git-merge: add support for branch.<name>.mergeoptions

This enables per branch configuration of merge options. Currently, the most
useful options to specify per branch are --squash, --summary/--no-summary
and possibly --strategy, but all options are supported.

Note: Options containing whitespace will _not_ be handled correctly. Luckily,
the only option which can include whitespace is --message and it doesn't
make much sense to give that option a default value.

Signed-off-by: Lars Hjemli <hjemli@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

Documentation/config.txt

@@ -337,6 +337,12 @@ branch.<name>.merge::
 	branch.<name>.merge to the desired branch, and use the special setting
 	`.` (a period) for branch.<name>.remote.
 
+branch.<name>.mergeoptions::
+	Sets default options for merging into branch <name>. The syntax and
+	supported options are equal to that of gitlink:git-merge[1], but
+	option values containing whitespace characters are currently not
+	supported.
+
 clean.requireForce::
 	A boolean to make git-clean do nothing unless given -f or -n.  Defaults
 	to false.

Documentation/git-merge.txt

@@ -58,6 +58,10 @@ merge.verbosity::
 	above outputs debugging information.  The default is level 2.
 	Can be overriden by 'GIT_MERGE_VERBOSITY' environment variable.
 
+branch.<name>.mergeoptions::
+	Sets default options for merging into branch <name>. The syntax and
+	supported options are equal to that of git-merge, but option values
+	containing whitespace characters are currently not supported.
 
 HOW MERGE WORKS
 ---------------

git-merge.sh

@@ -168,9 +168,30 @@ parse_option () {
 	args_left=$#
 }
 
+parse_config () {
+	while test $# -gt 0
+	do
+		parse_option "$@" || usage
+		while test $args_left -lt $#
+		do
+			shift
+		done
+	done
+}
+
 test $# != 0 || usage
 
 have_message=
+
+if branch=$(git-symbolic-ref -q HEAD)
+then
+	mergeopts=$(git config "branch.${branch#refs/heads/}.mergeoptions")
+	if test -n "$mergeopts"
+	then
+		parse_config $mergeopts
+	fi
+fi
+
 while parse_option "$@"
 do
 	while test $args_left -lt $#

t/t7600-merge.sh

@@ -341,4 +341,58 @@ test_expect_success 'merge c1 with c2 and c3 (squash)' '
 
 test_debug 'gitk --all'
 
+test_expect_success 'merge c1 with c2 (no-commit in config)' '
+	git reset --hard c1 &&
+	git config branch.master.mergeoptions "--no-commit" &&
+	git merge c2 &&
+	verify_merge file result.1-5 &&
+	verify_head $c1 &&
+	verify_mergeheads $c2
+'
+
+test_debug 'gitk --all'
+
+test_expect_success 'merge c1 with c2 (squash in config)' '
+	git reset --hard c1 &&
+	git config branch.master.mergeoptions "--squash" &&
+	git merge c2 &&
+	verify_merge file result.1-5 &&
+	verify_head $c1 &&
+	verify_no_mergehead &&
+	verify_diff squash.1-5 .git/SQUASH_MSG "[OOPS] bad squash message"
+'
+
+test_debug 'gitk --all'
+
+test_expect_success 'override config option -n' '
+	git reset --hard c1 &&
+	git config branch.master.mergeoptions "-n" &&
+	test_tick &&
+	git merge --summary c2 >diffstat.txt &&
+	verify_merge file result.1-5 msg.1-5 &&
+	verify_parents $c1 $c2 &&
+	if ! grep -e "^ file | \+2 +-$" diffstat.txt
+	then
+		echo "[OOPS] diffstat was not generated"
+	fi
+'
+
+test_debug 'gitk --all'
+
+test_expect_success 'override config option --summary' '
+	git reset --hard c1 &&
+	git config branch.master.mergeoptions "--summary" &&
+	test_tick &&
+	git merge -n c2 >diffstat.txt &&
+	verify_merge file result.1-5 msg.1-5 &&
+	verify_parents $c1 $c2 &&
+	if grep -e "^ file | \+2 +-$" diffstat.txt
+	then
+		echo "[OOPS] diffstat was generated"
+		false
+	fi
+'
+
+test_debug 'gitk --all'
+
 test_done