tests: optionally skip `git rebase -p` tests

The `--preserve-merges` mode of the `rebase` command is slated to be
deprecated soon, as the more powerful `--rebase-merges` mode is
available now, and the latter was designed with the express intent to
address the shortcomings of `--preserve-merges`' design (e.g. the
inability to reorder commits in an interactive rebase).

As such, we will eventually even remove the `--preserve-merges` support,
and along with it, its tests.

In preparation for this, and also to allow the Windows phase of our
automated tests to save some well-needed time when running the test
suite, this commit introduces a new prerequisite REBASE_P, which can be
forced to being unmet by setting the environment variable
`GIT_TEST_SKIP_REBASE_P` to any non-empty string.

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

t/t3404-rebase-interactive.sh

@@ -312,7 +312,7 @@ test_expect_success 'retain authorship when squashing' '
 	git show HEAD | grep "^Author: Twerp Snog"
 '
 
-test_expect_success '-p handles "no changes" gracefully' '
+test_expect_success REBASE_P '-p handles "no changes" gracefully' '
 	HEAD=$(git rev-parse HEAD) &&
 	set_fake_editor &&
 	git rebase -i -p HEAD^ &&
@@ -322,7 +322,7 @@ test_expect_success '-p handles "no changes" gracefully' '
 	test $HEAD = $(git rev-parse HEAD)
 '
 
-test_expect_failure 'exchange two commits with -p' '
+test_expect_failure REBASE_P 'exchange two commits with -p' '
 	git checkout H &&
 	set_fake_editor &&
 	FAKE_LINES="2 1" git rebase -i -p HEAD~2 &&
@@ -330,7 +330,7 @@ test_expect_failure 'exchange two commits with -p' '
 	test G = $(git cat-file commit HEAD | sed -ne \$p)
 '
 
-test_expect_success 'preserve merges with -p' '
+test_expect_success REBASE_P 'preserve merges with -p' '
 	git checkout -b to-be-preserved master^ &&
 	: > unrelated-file &&
 	git add unrelated-file &&
@@ -373,7 +373,7 @@ test_expect_success 'preserve merges with -p' '
 	test $(git show HEAD:unrelated-file) = 1
 '
 
-test_expect_success 'edit ancestor with -p' '
+test_expect_success REBASE_P 'edit ancestor with -p' '
 	set_fake_editor &&
 	FAKE_LINES="1 2 edit 3 4" git rebase -i -p HEAD~3 &&
 	echo 2 > unrelated-file &&

t/t3408-rebase-multi-line.sh

@@ -52,7 +52,7 @@ test_expect_success rebase '
 	test_cmp expect actual
 
 '
-test_expect_success rebasep '
+test_expect_success REBASE_P rebasep '
 
 	git checkout side-merge &&
 	git rebase -p side &&

t/t3409-rebase-preserve-merges.sh

@@ -8,6 +8,11 @@ Run "git rebase -p" and check that merges are properly carried along
 '
 . ./test-lib.sh
 
+if ! test_have_prereq REBASE_P; then
+	skip_all='skipping git rebase -p tests, as asked for'
+	test_done
+fi
+
 GIT_AUTHOR_EMAIL=bogus_email_address
 export GIT_AUTHOR_EMAIL
 

t/t3410-rebase-preserve-dropped-merges.sh

@@ -11,6 +11,11 @@ rewritten.
 '
 . ./test-lib.sh
 
+if ! test_have_prereq REBASE_P; then
+	skip_all='skipping git rebase -p tests, as asked for'
+	test_done
+fi
+
 # set up two branches like this:
 #
 # A - B - C - D - E

t/t3411-rebase-preserve-around-merges.sh

@@ -10,6 +10,11 @@ a merge to before the merge.
 '
 . ./test-lib.sh
 
+if ! test_have_prereq REBASE_P; then
+	skip_all='skipping git rebase -p tests, as asked for'
+	test_done
+fi
+
 . "$TEST_DIRECTORY"/lib-rebase.sh
 
 set_fake_editor

t/t3412-rebase-root.sh

@@ -86,14 +86,14 @@ test_expect_success 'pre-rebase got correct input (4)' '
 	test "z$(cat .git/PRE-REBASE-INPUT)" = z--root,work4
 '
 
