & RESET_HEAD_DETACH;
 	unsigned reset_hard = flags & RESET_HEAD_HARD;
@@ -796,7 +799,7 @@ static int reset_head(struct object_id *oid, const char *action,
 	if (switch_to_branch && !starts_with(switch_to_branch, "refs/"))
 		BUG("Not a fully qualified branch: '%s'", switch_to_branch);
 
-	if (!refs_only && hold_locked_index(&lock, LOCK_REPORT_ON_ERROR) < 0) {
+	if (!refs_only && repo_hold_locked_index(r, &lock, LOCK_REPORT_ON_ERROR) < 0) {
 		ret = -1;
 		goto leave_reset_head;
 	}
@@ -815,26 +818,26 @@ static int reset_head(struct object_id *oid, const char *action,
 	memset(&unpack_tree_opts, 0, sizeof(unpack_tree_opts));
 	setup_unpack_trees_porcelain(&unpack_tree_opts, action);
 	unpack_tree_opts.head_idx = 1;
-	unpack_tree_opts.src_index = the_repository->index;
-	unpack_tree_opts.dst_index = the_repository->index;
+	unpack_tree_opts.src_index = r->index;
+	unpack_tree_opts.dst_index = r->index;
 	unpack_tree_opts.fn = reset_hard ? oneway_merge : twoway_merge;
 	unpack_tree_opts.update = 1;
 	unpack_tree_opts.merge = 1;
 	if (!detach_head)
 		unpack_tree_opts.reset = 1;
 
-	if (repo_read_index_unmerged(the_repository) < 0) {
+	if (repo_read_index_unmerged(r) < 0) {
 		ret = error(_("could not read index"));
 		goto leave_reset_head;
 	}
 
-	if (!reset_hard && !fill_tree_descriptor(the_repository, &desc[nr++], &head_oid)) {
+	if (!reset_hard && !fill_tree_descriptor(r, &desc[nr++], &head_oid)) {
 		ret = error(_("failed to find tree of %s"),
 			    oid_to_hex(&head_oid));
 		goto leave_reset_head;
 	}
 
-	if (!fill_tree_descriptor(the_repository, &desc[nr++], oid)) {
+	if (!fill_tree_descriptor(r, &desc[nr++], oid)) {
 		ret = error(_("failed to find tree of %s"), oid_to_hex(oid));
 		goto leave_reset_head;
 	}
@@ -845,16 +848,16 @@ static int reset_head(struct object_id *oid, const char *action,
 	}
 
 	tree = parse_tree_indirect(oid);
-	prime_cache_tree(the_repository, the_repository->index, tree);
+	prime_cache_tree(r, r->index, tree);
 
-	if (write_locked_index(the_repository->index, &lock, COMMIT_LOCK) < 0) {
+	if (write_locked_index(r->index, &lock, COMMIT_LOCK) < 0) {
 		ret = error(_("could not write index"));
 		goto leave_reset_head;
 	}
 
 reset_head_refs:
 	reflog_action = getenv(GIT_REFLOG_ACTION_ENVIRONMENT);
-	strbuf_addf(&msg, "%s: ", reflog_action ? reflog_action : "rebase");
+	strbuf_addf(&msg, "%s: ", reflog_action ? reflog_action : default_reflog_action);
 	prefix_len = msg.len;
 
 	if (update_orig_head) {
@@ -916,8 +919,10 @@ static int move_to_original_branch(struct rebase_options *opts)
 		    opts->head_name, oid_to_hex(&opts->onto->object.oid));
 	strbuf_addf(&head_reflog, "rebase finished: returning to %s",
 		    opts->head_name);
-	ret = reset_head(NULL, "", opts->head_name, RESET_HEAD_REFS_ONLY,
-			 orig_head_reflog.buf, head_reflog.buf);
+	ret = reset_head(the_repository, NULL, "", opts->head_name,
+			 RESET_HEAD_REFS_ONLY,
+			 orig_head_reflog.buf, head_reflog.buf,
+			 DEFAULT_REFLOG_ACTION);
 
 	strbuf_release(&orig_head_reflog);
 	strbuf_release(&head_reflog);
@@ -1005,8 +1010,9 @@ static int run_am(struct rebase_options *opts)
 		free(rebased_patches);
 		argv_array_clear(&am.args);
 
-		reset_head(&opts->orig_head, "checkout", opts->head_name, 0,
-			   "HEAD", NULL);
+		reset_head(the_repository, &opts->orig_head, "checkout",
+			   opts->head_name, 0,
+			   "HEAD", NULL, DEFAULT_REFLOG_ACTION);
 		error(_("\ngit encountered an error while preparing the "
 			"patches to replay\n"
 			"these revisions:\n"
@@ -1661,8 +1667,8 @@ int cmd_rebase(int argc, const char **argv, const char *prefix)
 		rerere_clear(the_repository, &merge_rr);
 		string_list_clear(&merge_rr, 1);
 
-		if (reset_head(NULL, "reset", NULL, RESET_HEAD_HARD,
-			       NULL, NULL) < 0)
+		if (reset_head(the_repository, NULL, "reset", NULL, RESET_HEAD_HARD,
+			       NULL, NULL, DEFAULT_REFLOG_ACTION) < 0)
 			die(_("could not discard worktree changes"));
 		remove_branch_state(the_repository, 0);
 		if (read_basic_state(&options))
@@ -1679,9 +1685,9 @@ int cmd_rebase(int argc, const char **argv, const char *prefix)
 
 		if (read_basic_state(&options))
 			exit(1);
-		if (reset_head(&options.orig_head, "reset",
+		if (reset_head(the_repository, &options.orig_head, "reset",
 			       options.head_name, RESET_HEAD_HARD,
-			       NULL, NULL) < 0)
+			       NULL, NULL, DEFAULT_REFLOG_ACTION) < 0)
 			die(_("could not move back to %s"),
 			    oid_to_hex(&options.orig_head));
 		remove_branch_state(the_repository, 0);
@@ -2073,8 +2079,9 @@ int cmd_rebase(int argc, const char **argv, const char *prefix)
 				    options.state_dir);
 			write_file(autostash, "%s", oid_to_hex(&oid));
 			printf(_("Created autostash: %s\n"), buf.buf);
-			if (reset_head(NULL, "reset --hard",
-				       NULL, RESET_HEAD_HARD, NULL, NULL) < 0)
+			if (reset_head(the_repository, NULL, "reset --hard",
+				       NULL, RESET_HEAD_HARD, NULL, NULL,
+				       DEFAULT_REFLOG_ACTION) < 0)
 				die(_("could not reset --hard"));
 
 			if (discard_index(the_repository->index) < 0 ||
@@ -2114,10 +2121,12 @@ int cmd_rebase(int argc, const char **argv, const char *prefix)
 				strbuf_addf(&buf, "%s: checkout %s",
 					    getenv(GIT_REFLOG_ACTION_ENVIRONMENT),
 					    options.switch_to);
-				if (reset_head(&options.orig_head, "checkout",
+				if (reset_head(the_repository,
+					       &options.orig_head, "checkout",
 					       options.head_name,
 					       RESET_HEAD_RUN_POST_CHECKOUT_HOOK,
-					       NULL, buf.buf) < 0) {
+					       NULL, buf.buf,
+					       DEFAULT_REFLOG_ACTION) < 0) {
 					ret = !!error(_("could not switch to "
 							"%s"),
 						      options.switch_to);
@@ -2189,10 +2198,10 @@ int cmd_rebase(int argc, const char **argv, const char *prefix)
 
 	strbuf_addf(&msg, "%s: checkout %s",
 		    getenv(GIT_REFLOG_ACTION_ENVIRONMENT), options.onto_name);
-	if (reset_head(&options.onto->object.oid, "checkout", NULL,
+	if (reset_head(the_repository, &options.onto->object.oid, "checkout", NULL,
 		       RESET_HEAD_DETACH | RESET_ORIG_HEAD |
 		       RESET_HEAD_RUN_POST_CHECKOUT_HOOK,
-		       NULL, msg.buf))
+		       NULL, msg.buf, DEFAULT_REFLOG_ACTION))
 		die(_("Could not detach HEAD"));
 	strbuf_release(&msg);
 
@@ -2207,8 +2216,9 @@ int cmd_rebase(int argc, const char **argv, const char *prefix)
 		strbuf_addf(&msg, "rebase finished: %s onto %s",
 			options.head_name ? options.head_name : "detached HEAD",
 			oid_to_hex(&options.onto->object.oid));
-		reset_head(NULL, "Fast-forwarded", options.head_name,
-			   RESET_HEAD_REFS_ONLY, "HEAD", msg.buf);
+		reset_head(the_repository, NULL, "Fast-forwarded", options.head_name,
+			   RESET_HEAD_REFS_ONLY, "HEAD", msg.buf,
+			   DEFAULT_REFLOG_ACTION);
 		strbuf_release(&msg);
 		ret = !!finish_rebase(&options);
 		goto cleanup;

From b309a9710899dab2f76455526f573a90fad5d13c Mon Sep 17 00:00:00 2001
From: Denton Liu <liu.denton@gmail.com>
Date: Tue, 7 Apr 2020 10:28:00 -0400
Subject: [PATCH 13/22] reset: extract reset_head() from rebase

Continue the process of lib-ifying the autostash code. In a future
commit, this will be used to implement `--autostash` in other builtins.

This patch is best viewed with `--color-moved`.

