Merge branch 'do/maint-merge-recursive-fix' into maint

* do/maint-merge-recursive-fix:
  merge-recursive: never leave index unmerged while recursing

Author: gitster

merge-recursive.c

@@ -933,11 +933,12 @@ static int process_renames(struct merge_options *o,
 				       ren1_src, ren1_dst, branch1,
 				       branch2);
 				update_file(o, 0, ren1->pair->two->sha1, ren1->pair->two->mode, ren1_dst);
-				update_stages(ren1_dst, NULL,
-						branch1 == o->branch1 ?
-						ren1->pair->two : NULL,
-						branch1 == o->branch1 ?
-						NULL : ren1->pair->two, 1);
+				if (!o->call_depth)
+					update_stages(ren1_dst, NULL,
+							branch1 == o->branch1 ?
+							ren1->pair->two : NULL,
+							branch1 == o->branch1 ?
+							NULL : ren1->pair->two, 1);
 			} else if (!sha_eq(dst_other.sha1, null_sha1)) {
 				const char *new_path;
 				clean_merge = 0;

t/t3031-merge-criscross.sh

@@ -0,0 +1,95 @@
+#!/bin/sh
+
+test_description='merge-recursive backend test'
+
+. ./test-lib.sh
+
+#         A      <- create some files
+#        / \
+#       B   C    <- cause rename/delete conflicts between B and C
+#      /     \
+#     |\     /|
+#     | D   E |
+#     |  \ /  |
+#     |   X   |
+#     |  / \  |
+#     | /   \ |
+#     |/     \|
+#     F       G  <- merge E into B, D into C
+#      \     /
+#       \   /
+#        \ /
+#         H      <- recursive merge crashes
+#
+
+# initialize
+test_expect_success 'setup repo with criss-cross history' '
+	mkdir data &&
+
+	# create a bunch of files
+	n=1 &&
+	while test $n -le 10
+	do
+		echo $n > data/$n &&
+		n=$(($n+1)) ||
+		break
+	done &&
+
+	# check them in
+	git add data &&
+	git commit -m A &&
+	git branch A &&
+
+	# a file in one branch
+	git checkout -b B A &&
+	git rm data/9 &&
+	git add data &&
+	git commit -m B &&
+
+	# with a branch off of it
+	git branch D &&
+
+	# put some commits on D
+	git checkout D &&
+	echo testD > data/testD &&
+	git add data &&
+	git commit -m D &&
+
+	# back up to the top, create another branch and cause
+	# a rename conflict with the file we deleted earlier
+	git checkout -b C A &&
+	git mv data/9 data/new-9 &&
+	git add data &&
+	git commit -m C &&
+
+	# with a branch off of it
+	git branch E &&
+
+	# put a commit on E
+	git checkout E &&
+	echo testE > data/testE &&
+	git add data &&
+	git commit -m E &&
+
+	# now, merge E into B
+	git checkout B &&
+	test_must_fail git merge E &&
+	# force-resolve
+	git add data &&
+	git commit -m F &&
+	git branch F &&
+
+	# and merge D into C
+	git checkout C &&
+	test_must_fail git merge D &&
+	# force-resolve
+	git add data &&
+	git commit -m G &&
+	git branch G
+'
+
+test_expect_success 'recursive merge between F and G, causes segfault' '
+	git merge F
+'
+
+test_done