-test_expect_success 'rebase -i -p with linear history' '
+test_expect_success REBASE_P 'rebase -i -p with linear history' '
 	git checkout -b work5 other &&
 	git rebase -i -p --root --onto master &&
 	git log --pretty=tformat:"%s" > rebased5 &&
 	test_cmp expect rebased5
 '
 
-test_expect_success 'pre-rebase got correct input (5)' '
+test_expect_success REBASE_P 'pre-rebase got correct input (5)' '
 	test "z$(cat .git/PRE-REBASE-INPUT)" = z--root,
 '
 
@@ -120,7 +120,7 @@ commit work6~4
 1
 EOF
 
-test_expect_success 'rebase -i -p with merge' '
+test_expect_success REBASE_P 'rebase -i -p with merge' '
 	git checkout -b work6 other &&
 	git rebase -i -p --root --onto master &&
 	log_with_names work6 > rebased6 &&
@@ -155,7 +155,7 @@ commit work7~5
 1
 EOF
 
-test_expect_success 'rebase -i -p with two roots' '
+test_expect_success REBASE_P 'rebase -i -p with two roots' '
 	git checkout -b work7 other &&
 	git rebase -i -p --root --onto master &&
 	log_with_names work7 > rebased7 &&
@@ -261,7 +261,7 @@ commit conflict3~6
 1
 EOF
 
-test_expect_success 'rebase -i -p --root with conflict (first part)' '
+test_expect_success REBASE_P 'rebase -i -p --root with conflict (first part)' '
 	git checkout -b conflict3 other &&
 	test_must_fail git rebase -i -p --root --onto master &&
 	git ls-files -u | grep "B$"
@@ -272,7 +272,7 @@ test_expect_success 'fix the conflict' '
 	git add B
 '
 
-test_expect_success 'rebase -i -p --root with conflict (second part)' '
+test_expect_success REBASE_P 'rebase -i -p --root with conflict (second part)' '
 	git rebase --continue &&
 	log_with_names conflict3 >out &&
 	test_cmp expect-conflict-p out

t/t3414-rebase-preserve-onto.sh

@@ -10,6 +10,11 @@ aren'"'"'t on top of $ONTO, even if they are on top of $UPSTREAM.
 '
 . ./test-lib.sh
 
+if ! test_have_prereq REBASE_P; then
+	skip_all='skipping git rebase -p tests, as asked for'
+	test_done
+fi
+
 . "$TEST_DIRECTORY"/lib-rebase.sh
 
 # Set up branches like this:

t/t3418-rebase-continue.sh

@@ -106,7 +106,7 @@ test_expect_success 'rebase -i --continue handles merge strategy and options' '
 	test -f funny.was.run
 '
 
-test_expect_success 'rebase passes merge strategy options correctly' '
+test_expect_success REBASE_P 'rebase passes merge strategy options correctly' '
 	rm -fr .git/rebase-* &&
 	git reset --hard commit-new-file-F3-on-topic-branch &&
 	test_commit theirs-to-merge &&
@@ -241,6 +241,6 @@ test_rerere_autoupdate
 test_rerere_autoupdate -m
 GIT_SEQUENCE_EDITOR=: && export GIT_SEQUENCE_EDITOR
 test_rerere_autoupdate -i
-test_rerere_autoupdate --preserve-merges
+test_have_prereq !REBASE_P || test_rerere_autoupdate --preserve-merges
 
 test_done

t/t3421-rebase-topology-linear.sh

@@ -29,7 +29,7 @@ test_run_rebase () {
 test_run_rebase success ''
 test_run_rebase success -m
 test_run_rebase success -i
-test_run_rebase success -p
+test_have_prereq !REBASE_P || test_run_rebase success -p
 
 test_run_rebase () {
 	result=$1
@@ -43,7 +43,7 @@ test_run_rebase () {
 test_run_rebase success ''
 test_run_rebase success -m
 test_run_rebase success -i
-test_run_rebase success -p
+test_have_prereq !REBASE_P || test_run_rebase success -p
 