Signed-off-by: Denton Liu <liu.denton@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
---
 Makefile         |   1 +
 builtin/rebase.c | 139 +---------------------------------------------
 reset.c          | 140 +++++++++++++++++++++++++++++++++++++++++++++++
 reset.h          |  20 +++++++
 4 files changed, 162 insertions(+), 138 deletions(-)
 create mode 100644 reset.c
 create mode 100644 reset.h

diff --git a/Makefile b/Makefile
index f709fc3f77..338fb55b73 100644
--- a/Makefile
+++ b/Makefile
@@ -970,6 +970,7 @@ LIB_OBJS += replace-object.o
 LIB_OBJS += repo-settings.o
 LIB_OBJS += repository.o
 LIB_OBJS += rerere.o
+LIB_OBJS += reset.o
 LIB_OBJS += resolve-undo.o
 LIB_OBJS += revision.o
 LIB_OBJS += run-command.o
diff --git a/builtin/rebase.c b/builtin/rebase.c
index 5532286142..48ef36bd10 100644
--- a/builtin/rebase.c
+++ b/builtin/rebase.c
@@ -27,6 +27,7 @@
 #include "branch.h"
 #include "sequencer.h"
 #include "rebase-interactive.h"
+#include "reset.h"
 
 #define DEFAULT_REFLOG_ACTION "rebase"
 
@@ -766,144 +767,6 @@ static void add_var(struct strbuf *buf, const char *name, const char *value)
 	}
 }
 
-#define GIT_REFLOG_ACTION_ENVIRONMENT "GIT_REFLOG_ACTION"
-
-#define RESET_HEAD_DETACH (1<<0)
-#define RESET_HEAD_HARD (1<<1)
-#define RESET_HEAD_RUN_POST_CHECKOUT_HOOK (1<<2)
-#define RESET_HEAD_REFS_ONLY (1<<3)
-#define RESET_ORIG_HEAD (1<<4)
-
-static int reset_head(struct repository *r, struct object_id *oid, const char *action,
-		      const char *switch_to_branch, unsigned flags,
-		      const char *reflog_orig_head, const char *reflog_head,
-		      const char *default_reflog_action)
-{
-	unsigned detach_head = flags & RESET_HEAD_DETACH;
-	unsigned reset_hard = flags & RESET_HEAD_HARD;
-	unsigned run_hook = flags & RESET_HEAD_RUN_POST_CHECKOUT_HOOK;
-	unsigned refs_only = flags & RESET_HEAD_REFS_ONLY;
-	unsigned update_orig_head = flags & RESET_ORIG_HEAD;
-	struct object_id head_oid;
-	struct tree_desc desc[2] = { { NULL }, { NULL } };
-	struct lock_file lock = LOCK_INIT;
-	struct unpack_trees_options unpack_tree_opts;
-	struct tree *tree;
-	const char *reflog_action;
-	struct strbuf msg = STRBUF_INIT;
-	size_t prefix_len;
-	struct object_id *orig = NULL, oid_orig,
-		*old_orig = NULL, oid_old_orig;
-	int ret = 0, nr = 0;
-
-	if (switch_to_branch && !starts_with(switch_to_branch, "refs/"))
-		BUG("Not a fully qualified branch: '%s'", switch_to_branch);
-
-	if (!refs_only && repo_hold_locked_index(r, &lock, LOCK_REPORT_ON_ERROR) < 0) {
-		ret = -1;
-		goto leave_reset_head;
-	}
-
-	if ((!oid || !reset_hard) && get_oid("HEAD", &head_oid)) {
-		ret = error(_("could not determine HEAD revision"));
-		goto leave_reset_head;
-	}
-
-	if (!oid)
-		oid = &head_oid;
-
-	if (refs_only)
-		goto reset_head_refs;
-
-	memset(&unpack_tree_opts, 0, sizeof(unpack_tree_opts));
-	setup_unpack_trees_porcelain(&unpack_tree_opts, action);
-	unpack_tree_opts.head_idx = 1;
-	unpack_tree_opts.src_index = r->index;
-	unpack_tree_opts.dst_index = r->index;
-	unpack_tree_opts.fn = reset_hard ? oneway_merge : twoway_merge;
-	unpack_tree_opts.update = 1;
-	unpack_tree_opts.merge = 1;
-	if (!detach_head)
-		unpack_tree_opts.reset = 1;
-
-	if (repo_read_index_unmerged(r) < 0) {
-		ret = error(_("could not read index"));
-		goto leave_reset_head;
-	}
-
-	if (!reset_hard && !fill_tree_descriptor(r, &desc[nr++], &head_oid)) {
-		ret = error(_("failed to find tree of %s"),
-			    oid_to_hex(&head_oid));
-		goto leave_reset_head;
-	}
-
-	if (!fill_tree_descriptor(r, &desc[nr++], oid)) {
-		ret = error(_("failed to find tree of %s"), oid_to_hex(oid));
-		goto leave_reset_head;
-	}
-
-	if (unpack_trees(nr, desc, &unpack_tree_opts)) {
-		ret = -1;
-		goto leave_reset_head;
-	}
-
-	tree = parse_tree_indirect(oid);
-	prime_cache_tree(r, r->index, tree);
-
-	if (write_locked_index(r->index, &lock, COMMIT_LOCK) < 0) {
-		ret = error(_("could not write index"));
-		goto leave_reset_head;
-	}
-
-reset_head_refs:
-	reflog_action = getenv(GIT_REFLOG_ACTION_ENVIRONMENT);
-	strbuf_addf(&msg, "%s: ", reflog_action ? reflog_action : default_reflog_action);
-	prefix_len = msg.len;
-
-	if (update_orig_head) {
-		if (!get_oid("ORIG_HEAD", &oid_old_orig))
-			old_orig = &oid_old_orig;
-		if (!get_oid("HEAD", &oid_orig)) {
-			orig = &oid_orig;
-			if (!reflog_orig_head) {
-				strbuf_addstr(&msg, "updating ORIG_HEAD");
-				reflog_orig_head = msg.buf;
-			}
-			update_ref(reflog_orig_head, "ORIG_HEAD", orig,
-				   old_orig, 0, UPDATE_REFS_MSG_ON_ERR);
-		} else if (old_orig)
-			delete_ref(NULL, "ORIG_HEAD", old_orig, 0);
-	}
-
-	if (!reflog_head) {
-		strbuf_setlen(&msg, prefix_len);
-		strbuf_addstr(&msg, "updating HEAD");
-		reflog_head = msg.buf;
-	}
-	if (!switch_to_branch)
-		ret = update_ref(reflog_head, "HEAD", oid, orig,
-				 detach_head ? REF_NO_DEREF : 0,
-				 UPDATE_REFS_MSG_ON_ERR);
-	else {
-		ret = update_ref(reflog_head, switch_to_branch, oid,
-				 NULL, 0, UPDATE_REFS_MSG_ON_ERR);
-		if (!ret)
-			ret = create_symref("HEAD", switch_to_branch,
-					    reflog_head);
-	}
-	if (run_hook)
-		run_hook_le(NULL, "post-checkout",
-			    oid_to_hex(orig ? orig : &null_oid),
-			    oid_to_hex(oid), "1", NULL);
-
-leave_reset_head:
-	strbuf_release(&msg);
-	rollback_lock_file(&lock);
-	while (nr)
-		free((void *)desc[--nr].buffer);
-	return ret;
-}
-
 static int move_to_original_branch(struct rebase_options *opts)
 {
 	struct strbuf orig_head_reflog = STRBUF_INIT, head_reflog = STRBUF_INIT;
diff --git a/reset.c b/reset.c
new file mode 100644
index 0000000000..79b683bffa
--- /dev/null
+++ b/reset.c
@@ -0,0 +1,140 @@
+#include "git-compat-util.h"
+#include "cache-tree.h"
+#include "lockfile.h"
+#include "refs.h"
+#include "reset.h"
+#include "run-command.h"
+#include "tree-walk.h"
+#include "tree.h"
+#include "unpack-trees.h"
+
+int reset_head(struct repository *r, struct object_id *oid, const char *action,
+	       const char *switch_to_branch, unsigned flags,
+	       const char *reflog_orig_head, const char *reflog_head,
+	       const char *default_reflog_action)
+{
+	unsigned detach_head = flags & RESET_HEAD_DETACH;
+	unsigned reset_hard = flags & RESET_HEAD_HARD;
+	unsigned run_hook = flags & RESET_HEAD_RUN_POST_CHECKOUT_HOOK;
+	unsigned refs_only = flags & RESET_HEAD_REFS_ONLY;
+	unsigned update_orig_head = flags & RESET_ORIG_HEAD;
+	struct object_id head_oid;
+	struct tree_desc desc[2] = { { NULL }, { NULL } };
+	struct lock_file lock = LOCK_INIT;
+	struct unpack_trees_options unpack_tree_opts;
+	struct tree *tree;
+	const char *reflog_action;
+	struct strbuf msg = STRBUF_INIT;
+	size_t prefix_len;
+	struct object_id *orig = NULL, oid_orig,
+		*old_orig = NULL, oid_old_orig;
+	int ret = 0, nr = 0;
+
+	if (switch_to_branch && !starts_with(switch_to_branch, "refs/"))
+		BUG("Not a fully qualified branch: '%s'", switch_to_branch);
+
+	if (!refs_only && repo_hold_locked_index(r, &lock, LOCK_REPORT_ON_ERROR) < 0) {
+		ret = -1;
+		goto leave_reset_head;
+	}
+
+	if ((!oid || !reset_hard) && get_oid("HEAD", &head_oid)) {
+		ret = error(_("could not determine HEAD revision"));
+		goto leave_reset_head;
+	}
+
+	if (!oid)
+		oid = &head_oid;
+
+	if (refs_only)
+		goto reset_head_refs;
+
+	memset(&unpack_tree_opts, 0, sizeof(unpack_tree_opts));
+	setup_unpack_trees_porcelain(&unpack_tree_opts, action);
+	unpack_tree_opts.head_idx = 1;
+	unpack_tree_opts.src_index = r->index;
+	unpack_tree_opts.dst_index = r->index;
+	unpack_tree_opts.fn = reset_hard ? oneway_merge : twoway_merge;
+	unpack_tree_opts.update = 1;
+	unpack_tree_opts.merge = 1;
+	if (!detach_head)
+		unpack_tree_opts.reset = 1;
+
+	if (repo_read_index_unmerged(r) < 0) {
+		ret = error(_("could not read index"));
+		goto leave_reset_head;
+	}
+
+	if (!reset_hard && !fill_tree_descriptor(r, &desc[nr++], &head_oid)) {
+		ret = error(_("failed to find tree of %s"),
+			    oid_to_hex(&head_oid));
+		goto leave_reset_head;
+	}
+
+	if (!fill_tree_descriptor(r, &desc[nr++], oid)) {
+		ret = error(_("failed to find tree of %s"), oid_to_hex(oid));
+		goto leave_reset_head;
+	}
+
+	if (unpack_trees(nr, desc, &unpack_tree_opts)) {
+		ret = -1;
+		goto leave_reset_head;
+	}
+
+	tree = parse_tree_indirect(oid);
+	prime_cache_tree(r, r->index, tree);
+
+	if (write_locked_index(r->index, &lock, COMMIT_LOCK) < 0) {
+		ret = error(_("could not write index"));
+		goto leave_reset_head;
+	}
+
+reset_head_refs:
+	reflog_action = getenv(GIT_REFLOG_ACTION_ENVIRONMENT);
+	strbuf_addf(&msg, "%s: ", reflog_action ? reflog_action : default_reflog_action);
+	prefix_len = msg.len;
+
+	if (update_orig_head) {
+		if (!get_oid("ORIG_HEAD", &oid_old_orig))
+			old_orig = &oid_old_orig;
+		if (!get_oid("HEAD", &oid_orig)) {
+			orig = &oid_orig;
+			if (!reflog_orig_head) {
+				strbuf_addstr(&msg, "updating ORIG_HEAD");
+				reflog_orig_head = msg.buf;
+			}
+			update_ref(reflog_orig_head, "ORIG_HEAD", orig,
+				   old_orig, 0, UPDATE_REFS_MSG_ON_ERR);
+		} else if (old_orig)
+			delete_ref(NULL, "ORIG_HEAD", old_orig, 0);
+	}
+
+	if (!reflog_head) {
+		strbuf_setlen(&msg, prefix_len);
+		strbuf_addstr(&msg, "updating HEAD");
+		reflog_head = msg.buf;
+	}
+	if (!switch_to_branch)
+		ret = update_ref(reflog_head, "HEAD", oid, orig,
+				 detach_head ? REF_NO_DEREF : 0,
+				 UPDATE_REFS_MSG_ON_ERR);
+	else {
+		ret = update_ref(reflog_head, switch_to_branch, oid,
+				 NULL, 0, UPDATE_REFS_MSG_ON_ERR);
+		if (!ret)
+			ret = create_symref("HEAD", switch_to_branch,
+					    reflog_head);
+	}
+	if (run_hook)
+		run_hook_le(NULL, "post-checkout",
+			    oid_to_hex(orig ? orig : &null_oid),
+			    oid_to_hex(oid), "1", NULL);
+
+leave_reset_head:
+	strbuf_release(&msg);
+	rollback_lock_file(&lock);
+	while (nr)
+		free((void *)desc[--nr].buffer);
+	return ret;
+
+}
diff --git a/reset.h b/reset.h
new file mode 100644
index 0000000000..12f83c78e2
--- /dev/null
+++ b/reset.h
@@ -0,0 +1,20 @@
+#ifndef RESET_H
+#define RESET_H
+
+#include "hash.h"
+#include "repository.h"
+
+#define GIT_REFLOG_ACTION_ENVIRONMENT "GIT_REFLOG_ACTION"
+
+#define RESET_HEAD_DETACH (1<<0)
+#define RESET_HEAD_HARD (1<<1)
+#define RESET_HEAD_RUN_POST_CHECKOUT_HOOK (1<<2)
+#define RESET_HEAD_REFS_ONLY (1<<3)
+#define RESET_ORIG_HEAD (1<<4)
+
+int reset_head(struct repository *r, struct object_id *oid, const char *action,
+	       const char *switch_to_branch, unsigned flags,
+	       const char *reflog_orig_head, const char *reflog_head,
+	       const char *default_reflog_action);
+
+#endif

