Subject: [PATCH v2 3/4] merge-recursive: fix verbose output for multiple base trees

From: René Scharfe <[email-masked]>
Date: Sat, 13 Aug 2016 14:16:04 +0200

One of the indirect callers of make_virtual_commit() passes the result of
oid_to_hex() as the name, i.e. a pointer to a static buffer.  Since the
function uses that string pointer directly in building a struct
merge_remote_desc, multiple entries can end up sharing the same name
inadvertently.

Fix that by calling set_merge_remote_desc(), which creates a copy of the
string, instead of building the struct by hand.

Signed-off-by: Rene Scharfe <[email-masked]>
---
 merge-recursive.c          |  5 +----
 t/t3030-merge-recursive.sh | 18 ++++++++++++++++++
 2 files changed, 19 insertions(+), 4 deletions(-)

diff --git a/merge-recursive.c b/merge-recursive.c
index e5243c2..e349126 100644
--- a/merge-recursive.c
+++ b/merge-recursive.c
@@ -73,12 +73,9 @@ static struct tree *shift_tree_object(struct tree *one, struct tree *two,
 static struct commit *make_virtual_commit(struct tree *tree, const char *comment)
 {
 	struct commit *commit = alloc_commit_node();
-	struct merge_remote_desc *desc = xmalloc(sizeof(*desc));
 
-	desc->name = comment;
-	desc->obj = (struct object *)commit;
+	set_merge_remote_desc(commit, comment, (struct object *)commit);
 	commit->tree = tree;
-	commit->util = desc;
 	commit->object.parsed = 1;
 	return commit;
 }
diff --git a/t/t3030-merge-recursive.sh b/t/t3030-merge-recursive.sh
index f7b0e59..470f334 100755
--- a/t/t3030-merge-recursive.sh
+++ b/t/t3030-merge-recursive.sh
@@ -660,4 +660,22 @@ test_expect_success 'merging with triple rename across D/F conflict' '
 	git merge other
 '
 
+test_expect_success 'merge-recursive remembers the names of all base trees' '
+	git reset --hard HEAD &&
+
+	# more trees than static slots used by oid_to_hex()
+	for commit in $c0 $c2 $c4 $c5 $c6 $c7
+	do
+		git rev-parse "$commit^{tree}"
+	done >trees &&
+
+	# ignore the return code -- it only fails because the input is weird
+	test_must_fail git -c merge.verbosity=5 merge-recursive $(cat trees) -- $c1 $c3 >out &&
+
+	# merge-recursive prints in reverse order, but we do not care
+	sort <trees >expect &&
+	sed -n "s/^virtual //p" out | sort >actual &&
+	test_cmp expect actual
+'
+
 test_done
-- 
2.9.3