Re: [PATCH] diffcore: fix iteration order of identical files during rename detection

Reported-by: Bill Okara <redacted>
Signed-off-by: SZEDER Gábor <redacted>
---

Resend of the patch, with a slightly updated commit message, included
in

  http://thread.gmane.org/gmane.comp.version-control.git/287281/focus=287570

Being embedded with scissors in an email without Junio among the
recipients on the day the first -rc was tagged...  no wonder it flew
below the radar.

 diffcore-rename.c      |  6 ++++--
 t/t4001-diff-rename.sh | 11 +++++++++++
 2 files changed, 15 insertions(+), 2 deletions(-)

diff --git a/diffcore-rename.c b/diffcore-rename.c
index 3b3c1ed535e7..7f03eb5a0404 100644
--- a/diffcore-rename.c
+++ b/diffcore-rename.c

@@ -340,9 +340,11 @@ static int find_exact_renames(struct diff_options *options)
 	int i, renames = 0;
 	struct hashmap file_table;
 
-	/* Add all sources to the hash table */
+	/* Add all sources to the hash table in reverse order, because
+	 * later on they will be retrieved in LIFO order.
+	 */
 	hashmap_init(&file_table, NULL, rename_src_nr);
-	for (i = 0; i < rename_src_nr; i++)
+	for (i = rename_src_nr-1; i >= 0; i--)
 		insert_file_table(&file_table, i, rename_src[i].p->one);
 
 	/* Walk the destinations and find best source match */

diff --git a/t/t4001-diff-rename.sh b/t/t4001-diff-rename.sh
index 2f327b749588..ed90c6c6f984 100755
--- a/t/t4001-diff-rename.sh
+++ b/t/t4001-diff-rename.sh

@@ -77,6 +77,17 @@ test_expect_success 'favour same basenames even with minor differences' '
 	git show HEAD:path1 | sed "s/15/16/" > subdir/path1 &&
 	git status | test_i18ngrep "renamed: .*path1 -> subdir/path1"'
 
+test_expect_success 'two files with same basename and same content' '
+	git reset --hard &&
+	mkdir -p dir/A dir/B &&
+	cp path1 dir/A/file &&
+	cp path1 dir/B/file &&
+	git add dir &&
+	git commit -m 2 &&
+	git mv dir other-dir &&
+	git status | test_i18ngrep "renamed: .*dir/A/file -> other-dir/A/file"
+'
+
 test_expect_success 'setup for many rename source candidates' '
 	git reset --hard &&
 	for i in 0 1 2 3 4 5 6 7 8 9;