From 4d4bc157f85316576d9f9bb90657d455fe76e281 Mon Sep 17 00:00:00 2001
From: Denton Liu <liu.denton@gmail.com>
Date: Tue, 7 Apr 2020 10:28:01 -0400
Subject: [PATCH 14/22] rebase: extract create_autostash()

In a future commit, we will lib-ify this code. In preparation for
this, extract the code into the create_autostash() function so that it
can be cleaned up before it is finally lib-ified.

This patch is best viewed with `--color-moved` and
`--color-moved-ws=allow-indentation-change`.

Signed-off-by: Denton Liu <liu.denton@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
---
 builtin/rebase.c | 94 +++++++++++++++++++++++++-----------------------
 1 file changed, 50 insertions(+), 44 deletions(-)

diff --git a/builtin/rebase.c b/builtin/rebase.c
index 48ef36bd10..581ad3af7b 100644
--- a/builtin/rebase.c
+++ b/builtin/rebase.c
@@ -1274,6 +1274,55 @@ static int check_exec_cmd(const char *cmd)
 	return 0;
 }
 
+static void create_autostash(struct rebase_options *options)
+{
+	struct strbuf buf = STRBUF_INIT;
+	struct lock_file lock_file = LOCK_INIT;
+	int fd;
+
+	fd = hold_locked_index(&lock_file, 0);
+	refresh_cache(REFRESH_QUIET);
+	if (0 <= fd)
+		repo_update_index_if_able(the_repository, &lock_file);
+	rollback_lock_file(&lock_file);
+
+	if (has_unstaged_changes(the_repository, 1) ||
+	    has_uncommitted_changes(the_repository, 1)) {
+		const char *autostash =
+			state_dir_path("autostash", options);
+		struct child_process stash = CHILD_PROCESS_INIT;
+		struct object_id oid;
+
+		argv_array_pushl(&stash.args,
+				 "stash", "create", "autostash", NULL);
+		stash.git_cmd = 1;
+		stash.no_stdin = 1;
+		strbuf_reset(&buf);
+		if (capture_command(&stash, &buf, GIT_MAX_HEXSZ))
+			die(_("Cannot autostash"));
+		strbuf_trim_trailing_newline(&buf);
+		if (get_oid(buf.buf, &oid))
+			die(_("Unexpected stash response: '%s'"),
+			    buf.buf);
+		strbuf_reset(&buf);
+		strbuf_add_unique_abbrev(&buf, &oid, DEFAULT_ABBREV);
+
+		if (safe_create_leading_directories_const(autostash))
+			die(_("Could not create directory for '%s'"),
+			    options->state_dir);
+		write_file(autostash, "%s", oid_to_hex(&oid));
+		printf(_("Created autostash: %s\n"), buf.buf);
+		if (reset_head(the_repository, NULL, "reset --hard",
+			       NULL, RESET_HEAD_HARD, NULL, NULL,
+			       DEFAULT_REFLOG_ACTION) < 0)
+			die(_("could not reset --hard"));
+
+		if (discard_index(the_repository->index) < 0 ||
+			repo_read_index(the_repository) < 0)
+			die(_("could not read index"));
+	}
+	strbuf_release(&buf);
+}
 
 int cmd_rebase(int argc, const char **argv, const char *prefix)
 {
@@ -1907,50 +1956,7 @@ int cmd_rebase(int argc, const char **argv, const char *prefix)
 		die(_("could not read index"));
 
 	if (options.autostash) {
-		struct lock_file lock_file = LOCK_INIT;
-		int fd;
-
-		fd = hold_locked_index(&lock_file, 0);
-		refresh_cache(REFRESH_QUIET);
-		if (0 <= fd)
-			repo_update_index_if_able(the_repository, &lock_file);
-		rollback_lock_file(&lock_file);
-
-		if (has_unstaged_changes(the_repository, 1) ||
-		    has_uncommitted_changes(the_repository, 1)) {
-			const char *autostash =
-				state_dir_path("autostash", &options);
-			struct child_process stash = CHILD_PROCESS_INIT;
-			struct object_id oid;
-
-			argv_array_pushl(&stash.args,
-					 "stash", "create", "autostash", NULL);
-			stash.git_cmd = 1;
-			stash.no_stdin = 1;
-			strbuf_reset(&buf);
-			if (capture_command(&stash, &buf, GIT_MAX_HEXSZ))
-				die(_("Cannot autostash"));
-			strbuf_trim_trailing_newline(&buf);
-			if (get_oid(buf.buf, &oid))
-				die(_("Unexpected stash response: '%s'"),
-				    buf.buf);
-			strbuf_reset(&buf);
-			strbuf_add_unique_abbrev(&buf, &oid, DEFAULT_ABBREV);
-
-			if (safe_create_leading_directories_const(autostash))
-				die(_("Could not create directory for '%s'"),
-				    options.state_dir);
-			write_file(autostash, "%s", oid_to_hex(&oid));
-			printf(_("Created autostash: %s\n"), buf.buf);
-			if (reset_head(the_repository, NULL, "reset --hard",
-				       NULL, RESET_HEAD_HARD, NULL, NULL,
-				       DEFAULT_REFLOG_ACTION) < 0)
-				die(_("could not reset --hard"));
-
-			if (discard_index(the_repository->index) < 0 ||
-				repo_read_index(the_repository) < 0)
-				die(_("could not read index"));
-		}
+		create_autostash(&options);
 	}
 
 	if (require_clean_work_tree(the_repository, "rebase",

From 9bb3dea45d69921578b1729c7dc7b12bfbe6f69e Mon Sep 17 00:00:00 2001
From: Denton Liu <liu.denton@gmail.com>
Date: Tue, 7 Apr 2020 10:28:02 -0400
Subject: [PATCH 15/22] rebase: generify create_autostash()

In the future, we plan on lib-ifying create_autostash() so we need it to
be more generic. Make it more generic by making it accept a
`struct repository` argument instead of implicitly using the non-repo
functions and `the_repository`. Also, make it accept a `path` argument
so that we no longer rely have to rely on `struct rebase_options`.
Finally, make it accept a `default_reflog_action` argument so we no
longer have to rely on `DEFAULT_REFLOG_ACTION`.