 test_run_rebase () {
 	result=$1
@@ -59,7 +59,7 @@ test_run_rebase () {
 test_run_rebase success ''
 test_run_rebase success -m
 test_run_rebase success -i
-test_run_rebase failure -p
+test_have_prereq !REBASE_P || test_run_rebase failure -p
 
 test_run_rebase () {
 	result=$1
@@ -73,7 +73,7 @@ test_run_rebase () {
 test_run_rebase success ''
 test_run_rebase success -m
 test_run_rebase success -i
-test_run_rebase success -p
+test_have_prereq !REBASE_P || test_run_rebase success -p
 
 #       f
 #      /
@@ -113,7 +113,7 @@ test_run_rebase () {
 test_run_rebase success ''
 test_run_rebase failure -m
 test_run_rebase success -i
-test_run_rebase success -p
+test_have_prereq !REBASE_P || test_run_rebase success -p
 
 test_run_rebase () {
 	result=$1
@@ -128,7 +128,7 @@ test_run_rebase () {
 test_run_rebase success ''
 test_run_rebase failure -m
 test_run_rebase success -i
-test_run_rebase success -p
+test_have_prereq !REBASE_P || test_run_rebase success -p
 
 test_run_rebase () {
 	result=$1
@@ -143,7 +143,7 @@ test_run_rebase () {
 test_run_rebase success ''
 test_run_rebase failure -m
 test_run_rebase success -i
-test_run_rebase success -p
+test_have_prereq !REBASE_P || test_run_rebase success -p
 
 test_run_rebase () {
 	result=$1
@@ -158,7 +158,7 @@ test_run_rebase () {
 test_run_rebase success ''
 test_run_rebase success -m
 test_run_rebase success -i
-test_run_rebase success -p
+test_have_prereq !REBASE_P || test_run_rebase success -p
 
 # a---b---c---j!
 #      \
@@ -186,7 +186,7 @@ test_run_rebase () {
 test_run_rebase success ''
 test_run_rebase success -m
 test_run_rebase success -i
-test_run_rebase success -p
+test_have_prereq !REBASE_P || test_run_rebase success -p
 
 test_run_rebase () {
 	result=$1
@@ -201,7 +201,7 @@ test_run_rebase () {
 test_run_rebase success ''
 test_run_rebase success -m
 test_run_rebase success -i
-test_run_rebase failure -p
+test_have_prereq !REBASE_P || test_run_rebase failure -p
 
 test_run_rebase () {
 	result=$1
@@ -216,7 +216,7 @@ test_run_rebase () {
 test_run_rebase success ''
 test_run_rebase success -m
 test_run_rebase success -i
-test_run_rebase failure -p
+test_have_prereq !REBASE_P || test_run_rebase failure -p
 test_run_rebase success --rebase-merges
 
 #       m
@@ -256,7 +256,7 @@ test_run_rebase () {
 test_run_rebase success ''
 test_run_rebase success -m
 test_run_rebase success -i
-test_run_rebase success -p
+test_have_prereq !REBASE_P || test_run_rebase success -p
 
 test_run_rebase () {
 	result=$1
@@ -271,7 +271,7 @@ test_run_rebase () {
 test_run_rebase success ''
 test_run_rebase success -m
 test_run_rebase success -i
-test_run_rebase failure -p
+test_have_prereq !REBASE_P || test_run_rebase failure -p
 
 test_run_rebase () {
 	result=$1
@@ -286,7 +286,7 @@ test_run_rebase () {
 test_run_rebase success ''
 test_run_rebase failure -m
 test_run_rebase success -i
-test_run_rebase success -p
+test_have_prereq !REBASE_P || test_run_rebase success -p
 
 test_run_rebase () {
 	result=$1
@@ -302,7 +302,7 @@ test_run_rebase () {
 test_run_rebase success ''
 test_run_rebase success -m
 test_run_rebase success -i
-test_run_rebase failure -p
+test_have_prereq !REBASE_P || test_run_rebase failure -p
 
