git notes merge: List conflicting notes in notes merge commit message

This brings notes merge in line with regular merge's behaviour.

This patch has been improved by the following contributions:
- Ævar Arnfjörð Bjarmason: Don't use C99 comments.

Thanks-to: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: Johan Herland <johan@herland.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

4 files changed, 24 insertions, 3 deletions

diff --git a/builtin/notes.c b/builtin/notes.c
index b5385238ea..ee1df7030c 100644
--- a/builtin/notes.c
+++ b/builtin/notes.c
@@ -902,7 +902,7 @@ static int merge(int argc, const char **argv, const char *prefix)
 
 	strbuf_addf(&msg, "notes: Merged notes from %s into %s",
 		    remote_ref.buf, default_notes_ref());
-	o.commit_msg = msg.buf + 7; // skip "notes: " prefix
+	strbuf_add(&(o.commit_msg), msg.buf + 7, msg.len - 7); /* skip "notes: " */
 
 	result = notes_merge(&o, t, result_sha1);
 
diff --git a/notes-merge.c b/notes-merge.c
index a2feab6d1b..459b1c2bf2 100644
--- a/notes-merge.c
+++ b/notes-merge.c
@@ -8,6 +8,7 @@
 #include "dir.h"
 #include "notes.h"
 #include "notes-merge.h"
+#include "strbuf.h"
 
 struct notes_merge_pair {
 	unsigned char obj[20], base[20], local[20], remote[20];
@@ -16,6 +17,7 @@ struct notes_merge_pair {
 void init_notes_merge_options(struct notes_merge_options *o)
 {
 	memset(o, 0, sizeof(struct notes_merge_options));
+	strbuf_init(&(o->commit_msg), 0);
 	o->verbosity = NOTES_MERGE_VERBOSITY_DEFAULT;
 }
 
@@ -384,6 +386,12 @@ static int merge_one_change_manual(struct notes_merge_options *o,
 	       sha1_to_hex(p->obj), sha1_to_hex(p->base),
 	       sha1_to_hex(p->local), sha1_to_hex(p->remote));
 
+	/* add "Conflicts:" section to commit message first time through */
+	if (!o->has_worktree)
+		strbuf_addstr(&(o->commit_msg), "\n\nConflicts:\n");
+
+	strbuf_addf(&(o->commit_msg), "\t%s\n", sha1_to_hex(p->obj));
+
 	OUTPUT(o, 2, "Auto-merging notes for %s", sha1_to_hex(p->obj));
 	check_notes_merge_worktree(o);
 	if (is_null_sha1(p->local)) {
@@ -640,12 +648,13 @@ int notes_merge(struct notes_merge_options *o,
 		struct commit_list *parents = NULL;
 		commit_list_insert(remote, &parents); /* LIFO order */
 		commit_list_insert(local, &parents);
-		create_notes_commit(local_tree, parents, o->commit_msg,
+		create_notes_commit(local_tree, parents, o->commit_msg.buf,
 				    result_sha1);
 	}
 
 found_result:
 	free_commit_list(bases);
+	strbuf_release(&(o->commit_msg));
 	trace_printf("notes_merge(): result = %i, result_sha1 = %.7s\n",
 	       result, sha1_to_hex(result_sha1));
 	return result;
diff --git a/notes-merge.h b/notes-merge.h
index aa756931a5..195222f9da 100644
--- a/notes-merge.h
+++ b/notes-merge.h
@@ -11,7 +11,7 @@ enum notes_merge_verbosity {
 struct notes_merge_options {
 	const char *local_ref;
 	const char *remote_ref;
-	const char *commit_msg;
+	struct strbuf commit_msg;
 	int verbosity;
 	enum {
 		NOTES_MERGE_RESOLVE_MANUAL = 0,
diff --git a/t/t3310-notes-merge-manual-resolve.sh b/t/t3310-notes-merge-manual-resolve.sh
index 0ec315aa9b..287fab82d7 100755
--- a/t/t3310-notes-merge-manual-resolve.sh
+++ b/t/t3310-notes-merge-manual-resolve.sh
@@ -333,6 +333,12 @@ EOF
 	git log -1 --format=%B refs/notes/m > merge_commit_msg &&
 	grep -q refs/notes/m merge_commit_msg &&
 	grep -q refs/notes/z merge_commit_msg &&
+	# Merge commit mentions conflicting notes
+	grep -q "Conflicts" merge_commit_msg &&
+	( for sha1 in $(cat expect_conflicts); do
+		grep -q "$sha1" merge_commit_msg ||
+		exit 1
+	done ) &&
 	# Verify contents of merge result
 	verify_notes m &&
 	# Verify that other notes refs has not changed (w, x, y and z)
@@ -456,6 +462,12 @@ EOF
 	git log -1 --format=%B refs/notes/m > merge_commit_msg &&
 	grep -q refs/notes/m merge_commit_msg &&
 	grep -q refs/notes/z merge_commit_msg &&
+	# Merge commit mentions conflicting notes
+	grep -q "Conflicts" merge_commit_msg &&
+	( for sha1 in $(cat expect_conflicts); do
+		grep -q "$sha1" merge_commit_msg ||
+		exit 1
+	done ) &&
 	# Verify contents of merge result
 	verify_notes m &&
 	# Verify that other notes refs has not changed (w, x, y and z)