Signed-off-by: Denton Liu <liu.denton@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
---
 builtin/rebase.c | 32 ++++++++++++++++----------------
 1 file changed, 16 insertions(+), 16 deletions(-)

diff --git a/builtin/rebase.c b/builtin/rebase.c
index 581ad3af7b..ae345c9e57 100644
--- a/builtin/rebase.c
+++ b/builtin/rebase.c
@@ -1274,22 +1274,21 @@ static int check_exec_cmd(const char *cmd)
 	return 0;
 }
 
-static void create_autostash(struct rebase_options *options)
+static void create_autostash(struct repository *r, const char *path,
+			     const char *default_reflog_action)
 {
 	struct strbuf buf = STRBUF_INIT;
 	struct lock_file lock_file = LOCK_INIT;
 	int fd;
 
-	fd = hold_locked_index(&lock_file, 0);
-	refresh_cache(REFRESH_QUIET);
+	fd = repo_hold_locked_index(r, &lock_file, 0);
+	refresh_index(r->index, REFRESH_QUIET, NULL, NULL, NULL);
 	if (0 <= fd)
-		repo_update_index_if_able(the_repository, &lock_file);
+		repo_update_index_if_able(r, &lock_file);
 	rollback_lock_file(&lock_file);
 
-	if (has_unstaged_changes(the_repository, 1) ||
-	    has_uncommitted_changes(the_repository, 1)) {
-		const char *autostash =
-			state_dir_path("autostash", options);
+	if (has_unstaged_changes(r, 1) ||
+	    has_uncommitted_changes(r, 1)) {
 		struct child_process stash = CHILD_PROCESS_INIT;
 		struct object_id oid;
 
@@ -1307,18 +1306,18 @@ static void create_autostash(struct rebase_options *options)
 		strbuf_reset(&buf);
 		strbuf_add_unique_abbrev(&buf, &oid, DEFAULT_ABBREV);
 
-		if (safe_create_leading_directories_const(autostash))
+		if (safe_create_leading_directories_const(path))
 			die(_("Could not create directory for '%s'"),
-			    options->state_dir);
-		write_file(autostash, "%s", oid_to_hex(&oid));
+			    path);
+		write_file(path, "%s", oid_to_hex(&oid));
 		printf(_("Created autostash: %s\n"), buf.buf);
-		if (reset_head(the_repository, NULL, "reset --hard",
+		if (reset_head(r, NULL, "reset --hard",
 			       NULL, RESET_HEAD_HARD, NULL, NULL,
-			       DEFAULT_REFLOG_ACTION) < 0)
+			       default_reflog_action) < 0)
 			die(_("could not reset --hard"));
 
-		if (discard_index(the_repository->index) < 0 ||
-			repo_read_index(the_repository) < 0)
+		if (discard_index(r->index) < 0 ||
+			repo_read_index(r) < 0)
 			die(_("could not read index"));
 	}
 	strbuf_release(&buf);
@@ -1956,7 +1955,8 @@ int cmd_rebase(int argc, const char **argv, const char *prefix)
 		die(_("could not read index"));
 
 	if (options.autostash) {
-		create_autostash(&options);
+		create_autostash(the_repository, state_dir_path("autostash", &options),
+				 DEFAULT_REFLOG_ACTION);
 	}
 
 	if (require_clean_work_tree(the_repository, "rebase",

From 0816f1dff8715e80b5fa0b73b48dd36ef9e1e381 Mon Sep 17 00:00:00 2001
From: Denton Liu <liu.denton@gmail.com>
Date: Tue, 7 Apr 2020 10:28:03 -0400
Subject: [PATCH 16/22] sequencer: extract perform_autostash() from rebase

Lib-ify the autostash code by extracting perform_autostash() from rebase
into sequencer. In a future commit, this will be used to implement
`--autostash` in other builtins.

This patch is best viewed with `--color-moved`.

Signed-off-by: Denton Liu <liu.denton@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
---
 builtin/rebase.c | 49 -----------------------------------------------
 sequencer.c      | 50 ++++++++++++++++++++++++++++++++++++++++++++++++
 sequencer.h      |  2 ++
 3 files changed, 52 insertions(+), 49 deletions(-)

diff --git a/builtin/rebase.c b/builtin/rebase.c
index ae345c9e57..08b89869b3 100644
--- a/builtin/rebase.c
+++ b/builtin/rebase.c
@@ -1274,55 +1274,6 @@ static int check_exec_cmd(const char *cmd)
 	return 0;
 }
 
-static void create_autostash(struct repository *r, const char *path,
-			     const char *default_reflog_action)
-{
-	struct strbuf buf = STRBUF_INIT;
-	struct lock_file lock_file = LOCK_INIT;
-	int fd;
-
-	fd = repo_hold_locked_index(r, &lock_file, 0);
-	refresh_index(r->index, REFRESH_QUIET, NULL, NULL, NULL);
-	if (0 <= fd)
-		repo_update_index_if_able(r, &lock_file);
-	rollback_lock_file(&lock_file);
-
-	if (has_unstaged_changes(r, 1) ||
-	    has_uncommitted_changes(r, 1)) {
-		struct child_process stash = CHILD_PROCESS_INIT;
-		struct object_id oid;
-
-		argv_array_pushl(&stash.args,
-				 "stash", "create", "autostash", NULL);
-		stash.git_cmd = 1;
-		stash.no_stdin = 1;
-		strbuf_reset(&buf);
-		if (capture_command(&stash, &buf, GIT_MAX_HEXSZ))
-			die(_("Cannot autostash"));
-		strbuf_trim_trailing_newline(&buf);
-		if (get_oid(buf.buf, &oid))
-			die(_("Unexpected stash response: '%s'"),
-			    buf.buf);
-		strbuf_reset(&buf);
-		strbuf_add_unique_abbrev(&buf, &oid, DEFAULT_ABBREV);
-
-		if (safe_create_leading_directories_const(path))
-			die(_("Could not create directory for '%s'"),
-			    path);
-		write_file(path, "%s", oid_to_hex(&oid));
-		printf(_("Created autostash: %s\n"), buf.buf);
-		if (reset_head(r, NULL, "reset --hard",
-			       NULL, RESET_HEAD_HARD, NULL, NULL,
-			       default_reflog_action) < 0)
-			die(_("could not reset --hard"));
-
-		if (discard_index(r->index) < 0 ||
-			repo_read_index(r) < 0)
-			die(_("could not read index"));
-	}
-	strbuf_release(&buf);
-}
-
 int cmd_rebase(int argc, const char **argv, const char *prefix)
 {
 	struct rebase_options options = REBASE_OPTIONS_INIT;
diff --git a/sequencer.c b/sequencer.c
index f5bb1cc1fb..e0b8262521 100644
--- a/sequencer.c
+++ b/sequencer.c
@@ -32,6 +32,7 @@
 #include "alias.h"
 #include "commit-reach.h"
 #include "rebase-interactive.h"
+#include "reset.h"
 
 #define GIT_REFLOG_ACTION "GIT_REFLOG_ACTION"
 
@@ -3657,6 +3658,55 @@ static enum todo_command peek_command(struct todo_list *todo_list, int offset)
 	return -1;
 }
 
+void create_autostash(struct repository *r, const char *path,
+		      const char *default_reflog_action)
+{
+	struct strbuf buf = STRBUF_INIT;
+	struct lock_file lock_file = LOCK_INIT;
+	int fd;
+
+	fd = repo_hold_locked_index(r, &lock_file, 0);
+	refresh_index(r->index, REFRESH_QUIET, NULL, NULL, NULL);
+	if (0 <= fd)
+		repo_update_index_if_able(r, &lock_file);
+	rollback_lock_file(&lock_file);
+
+	if (has_unstaged_changes(r, 1) ||
+	    has_uncommitted_changes(r, 1)) {
+		struct child_process stash = CHILD_PROCESS_INIT;
+		struct object_id oid;
+
+		argv_array_pushl(&stash.args,
+				 "stash", "create", "autostash", NULL);
+		stash.git_cmd = 1;
+		stash.no_stdin = 1;
+		strbuf_reset(&buf);
+		if (capture_command(&stash, &buf, GIT_MAX_HEXSZ))
+			die(_("Cannot autostash"));
+		strbuf_trim_trailing_newline(&buf);
+		if (get_oid(buf.buf, &oid))
+			die(_("Unexpected stash response: '%s'"),
+			    buf.buf);
+		strbuf_reset(&buf);
+		strbuf_add_unique_abbrev(&buf, &oid, DEFAULT_ABBREV);
+
+		if (safe_create_leading_directories_const(path))
+			die(_("Could not create directory for '%s'"),
+			    path);
+		write_file(path, "%s", oid_to_hex(&oid));
+		printf(_("Created autostash: %s\n"), buf.buf);
+		if (reset_head(r, NULL, "reset --hard",
+			       NULL, RESET_HEAD_HARD, NULL, NULL,
+			       default_reflog_action) < 0)
+			die(_("could not reset --hard"));
+
+		if (discard_index(r->index) < 0 ||
+			repo_read_index(r) < 0)
+			die(_("could not read index"));
+	}
+	strbuf_release(&buf);
+}
+
 int apply_autostash(const char *path)
 {
 	struct strbuf stash_oid = STRBUF_INIT;
diff --git a/sequencer.h b/sequencer.h
index ab686146d1..9d1fe0ccfb 100644
--- a/sequencer.h
+++ b/sequencer.h
@@ -191,6 +191,8 @@ void commit_post_rewrite(struct repository *r,
 			 const struct commit *current_head,
 			 const struct object_id *new_head);
 
+void create_autostash(struct repository *r, const char *path,
+		      const char *default_reflog_action);
 int apply_autostash(const char *path);
 
 #define SUMMARY_INITIAL_COMMIT   (1 << 0)

From 0dd562e0f7c0bb9ca64f1a02265ff5d1be86df34 Mon Sep 17 00:00:00 2001
From: Denton Liu <liu.denton@gmail.com>
Date: Tue, 7 Apr 2020 10:28:04 -0400
Subject: [PATCH 17/22] sequencer: unlink autostash in apply_autostash()

Explicitly remove autostash file in apply_autostash() once it has been
applied successfully.

This is currently a no-op because the only users of this function will unlink
the state (including the autostash file) after this function runs.
However, in the future, we will introduce a user of the function that
does not explicitly remove the state so we do it here.