 test_run_rebase () {
 	result=$1
@@ -317,7 +317,7 @@ test_run_rebase () {
 test_run_rebase success ''
 test_run_rebase failure -m
 test_run_rebase success -i
-test_run_rebase failure -p
+test_have_prereq !REBASE_P || test_run_rebase failure -p
 
 test_run_rebase () {
 	result=$1
@@ -331,7 +331,7 @@ test_run_rebase () {
 test_run_rebase success ''
 test_run_rebase success -m
 test_run_rebase success -i
-test_run_rebase failure -p
+test_have_prereq !REBASE_P || test_run_rebase failure -p
 
 test_run_rebase () {
 	result=$1
@@ -346,6 +346,6 @@ test_run_rebase () {
 test_run_rebase success ''
 test_run_rebase success -m
 test_run_rebase success -i
-test_run_rebase success -p
+test_have_prereq !REBASE_P || test_run_rebase success -p
 
 test_done

t/t3425-rebase-topology-merges.sh

@@ -109,6 +109,11 @@ test_run_rebase success 'd e n o' ''
 test_run_rebase success 'd e n o' -m
 test_run_rebase success 'd n o e' -i
 
+if ! test_have_prereq REBASE_P; then
+	skip_all='skipping git rebase -p tests, as asked for'
+	test_done
+fi
+
 test_expect_success "rebase -p is no-op in non-linear history" "
 	reset_rebase &&
 	git rebase -p d w &&

t/t5520-pull.sh

@@ -461,7 +461,8 @@ test_expect_success 'pull.rebase=1 is treated as true and flattens keep-merge' '
 	test file3 = "$(git show HEAD:file3.t)"
 '
 
-test_expect_success 'pull.rebase=preserve rebases and merges keep-merge' '
+test_expect_success REBASE_P \
+	'pull.rebase=preserve rebases and merges keep-merge' '
 	git reset --hard before-preserve-rebase &&
 	test_config pull.rebase preserve &&
 	git pull . copy &&
@@ -514,7 +515,8 @@ test_expect_success '--rebase=true rebases and flattens keep-merge' '
 	test file3 = "$(git show HEAD:file3.t)"
 '
 
-test_expect_success '--rebase=preserve rebases and merges keep-merge' '
+test_expect_success REBASE_P \
+	'--rebase=preserve rebases and merges keep-merge' '
 	git reset --hard before-preserve-rebase &&
 	test_config pull.rebase true &&
 	git pull --rebase=preserve . copy &&

t/t7505-prepare-commit-msg-hook.sh

@@ -253,7 +253,7 @@ test_rebase () {
 }
 
 test_rebase success -i
-test_rebase success -p
+test_have_prereq !REBASE_P || test_rebase success -p
 
 test_expect_success 'with hook (cherry-pick)' '
 	test_when_finished "git checkout -f master" &&

t/t7517-per-repo-email.sh

@@ -72,12 +72,14 @@ test_expect_success 'noop interactive rebase does not care about ident' '
 	git rebase -i HEAD^
 '
 
-test_expect_success 'fast-forward rebase does not care about ident (preserve)' '
+test_expect_success REBASE_P \
+	'fast-forward rebase does not care about ident (preserve)' '
 	git checkout -B tmp side-without-commit &&
 	git rebase -p master
 '
 
-test_expect_success 'non-fast-forward rebase refuses to write commits (preserve)' '
+test_expect_success REBASE_P \
+	'non-fast-forward rebase refuses to write commits (preserve)' '
 	test_when_finished "git rebase --abort || true" &&
 	git checkout -B tmp side-with-commit &&
 	test_must_fail git rebase -p master

t/test-lib.sh

@@ -1268,3 +1268,7 @@ test_lazy_prereq CURL '
 test_lazy_prereq SHA1 '
 	test $(git hash-object /dev/null) = e69de29bb2d1d6434b8b29ae775ad8c2e48c5391
 '
+
+test_lazy_prereq REBASE_P '
+	test -z "$GIT_TEST_SKIP_REBASE_P"
+'