[PATCH 2] Add default merge options for all branches

[Michael Grubb <devel@dailyvoid.com>]

Add support for branch.*.mergeoptions for setting default options for
all branches.  This new value shares semantics with the existing
branch.<name>.mergeoptions variable. If a branch specific value is
found, that value will be used.

The need for this arises from the fact that there is currently not an
easy way to set merge options for all branches. Instead of having to
specify merge options for each individual branch there should be a way
to set defaults for all branches and then override a specific branch's
options.

The approach taken is to make note of whether a branch specific
mergeoptions key has been seen and only apply the global value if it
hasn't.

Signed-off-by: Michael Grubb <devel@dailyvoid.com>
---
 Documentation/git-merge.txt |    3 +++
 builtin/merge.c             |   27 ++++++++++++++++++++++-----
 t/t7600-merge.sh            |   27 +++++++++++++++++++++++++++
 3 files changed, 52 insertions(+), 5 deletions(-)

diff --git a/Documentation/git-merge.txt b/Documentation/git-merge.txt
index e2e6aba..eaab3e4 100644
--- a/Documentation/git-merge.txt
+++ b/Documentation/git-merge.txt
@@ -307,6 +307,9 @@ branch.<name>.mergeoptions::
 	Sets default options for merging into branch <name>. The syntax and
 	supported options are the same as those of 'git merge', but option
 	values containing whitespace characters are currently not supported.
+	The special value '*' for <name> may be used to configure default
+	options for all branches.  Values for specific branch names will
+	override the this default.
 
 SEE ALSO
 --------
diff --git a/builtin/merge.c b/builtin/merge.c
index 0bdd19a..9e5b6bd 100644
--- a/builtin/merge.c
+++ b/builtin/merge.c
@@ -505,9 +505,18 @@ cleanup:
 
 static int git_merge_config(const char *k, const char *v, void *cb)
 {
-	if (branch && !prefixcmp(k, "branch.") &&
-		!prefixcmp(k + 7, branch) &&
-		!strcmp(k + 7 + strlen(branch), ".mergeoptions")) {
+	static int branch_merge_options_set = 0;
+	int merge_option_mode = 0;
+
+	if (!strcmp(k, "branch.*.mergeoptions"))
+		merge_option_mode = 1;
+	else if (branch && !prefixcmp(k, "branch.") &&
+			 !prefixcmp(k + 7, branch) &&
+			 !strcmp(k + 7 + strlen(branch), ".mergeoptions"))
+		merge_option_mode = 2;
+
+	if ((merge_option_mode == 1 && !branch_merge_options_set) ||
+		  merge_option_mode == 2) {
 		const char **argv;
 		int argc;
 		char *buf;
@@ -515,14 +524,22 @@ static int git_merge_config(const char *k, const char *v, void *cb)
 		buf = xstrdup(v);
 		argc = split_cmdline(buf, &argv);
 		if (argc < 0)
-			die(_("Bad branch.%s.mergeoptions string: %s"), branch,
-			    split_cmdline_strerror(argc));
+		{
+			if (merge_option_mode == 1)
+				die(_("Bad merge.mergeoptions string: %s"), 
+					split_cmdline_strerror(argc));
+			else
+				die(_("Bad branch.%s.mergeoptions string: %s"), branch,
+					split_cmdline_strerror(argc));
+		}
 		argv = xrealloc(argv, sizeof(*argv) * (argc + 2));
 		memmove(argv + 1, argv, sizeof(*argv) * (argc + 1));
 		argc++;
 		parse_options(argc, argv, NULL, builtin_merge_options,
 			      builtin_merge_usage, 0);
 		free(buf);
+		if (merge_option_mode == 2)
+			branch_merge_options_set = 1;
 	}
 
 	if (!strcmp(k, "merge.diffstat") || !strcmp(k, "merge.stat"))
diff --git a/t/t7600-merge.sh b/t/t7600-merge.sh
index 87d5d78..bfb7348 100755
--- a/t/t7600-merge.sh
+++ b/t/t7600-merge.sh
@@ -415,6 +415,33 @@ test_expect_success 'merge c0 with c1 (no-ff)' '
 
 test_debug 'git log --graph --decorate --oneline --all'
 
+test_expect_success 'merge c0 with c1 (global no-ff)' '
+	git reset --hard c0 &&
+	git config --unset branch.master.mergeoptions &&
+	git config "branch.*.mergeoptions" "--no-ff" &&
+	test_tick &&
+	git merge c1 &&
+	git config --remove-section "branch.*" &&
+	verify_merge file result.1 &&
+	verify_parents $c0 $c1
+'
+
+test_debug 'git log --graph --decorate --oneline --all'
+
+test_expect_success 'combine merge.mergeoptions with branch.x.mergeoptions' '
+	git reset --hard c0 &&
+	git config --remove-section branch.master &&
+	git config "branch.*.mergeoptions" "--no-ff" &&
+	git config branch.master.mergeoptions "--ff" &&
+	test_tick &&
+	git merge c1 &&
+	git config --remove-section "branch.*" &&
+	verify_merge file result.1 &&
+	verify_parents "$c0"
+'
+
+test_debug 'git log --graph --decorate --oneline --all'
+
 test_expect_success 'combining --squash and --no-ff is refused' '
 	test_must_fail git merge --squash --no-ff c1 &&
 	test_must_fail git merge --no-ff --squash c1
-- 
1.7.5