Signed-off-by: Denton Liu <liu.denton@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
---
 sequencer.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/sequencer.c b/sequencer.c
index e0b8262521..645bc47ce3 100644
--- a/sequencer.c
+++ b/sequencer.c
@@ -3748,6 +3748,7 @@ int apply_autostash(const char *path)
 				  " \"git stash drop\" at any time.\n"));
 	}
 
+	unlink(path);
 	strbuf_release(&stash_oid);
 	return ret;
 }

From 12b6e1367af429628dbaeaa0c7518cacc620d786 Mon Sep 17 00:00:00 2001
From: Denton Liu <liu.denton@gmail.com>
Date: Tue, 7 Apr 2020 10:28:05 -0400
Subject: [PATCH 18/22] sequencer: implement save_autostash()

Extract common functionality of apply_autostash() into
apply_save_autostash() and use it to implement save_autostash(). This
function will be used in a future commit.

The difference between save_autostash() and apply_autostash() is that
the former does not try to apply the stash. It skips that step and
just stores the created entry in the stash reflog.

This is useful in the case where we abort an operation when an autostash
is present but we don't want to dirty the worktree with the application
of the stash. For example, in a future commit, we will implement
`git merge --autostash`. Since merges can be aborted using
`git reset --hard`, we'd make use of save_autostash() to save the
autostash entry instead of applying it to the worktree thus keeping the
worktree undirtied.

Signed-off-by: Denton Liu <liu.denton@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
---
 sequencer.c | 37 +++++++++++++++++++++++++++----------
 sequencer.h |  1 +
 2 files changed, 28 insertions(+), 10 deletions(-)

diff --git a/sequencer.c b/sequencer.c
index 645bc47ce3..084ea4117e 100644
--- a/sequencer.c
+++ b/sequencer.c
@@ -3707,7 +3707,7 @@ void create_autostash(struct repository *r, const char *path,
 	strbuf_release(&buf);
 }
 
-int apply_autostash(const char *path)
+static int apply_save_autostash(const char *path, int attempt_apply)
 {
 	struct strbuf stash_oid = STRBUF_INIT;
 	struct child_process child = CHILD_PROCESS_INIT;
@@ -3720,13 +3720,17 @@ int apply_autostash(const char *path)
 	}
 	strbuf_trim(&stash_oid);
 
-	child.git_cmd = 1;
-	child.no_stdout = 1;
-	child.no_stderr = 1;
-	argv_array_push(&child.args, "stash");
-	argv_array_push(&child.args, "apply");
-	argv_array_push(&child.args, stash_oid.buf);
-	if (!run_command(&child))
+	if (attempt_apply) {
+		child.git_cmd = 1;
+		child.no_stdout = 1;
+		child.no_stderr = 1;
+		argv_array_push(&child.args, "stash");
+		argv_array_push(&child.args, "apply");
+		argv_array_push(&child.args, stash_oid.buf);
+		ret = run_command(&child);
+	}
+
+	if (attempt_apply && !ret)
 		fprintf(stderr, _("Applied autostash.\n"));
 	else {
 		struct child_process store = CHILD_PROCESS_INIT;
@@ -3742,10 +3746,13 @@ int apply_autostash(const char *path)
 			ret = error(_("cannot store %s"), stash_oid.buf);
 		else
 			fprintf(stderr,
-				_("Applying autostash resulted in conflicts.\n"
+				_("%s\n"
 				  "Your changes are safe in the stash.\n"
 				  "You can run \"git stash pop\" or"
-				  " \"git stash drop\" at any time.\n"));
+				  " \"git stash drop\" at any time.\n"),
+				attempt_apply ?
+				_("Applying autostash resulted in conflicts.") :
+				_("Autostash exists; creating a new stash entry."));
 	}
 
 	unlink(path);
@@ -3753,6 +3760,16 @@ int apply_autostash(const char *path)
 	return ret;
 }
 
+int save_autostash(const char *path)
+{
+	return apply_save_autostash(path, 0);
+}
+
+int apply_autostash(const char *path)
+{
+	return apply_save_autostash(path, 1);
+}
+
 static const char *reflog_message(struct replay_opts *opts,
 	const char *sub_action, const char *fmt, ...)
 {
diff --git a/sequencer.h b/sequencer.h
index 9d1fe0ccfb..306d4cecfb 100644
--- a/sequencer.h
+++ b/sequencer.h
@@ -193,6 +193,7 @@ void commit_post_rewrite(struct repository *r,
 
 void create_autostash(struct repository *r, const char *path,
 		      const char *default_reflog_action);
+int save_autostash(const char *path);
 int apply_autostash(const char *path);
 
 #define SUMMARY_INITIAL_COMMIT   (1 << 0)

From 804fe3155761e73c3dcc4e162ddb3ff560f16cd7 Mon Sep 17 00:00:00 2001
From: Denton Liu <liu.denton@gmail.com>
Date: Tue, 7 Apr 2020 10:28:06 -0400
Subject: [PATCH 19/22] sequencer: implement apply_autostash_oid()

Split apply_save_autostash() into apply_autostash_oid() and
apply_save_autostash() where the former operates on an OID string and
the latter reads the OID from a file before passing it into
apply_save_autostash_oid().

This function is required for a future commmit which will rely on being
able to apply an autostash whose OID is stored as a string.

Signed-off-by: Denton Liu <liu.denton@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
---
 sequencer.c | 38 ++++++++++++++++++++++++++------------
 sequencer.h |  1 +
 2 files changed, 27 insertions(+), 12 deletions(-)

diff --git a/sequencer.c b/sequencer.c
index 084ea4117e..f1eba4cb1f 100644
--- a/sequencer.c
+++ b/sequencer.c
@@ -3707,26 +3707,18 @@ void create_autostash(struct repository *r, const char *path,
 	strbuf_release(&buf);
 }
 
-static int apply_save_autostash(const char *path, int attempt_apply)
+static int apply_save_autostash_oid(const char *stash_oid, int attempt_apply)
 {
-	struct strbuf stash_oid = STRBUF_INIT;
 	struct child_process child = CHILD_PROCESS_INIT;
 	int ret = 0;
 
-	if (!read_oneliner(&stash_oid, path,
-			   READ_ONELINER_SKIP_IF_EMPTY)) {
-		strbuf_release(&stash_oid);
-		return 0;
-	}
-	strbuf_trim(&stash_oid);
-
 	if (attempt_apply) {
 		child.git_cmd = 1;
 		child.no_stdout = 1;
 		child.no_stderr = 1;
 		argv_array_push(&child.args, "stash");
 		argv_array_push(&child.args, "apply");
-		argv_array_push(&child.args, stash_oid.buf);
+		argv_array_push(&child.args, stash_oid);
 		ret = run_command(&child);
 	}
 
@@ -3741,9 +3733,9 @@ static int apply_save_autostash(const char *path, int attempt_apply)
 		argv_array_push(&store.args, "-m");
 		argv_array_push(&store.args, "autostash");
 		argv_array_push(&store.args, "-q");
-		argv_array_push(&store.args, stash_oid.buf);
+		argv_array_push(&store.args, stash_oid);
 		if (run_command(&store))
-			ret = error(_("cannot store %s"), stash_oid.buf);
+			ret = error(_("cannot store %s"), stash_oid);
 		else
 			fprintf(stderr,
 				_("%s\n"
@@ -3755,6 +3747,23 @@ static int apply_save_autostash(const char *path, int attempt_apply)
 				_("Autostash exists; creating a new stash entry."));
 	}
 
+	return ret;
+}
+
+static int apply_save_autostash(const char *path, int attempt_apply)
+{
+	struct strbuf stash_oid = STRBUF_INIT;
+	int ret = 0;
+
+	if (!read_oneliner(&stash_oid, path,
+			   READ_ONELINER_SKIP_IF_EMPTY)) {
+		strbuf_release(&stash_oid);
+		return 0;
+	}
+	strbuf_trim(&stash_oid);
+
+	ret = apply_save_autostash_oid(stash_oid.buf, attempt_apply);
+
 	unlink(path);
 	strbuf_release(&stash_oid);
 	return ret;
@@ -3770,6 +3779,11 @@ int apply_autostash(const char *path)
 	return apply_save_autostash(path, 1);
 }
 
+int apply_autostash_oid(const char *stash_oid)
+{
+	return apply_save_autostash_oid(stash_oid, 1);
+}
+
 static const char *reflog_message(struct replay_opts *opts,
 	const char *sub_action, const char *fmt, ...)
 {
diff --git a/sequencer.h b/sequencer.h
index 306d4cecfb..5a85eeef92 100644
--- a/sequencer.h
+++ b/sequencer.h
@@ -195,6 +195,7 @@ void create_autostash(struct repository *r, const char *path,
 		      const char *default_reflog_action);
 int save_autostash(const char *path);
 int apply_autostash(const char *path);
+int apply_autostash_oid(const char *stash_oid);
 
 #define SUMMARY_INITIAL_COMMIT   (1 << 0)
 #define SUMMARY_SHOW_AUTHOR_DATE (1 << 1)

From a03b55530ab844974b7058042a015fcfcd9e7a53 Mon Sep 17 00:00:00 2001
From: Denton Liu <liu.denton@gmail.com>
Date: Tue, 7 Apr 2020 10:28:07 -0400
Subject: [PATCH 20/22] merge: teach --autostash option

In rebase, one can pass the `--autostash` option to cause the worktree
to be automatically stashed before continuing with the rebase. This
option is missing in merge, however.

Implement the `--autostash` option and corresponding `merge.autoStash`
option in merge which stashes before merging and then pops after.

This option is useful when a developer has some local changes on a topic
branch but they realize that their work depends on another branch.
Previously, they had to run something like

	git fetch ...
	git stash push
	git merge FETCH_HEAD
	git stash pop

but now, that is reduced to

	git fetch ...
	git merge --autostash FETCH_HEAD

When an autostash is generated, it is automatically reapplied to the
worktree only in three explicit situations:

	1. An incomplete merge is commit using `git commit`.
	2. A merge completes successfully.
	3. A merge is aborted using `git merge --abort`.

