From: Junio C Hamano <gitster@pobox.com>
Date: Mon, 24 Sep 2018 17:30:48 +0000 (-0700)
Subject: Merge branch 'en/rerere-multi-stage-1-fix'
X-Git-Tag: v2.20.0-rc0~217
X-Git-Url: https://git.lorimer.id.au/gitweb.git/diff_plain/bd3941a0aed0756aba43f504d0dea7a3fbe0c82b?hp=e3d4ff037db41234eaf74167ab7d1a443c23243d

Merge branch 'en/rerere-multi-stage-1-fix'

A corner case bugfix in "git rerere" code.

* en/rerere-multi-stage-1-fix:
rerere: avoid buffer overrun
t4200: demonstrate rerere segfault on specially crafted merge
---

diff --git a/rerere.c b/rerere.c
index 2fd3181f7b..7aa149e849 100644
--- a/rerere.c
+++ b/rerere.c
@@ -521,7 +521,7 @@ static int check_one_conflict(int i, int *type)
 	}
 
 	*type = PUNTED;
-	while (ce_stage(active_cache[i]) == 1)
+	while (i < active_nr && ce_stage(active_cache[i]) == 1)
 		i++;
 
 	/* Only handle regular files with both stages #2 and #3 */
diff --git a/t/t4200-rerere.sh b/t/t4200-rerere.sh
index 428b3c1e9e..55b7750ade 100755
--- a/t/t4200-rerere.sh
+++ b/t/t4200-rerere.sh
@@ -642,4 +642,33 @@ test_expect_success 'rerere with inner conflict markers' '
 	test_cmp expect actual
 '
 
+test_expect_success 'setup simple stage 1 handling' '
+	test_create_repo stage_1_handling &&
+	(
+		cd stage_1_handling &&
+
+		test_seq 1 10 >original &&
+		git add original &&
+		git commit -m original &&
+
+		git checkout -b A master &&
+		git mv original A &&
+		git commit -m "rename to A" &&
+
+		git checkout -b B master &&
+		git mv original B &&
+		git commit -m "rename to B"
+	)
+'
+
+test_expect_success 'test simple stage 1 handling' '
+	(
+		cd stage_1_handling &&
+
+		git config rerere.enabled true &&
+		git checkout A^0 &&
+		test_must_fail git merge B^0
+	)
+'
+
 test_done