In all other situations where the merge state is removed using
remove_merge_branch_state() such as aborting a merge via
`git reset --hard`, the autostash is saved into the stash reflog
instead keeping the worktree clean.

Helped-by: Phillip Wood <phillip.wood@dunelm.org.uk>
Suggested-by: Alban Gruin <alban.gruin@gmail.com>
Signed-off-by: Denton Liu <liu.denton@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
---
 Documentation/config/merge.txt  |  10 +++
 Documentation/git-merge.txt     |  11 ++-
 Documentation/merge-options.txt |   8 ++
 branch.c                        |   1 +
 builtin/commit.c                |   2 +
 builtin/merge.c                 |  25 ++++++
 builtin/rebase.c                |   3 +-
 parse-options.h                 |   1 +
 path.c                          |   1 +
 path.h                          |   4 +-
 t/t3033-merge-toplevel.sh       |  22 ++++++
 t/t7600-merge.sh                | 132 ++++++++++++++++++++++++++++++++
 12 files changed, 214 insertions(+), 6 deletions(-)

diff --git a/Documentation/config/merge.txt b/Documentation/config/merge.txt
index 6a313937f8..cb2ed58907 100644
--- a/Documentation/config/merge.txt
+++ b/Documentation/config/merge.txt
@@ -70,6 +70,16 @@ merge.stat::
 	Whether to print the diffstat between ORIG_HEAD and the merge result
 	at the end of the merge.  True by default.
 
+merge.autoStash::
+	When set to true, automatically create a temporary stash entry
+	before the operation begins, and apply it after the operation
+	ends.  This means that you can run merge on a dirty worktree.
+	However, use with care: the final stash application after a
+	successful merge might result in non-trivial conflicts.
+	This option can be overridden by the `--no-autostash` and
+	`--autostash` options of linkgit:git-merge[1].
+	Defaults to false.
+
 merge.tool::
 	Controls which merge tool is used by linkgit:git-mergetool[1].
 	The list below shows the valid built-in values.
diff --git a/Documentation/git-merge.txt b/Documentation/git-merge.txt
index 092529c619..ec06b2f8c2 100644
--- a/Documentation/git-merge.txt
+++ b/Documentation/git-merge.txt
@@ -94,7 +94,8 @@ will be appended to the specified message.
 
 --abort::
 	Abort the current conflict resolution process, and
-	try to reconstruct the pre-merge state.
+	try to reconstruct the pre-merge state. If an autostash entry is
+	present, apply it to the worktree.
 +
 If there were uncommitted worktree changes present when the merge
 started, 'git merge --abort' will in some cases be unable to
@@ -102,11 +103,15 @@ reconstruct these changes. It is therefore recommended to always
 commit or stash your changes before running 'git merge'.
 +
 'git merge --abort' is equivalent to 'git reset --merge' when
-`MERGE_HEAD` is present.
+`MERGE_HEAD` is present unless `MERGE_AUTOSTASH` is also present in
+which case 'git merge --abort' applies the stash entry to the worktree
+whereas 'git reset --merge' will save the stashed changes in the stash
+reflog.
 
 --quit::
 	Forget about the current merge in progress. Leave the index
-	and the working tree as-is.
+	and the working tree as-is. If `MERGE_AUTOSTASH` is present, the
+	stash entry will be saved to the stash reflog.
 
 --continue::
 	After a 'git merge' stops due to conflicts you can conclude the
diff --git a/Documentation/merge-options.txt b/Documentation/merge-options.txt
index 40dc4f5e8c..3985e6d4a9 100644
--- a/Documentation/merge-options.txt
+++ b/Documentation/merge-options.txt
@@ -155,6 +155,14 @@ ifndef::git-pull[]
 	Note that not all merge strategies may support progress
 	reporting.
 
+--autostash::
+--no-autostash::
+	Automatically create a temporary stash entry before the operation
+	begins, and apply it after the operation ends.  This means
+	that you can run the operation on a dirty worktree.  However, use
+	with care: the final stash application after a successful
+	merge might result in non-trivial conflicts.
+
 endif::git-pull[]
 
 --allow-unrelated-histories::
diff --git a/branch.c b/branch.c
index 579494738a..2d9e7675a6 100644
--- a/branch.c
+++ b/branch.c
@@ -344,6 +344,7 @@ void remove_merge_branch_state(struct repository *r)
 	unlink(git_path_merge_rr(r));
 	unlink(git_path_merge_msg(r));
 	unlink(git_path_merge_mode(r));
+	save_autostash(git_path_merge_autostash(r));
 }
 
 void remove_branch_state(struct repository *r, int verbose)
diff --git a/builtin/commit.c b/builtin/commit.c
index 7ba33a3bec..c1b25d2954 100644
--- a/builtin/commit.c
+++ b/builtin/commit.c
@@ -1713,6 +1713,8 @@ int cmd_commit(int argc, const char **argv, const char *prefix)
 				     &oid, flags);
 	}
 
+	apply_autostash(git_path_merge_autostash(the_repository));
+
 	UNLEAK(err);
 	UNLEAK(sb);
 	return 0;
diff --git a/builtin/merge.c b/builtin/merge.c
index d127d2225f..f86ae90bfc 100644
--- a/builtin/merge.c
+++ b/builtin/merge.c
@@ -82,6 +82,7 @@ static int show_progress = -1;
 static int default_to_upstream = 1;
 static int signoff;
 static const char *sign_commit;
+static int autostash;
 static int no_verify;
 
 static struct strategy all_strategy[] = {
@@ -286,6 +287,7 @@ static struct option builtin_merge_options[] = {
 	OPT_SET_INT(0, "progress", &show_progress, N_("force progress reporting"), 1),
 	{ OPTION_STRING, 'S', "gpg-sign", &sign_commit, N_("key-id"),
 	  N_("GPG sign commit"), PARSE_OPT_OPTARG, NULL, (intptr_t) "" },
+	OPT_AUTOSTASH(&autostash),
 	OPT_BOOL(0, "overwrite-ignore", &overwrite_ignore, N_("update ignored files (default)")),
 	OPT_BOOL(0, "signoff", &signoff, N_("add Signed-off-by:")),
 	OPT_BOOL(0, "no-verify", &no_verify, N_("bypass pre-merge-commit and commit-msg hooks")),
@@ -475,6 +477,7 @@ static void finish(struct commit *head_commit,
 	/* Run a post-merge hook */
 	run_hook_le(NULL, "post-merge", squash ? "1" : "0", NULL);
 
+	apply_autostash(git_path_merge_autostash(the_repository));
 	strbuf_release(&reflog_message);
 }
 
@@ -634,6 +637,9 @@ static int git_merge_config(const char *k, const char *v, void *cb)
 		return 0;
 	} else if (!strcmp(k, "gpg.mintrustlevel")) {
 		check_trust_level = 0;
+	} else if (!strcmp(k, "merge.autostash")) {
+		autostash = git_config_bool(k, v);
+		return 0;
 	}
 
 	status = fmt_merge_msg_config(k, v, cb);
@@ -1281,6 +1287,7 @@ int cmd_merge(int argc, const char **argv, const char *prefix)
 	if (abort_current_merge) {
 		int nargc = 2;
 		const char *nargv[] = {"reset", "--merge", NULL};
+		struct strbuf stash_oid = STRBUF_INIT;
 
 		if (orig_argc != 2)
 			usage_msg_opt(_("--abort expects no arguments"),
@@ -1289,8 +1296,17 @@ int cmd_merge(int argc, const char **argv, const char *prefix)
 		if (!file_exists(git_path_merge_head(the_repository)))
 			die(_("There is no merge to abort (MERGE_HEAD missing)."));
 
+		if (read_oneliner(&stash_oid, git_path_merge_autostash(the_repository),
+		    READ_ONELINER_SKIP_IF_EMPTY))
+			unlink(git_path_merge_autostash(the_repository));
+
 		/* Invoke 'git reset --merge' */
 		ret = cmd_reset(nargc, nargv, prefix);
+
+		if (stash_oid.len)
+			apply_autostash_oid(stash_oid.buf);
+
+		strbuf_release(&stash_oid);
 		goto done;
 	}
 
@@ -1513,6 +1529,10 @@ int cmd_merge(int argc, const char **argv, const char *prefix)
 			goto done;
 		}
 
+		if (autostash)
+			create_autostash(the_repository,
+					 git_path_merge_autostash(the_repository),
+					 "merge");
 		if (checkout_fast_forward(the_repository,
 					  &head_commit->object.oid,
 					  &commit->object.oid,
@@ -1579,6 +1599,11 @@ int cmd_merge(int argc, const char **argv, const char *prefix)
 	if (fast_forward == FF_ONLY)
 		die(_("Not possible to fast-forward, aborting."));
 
+	if (autostash)
+		create_autostash(the_repository,
+				 git_path_merge_autostash(the_repository),
+				 "merge");
+
 	/* We are going to make a new commit. */
 	git_committer_info(IDENT_STRICT);
 
diff --git a/builtin/rebase.c b/builtin/rebase.c
index 08b89869b3..bc4fc69906 100644
--- a/builtin/rebase.c
+++ b/builtin/rebase.c
@@ -1376,8 +1376,7 @@ int cmd_rebase(int argc, const char **argv, const char *prefix)
 		{ OPTION_STRING, 'S', "gpg-sign", &gpg_sign, N_("key-id"),
 			N_("GPG-sign commits"),
 			PARSE_OPT_OPTARG, NULL, (intptr_t) "" },
-		OPT_BOOL(0, "autostash", &options.autostash,
-			 N_("automatically stash/stash pop before and after")),
+		OPT_AUTOSTASH(&options.autostash),
 		OPT_STRING_LIST('x', "exec", &exec, N_("exec"),
 				N_("add exec lines after each commit of the "
 				   "editable list")),
diff --git a/parse-options.h b/parse-options.h
index fece5ba628..46af942093 100644
--- a/parse-options.h
+++ b/parse-options.h
@@ -336,5 +336,6 @@ int parse_opt_passthru_argv(const struct option *, const char *, int);
 #define OPT_CLEANUP(v) OPT_STRING(0, "cleanup", v, N_("mode"), N_("how to strip spaces and #comments from message"))
 #define OPT_PATHSPEC_FROM_FILE(v) OPT_FILENAME(0, "pathspec-from-file", v, N_("read pathspec from file"))
 #define OPT_PATHSPEC_FILE_NUL(v)  OPT_BOOL(0, "pathspec-file-nul", v, N_("with --pathspec-from-file, pathspec elements are separated with NUL character"))
+#define OPT_AUTOSTASH(v) OPT_BOOL(0, "autostash", v, N_("automatically stash/stash pop before and after"))
 
 #endif
diff --git a/path.c b/path.c
index 88cf593007..d764738146 100644
--- a/path.c
+++ b/path.c
@@ -1535,5 +1535,6 @@ REPO_GIT_PATH_FUNC(merge_msg, "MERGE_MSG")
 REPO_GIT_PATH_FUNC(merge_rr, "MERGE_RR")
 REPO_GIT_PATH_FUNC(merge_mode, "MERGE_MODE")
 REPO_GIT_PATH_FUNC(merge_head, "MERGE_HEAD")
+REPO_GIT_PATH_FUNC(merge_autostash, "MERGE_AUTOSTASH")
 REPO_GIT_PATH_FUNC(fetch_head, "FETCH_HEAD")
 REPO_GIT_PATH_FUNC(shallow, "shallow")
diff --git a/path.h b/path.h
index 14d6dcad16..1f1bf8f87a 100644
--- a/path.h
+++ b/path.h
@@ -177,11 +177,12 @@ struct path_cache {
 	const char *merge_rr;
 	const char *merge_mode;
 	const char *merge_head;
+	const char *merge_autostash;
 	const char *fetch_head;
 	const char *shallow;
 };
 
-#define PATH_CACHE_INIT { NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL }
+#define PATH_CACHE_INIT { NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL }
 
 const char *git_path_cherry_pick_head(struct repository *r);
 const char *git_path_revert_head(struct repository *r);
@@ -190,6 +191,7 @@ const char *git_path_merge_msg(struct repository *r);
 const char *git_path_merge_rr(struct repository *r);
 const char *git_path_merge_mode(struct repository *r);
 const char *git_path_merge_head(struct repository *r);
+const char *git_path_merge_autostash(struct repository *r);
 const char *git_path_fetch_head(struct repository *r);
 const char *git_path_shallow(struct repository *r);
 
diff --git a/t/t3033-merge-toplevel.sh b/t/t3033-merge-toplevel.sh
index d314599428..e29c284b9b 100755
--- a/t/t3033-merge-toplevel.sh
+++ b/t/t3033-merge-toplevel.sh
@@ -142,6 +142,17 @@ test_expect_success 'refuse two-project merge by default' '
 	test_must_fail git merge five
 '
 
+test_expect_success 'refuse two-project merge by default, quit before --autostash happens' '
+	t3033_reset &&
+	git reset --hard four &&
+	echo change >>one.t &&
+	git diff >expect &&
+	test_must_fail git merge --autostash five 2>err &&
+	test_i18ngrep ! "stash" err &&
+	git diff >actual &&
+	test_cmp expect actual
+'
+
 test_expect_success 'two-project merge with --allow-unrelated-histories' '
 	t3033_reset &&
 	git reset --hard four &&
@@ -149,4 +160,15 @@ test_expect_success 'two-project merge with --allow-unrelated-histories' '
 	git diff --exit-code five
 '
 
+test_expect_success 'two-project merge with --allow-unrelated-histories with --autostash' '
+	t3033_reset &&
+	git reset --hard four &&
+	echo change >>one.t &&
+	git diff one.t >expect &&
+	git merge --allow-unrelated-histories --autostash five 2>err &&
+	test_i18ngrep "Applied autostash." err &&
+	git diff one.t >actual &&
+	test_cmp expect actual
+'
+
 test_done
diff --git a/t/t7600-merge.sh b/t/t7600-merge.sh
index 4fa0ef8e3b..5883a6adc3 100755
--- a/t/t7600-merge.sh
+++ b/t/t7600-merge.sh
@@ -30,13 +30,17 @@ Testing basic merge operations/option parsing.
 . "$TEST_DIRECTORY"/lib-gpg.sh
 
 test_write_lines 1 2 3 4 5 6 7 8 9 >file
+cp file file.orig
 test_write_lines '1 X' 2 3 4 5 6 7 8 9 >file.1
+test_write_lines 1 2 '3 X' 4 5 6 7 8 9 >file.3
 test_write_lines 1 2 3 4 '5 X' 6 7 8 9 >file.5
 test_write_lines 1 2 3 4 5 6 7 8 '9 X' >file.9
 test_write_lines 1 2 3 4 5 6 7 8 '9 Y' >file.9y
 test_write_lines '1 X' 2 3 4 5 6 7 8 9 >result.1
 test_write_lines '1 X' 2 3 4 '5 X' 6 7 8 9 >result.1-5
+test_write_lines '1 X' 2 3 4 5 6 7 8 '9 X' >result.1-9
 test_write_lines '1 X' 2 3 4 '5 X' 6 7 8 '9 X' >result.1-5-9
+test_write_lines '1 X' 2 '3 X' 4 '5 X' 6 7 8 '9 X' >result.1-3-5-9
 test_write_lines 1 2 3 4 5 6 7 8 '9 Z' >result.9z
 
 create_merge_msgs () {
@@ -675,6 +679,134 @@ test_expect_success 'refresh the index before merging' '
 	git merge c3
 '
 
+test_expect_success 'merge with --autostash' '
+	git reset --hard c1 &&
+	git merge-file file file.orig file.9 &&
+	git merge --autostash c2 2>err &&
+	test_i18ngrep "Applied autostash." err &&
+	git show HEAD:file >merge-result &&
+	test_cmp result.1-5 merge-result &&
+	test_cmp result.1-5-9 file
+'
+
+test_expect_success 'merge with merge.autoStash' '
+	test_config merge.autoStash true &&
+	git reset --hard c1 &&
+	git merge-file file file.orig file.9 &&
+	git merge c2 2>err &&
+	test_i18ngrep "Applied autostash." err &&
+	git show HEAD:file >merge-result &&
+	test_cmp result.1-5 merge-result &&
+	test_cmp result.1-5-9 file
+'
+
+test_expect_success 'fast-forward merge with --autostash' '
+	git reset --hard c0 &&
+	git merge-file file file.orig file.5 &&
+	git merge --autostash c1 2>err &&
+	test_i18ngrep "Applied autostash." err &&
+	test_cmp result.1-5 file
+'
+
+test_expect_success 'octopus merge with --autostash' '
+	git reset --hard c1 &&
+	git merge-file file file.orig file.3 &&
+	git merge --autostash c2 c3 2>err &&
+	test_i18ngrep "Applied autostash." err &&
+	git show HEAD:file >merge-result &&
+	test_cmp result.1-5-9 merge-result &&
+	test_cmp result.1-3-5-9 file
+'
+
+test_expect_success 'conflicted merge with --autostash, --abort restores stash' '
+	git reset --hard c3 &&
+	cp file.1 file &&
+	test_must_fail git merge --autostash c7 &&
+	git merge --abort 2>err &&
+	test_i18ngrep "Applied autostash." err &&
+	test_cmp file.1 file
+'
+
+test_expect_success 'completed merge (git commit) with --no-commit and --autostash' '
+	git reset --hard c1 &&
+	git merge-file file file.orig file.9 &&
+	git diff >expect &&
+	git merge --no-commit --autostash c2 &&
+	git stash show -p MERGE_AUTOSTASH >actual &&
+	test_cmp expect actual &&
+	git commit 2>err &&
+	test_i18ngrep "Applied autostash." err &&
+	git show HEAD:file >merge-result &&
+	test_cmp result.1-5 merge-result &&
+	test_cmp result.1-5-9 file
+'
+
+test_expect_success 'completed merge (git merge --continue) with --no-commit and --autostash' '
+	git reset --hard c1 &&
+	git merge-file file file.orig file.9 &&
+	git diff >expect &&
+	git merge --no-commit --autostash c2 &&
+	git stash show -p MERGE_AUTOSTASH >actual &&
+	test_cmp expect actual &&
+	git merge --continue 2>err &&
+	test_i18ngrep "Applied autostash." err &&
+	git show HEAD:file >merge-result &&
+	test_cmp result.1-5 merge-result &&
+	test_cmp result.1-5-9 file
+'
+
+test_expect_success 'aborted merge (merge --abort) with --no-commit and --autostash' '
+	git reset --hard c1 &&
+	git merge-file file file.orig file.9 &&
+	git diff >expect &&
+	git merge --no-commit --autostash c2 &&
+	git stash show -p MERGE_AUTOSTASH >actual &&
+	test_cmp expect actual &&
+	git merge --abort 2>err &&
+	test_i18ngrep "Applied autostash." err &&
+	git diff >actual &&
+	test_cmp expect actual
+'
+
+test_expect_success 'aborted merge (reset --hard) with --no-commit and --autostash' '
+	git reset --hard c1 &&
+	git merge-file file file.orig file.9 &&
+	git diff >expect &&
+	git merge --no-commit --autostash c2 &&
+	git stash show -p MERGE_AUTOSTASH >actual &&
+	test_cmp expect actual &&
+	git reset --hard 2>err &&
+	test_i18ngrep "Autostash exists; creating a new stash entry." err &&
+	git diff --exit-code
+'
+
+test_expect_success 'quit merge with --no-commit and --autostash' '
+	git reset --hard c1 &&
+	git merge-file file file.orig file.9 &&
+	git diff >expect &&
+	git merge --no-commit --autostash c2 &&
+	git stash show -p MERGE_AUTOSTASH >actual &&
+	test_cmp expect actual &&
+	git diff HEAD >expect &&
+	git merge --quit 2>err &&
+	test_i18ngrep "Autostash exists; creating a new stash entry." err &&
+	git diff HEAD >actual &&
+	test_cmp expect actual
+'
+
+test_expect_success 'merge with conflicted --autostash changes' '
+	git reset --hard c1 &&
+	git merge-file file file.orig file.9y &&
+	git diff >expect &&
+	test_when_finished "test_might_fail git stash drop" &&
+	git merge --autostash c3 2>err &&
+	test_i18ngrep "Applying autostash resulted in conflicts." err &&
+	git show HEAD:file >merge-result &&
+	test_cmp result.1-9 merge-result &&
+	git stash show -p >actual &&
+	test_cmp expect actual
+'
+
 cat >expected.branch <<\EOF
 Merge branch 'c5-branch' (early part)
 EOF

From f8a178580719a93040a49cf25624f1d56d0147f1 Mon Sep 17 00:00:00 2001
From: Denton Liu <liu.denton@gmail.com>
Date: Tue, 7 Apr 2020 10:28:08 -0400
Subject: [PATCH 21/22] t5520: make test_pull_autostash() accept
 expect_parent_num

Before, test_pull_autostash() was hardcoded to run
`test_cmp_rev HEAD^ copy` to test that a rebase happened. However, in a
future patch, we plan on testing merging as well. Make
test_pull_autostash() accept a parent number as an argument so that, in
the future, we can test if a merge happened in addition to a rebase.

Signed-off-by: Denton Liu <liu.denton@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
---
 t/t5520-pull.sh | 14 ++++++++------
 1 file changed, 8 insertions(+), 6 deletions(-)

diff --git a/t/t5520-pull.sh b/t/t5520-pull.sh
index 2f86fca042..f610dc14de 100755
--- a/t/t5520-pull.sh
+++ b/t/t5520-pull.sh
@@ -10,11 +10,13 @@ modify () {
 }
 
 test_pull_autostash () {
+	expect_parent_num="$1" &&
+	shift &&
 	git reset --hard before-rebase &&
 	echo dirty >new_file &&
 	git add new_file &&
 	git pull "$@" . copy &&
-	test_cmp_rev HEAD^ copy &&
+	test_cmp_rev HEAD^"$expect_parent_num" copy &&
 	echo dirty >expect &&
 	test_cmp expect new_file &&
 	echo "modified again" >expect &&
@@ -369,22 +371,22 @@ test_expect_success '--rebase fails with multiple branches' '
 
 test_expect_success 'pull --rebase succeeds with dirty working directory and rebase.autostash set' '
 	test_config rebase.autostash true &&
-	test_pull_autostash --rebase
+	test_pull_autostash 1 --rebase
 '
 
 test_expect_success 'pull --rebase --autostash & rebase.autostash=true' '
 	test_config rebase.autostash true &&
-	test_pull_autostash --rebase --autostash
+	test_pull_autostash 1 --rebase --autostash
 '
 
 test_expect_success 'pull --rebase --autostash & rebase.autostash=false' '
 	test_config rebase.autostash false &&
-	test_pull_autostash --rebase --autostash
+	test_pull_autostash 1 --rebase --autostash
 '
 
 test_expect_success 'pull --rebase --autostash & rebase.autostash unset' '
 	test_unconfig rebase.autostash &&
-	test_pull_autostash --rebase --autostash
+	test_pull_autostash 1 --rebase --autostash
 '
 
 test_expect_success 'pull --rebase --no-autostash & rebase.autostash=true' '
@@ -422,7 +424,7 @@ test_expect_success 'pull.rebase' '
 
 test_expect_success 'pull --autostash & pull.rebase=true' '
 	test_config pull.rebase true &&
-	test_pull_autostash --autostash
+	test_pull_autostash 1 --autostash
 '
 
 test_expect_success 'pull --no-autostash & pull.rebase=true' '

From d9f15d37f1a545305988f6b2bb40de1fbf0049cf Mon Sep 17 00:00:00 2001
From: Denton Liu <liu.denton@gmail.com>
Date: Tue, 7 Apr 2020 10:28:09 -0400
Subject: [PATCH 22/22] pull: pass --autostash to merge

Before, `--autostash` only worked with `git pull --rebase`. However, in
the last patch, merge learned `--autostash` as well so there's no reason
why we should have this restriction anymore. Teach pull to pass
`--autostash` to merge, just like it did for rebase.

Signed-off-by: Denton Liu <liu.denton@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
---
 Documentation/git-pull.txt      |  9 -------
 Documentation/merge-options.txt |  4 +--
 builtin/pull.c                  |  9 ++++---
 t/t5520-pull.sh                 | 43 +++++++++++++++++++++++++++------
 4 files changed, 42 insertions(+), 23 deletions(-)

diff --git a/Documentation/git-pull.txt b/Documentation/git-pull.txt
index dfb901f8b8..ba3772de9f 100644
--- a/Documentation/git-pull.txt
+++ b/Documentation/git-pull.txt
@@ -133,15 +133,6 @@ unless you have read linkgit:git-rebase[1] carefully.
 --no-rebase::
 	Override earlier --rebase.
 
---autostash::
---no-autostash::
-	Before starting rebase, stash local modifications away (see
-	linkgit:git-stash[1]) if needed, and apply the stash entry when
-	done. `--no-autostash` is useful to override the `rebase.autoStash`
-	configuration variable (see linkgit:git-config[1]).
-+
-This option is only valid when "--rebase" is used.
-
 Options related to fetching
 ~~~~~~~~~~~~~~~~~~~~~~~~~~~
 
diff --git a/Documentation/merge-options.txt b/Documentation/merge-options.txt
index 3985e6d4a9..48bfcda084 100644
--- a/Documentation/merge-options.txt
+++ b/Documentation/merge-options.txt
@@ -155,6 +155,8 @@ ifndef::git-pull[]
 	Note that not all merge strategies may support progress
 	reporting.
 
+endif::git-pull[]
+
 --autostash::
 --no-autostash::
 	Automatically create a temporary stash entry before the operation
@@ -163,8 +165,6 @@ ifndef::git-pull[]
 	with care: the final stash application after a successful
 	merge might result in non-trivial conflicts.
 
-endif::git-pull[]
-
 --allow-unrelated-histories::
 	By default, `git merge` command refuses to merge histories
 	that do not share a common ancestor.  This option can be
diff --git a/builtin/pull.c b/builtin/pull.c
index 3e624d1e00..9beb4841d1 100644
--- a/builtin/pull.c
+++ b/builtin/pull.c
@@ -163,7 +163,7 @@ static struct option pull_options[] = {
 		N_("verify that the named commit has a valid GPG signature"),
 		PARSE_OPT_NOARG),
 	OPT_BOOL(0, "autostash", &opt_autostash,
-		N_("automatically stash/stash pop before and after rebase")),
+		N_("automatically stash/stash pop before and after")),
 	OPT_PASSTHRU_ARGV('s', "strategy", &opt_strategies, N_("strategy"),
 		N_("merge strategy to use"),
 		0),
@@ -661,6 +661,10 @@ static int run_merge(void)
 	argv_array_pushv(&args, opt_strategy_opts.argv);
 	if (opt_gpg_sign)
 		argv_array_push(&args, opt_gpg_sign);
+	if (opt_autostash == 0)
+		argv_array_push(&args, "--no-autostash");
+	else if (opt_autostash == 1)
+		argv_array_push(&args, "--autostash");
 	if (opt_allow_unrelated_histories > 0)
 		argv_array_push(&args, "--allow-unrelated-histories");
 
@@ -908,9 +912,6 @@ int cmd_pull(int argc, const char **argv, const char *prefix)
 	if (get_oid("HEAD", &orig_head))
 		oidclr(&orig_head);
 
-	if (!opt_rebase && opt_autostash != -1)
-		die(_("--[no-]autostash option is only valid with --rebase."));
-
 	autostash = config_autostash;
 	if (opt_rebase) {
 		if (opt_autostash != -1)
diff --git a/t/t5520-pull.sh b/t/t5520-pull.sh
index f610dc14de..37535d63a9 100755
--- a/t/t5520-pull.sh
+++ b/t/t5520-pull.sh
@@ -28,7 +28,7 @@ test_pull_autostash_fail () {
 	echo dirty >new_file &&
 	git add new_file &&
 	test_must_fail git pull "$@" . copy 2>err &&
-	test_i18ngrep "uncommitted changes." err
+	test_i18ngrep "\(uncommitted changes.\)\|\(overwritten by merge:\)" err
 }
 
 test_expect_success setup '
@@ -404,13 +404,40 @@ test_expect_success 'pull --rebase --no-autostash & rebase.autostash unset' '
 	test_pull_autostash_fail --rebase --no-autostash
 '
 
-for i in --autostash --no-autostash
-do
-	test_expect_success "pull $i (without --rebase) is illegal" '
-		test_must_fail git pull $i . copy 2>err &&
-		test_i18ngrep "only valid with --rebase" err
-	'
-done
+test_expect_success 'pull succeeds with dirty working directory and merge.autostash set' '
+	test_config merge.autostash true &&
+	test_pull_autostash 2
+'
+
+test_expect_success 'pull --autostash & merge.autostash=true' '
+	test_config merge.autostash true &&
+	test_pull_autostash 2 --autostash
+'
+
+test_expect_success 'pull --autostash & merge.autostash=false' '
+	test_config merge.autostash false &&
+	test_pull_autostash 2 --autostash
+'
+
+test_expect_success 'pull --autostash & merge.autostash unset' '
+	test_unconfig merge.autostash &&
+	test_pull_autostash 2 --autostash
+'
+
+test_expect_success 'pull --no-autostash & merge.autostash=true' '
+	test_config merge.autostash true &&
+	test_pull_autostash_fail --no-autostash
+'
+
+test_expect_success 'pull --no-autostash & merge.autostash=false' '
+	test_config merge.autostash false &&
+	test_pull_autostash_fail --no-autostash
+'
+
+test_expect_success 'pull --no-autostash & merge.autostash unset' '
+	test_unconfig merge.autostash &&
+	test_pull_autostash_fail --no-autostash
+'
 
 test_expect_success 'pull.rebase' '
 	git reset --hard before-rebase &&