patchbuiltin-rerere: fix conflict markers parsing

builtin-rerere.c, t/t4200-rerere.sh

diff --git a/builtin-rerere.c b/builtin-rerere.c
index 839b26e..e618862 100644
--- a/builtin-rerere.c
+++ b/builtin-rerere.c
@@ -112,11 +112,12 @@ static int handle_file(const char *path,
 	strbuf_init(&one, 0);
 	strbuf_init(&two,  0);
 	while (fgets(buf, sizeof(buf), f)) {
-		if (!prefixcmp(buf, "<<<<<<< "))
+		if (hunk == 0 && !prefixcmp(buf, "<<<<<<< "))
 			hunk = 1;
-		else if (!prefixcmp(buf, "======="))
+		else if (hunk == 1 && !prefixcmp(buf, "=======") &&
+			 isspace(buf[7]))
 			hunk = 2;
-		else if (!prefixcmp(buf, ">>>>>>> ")) {
+		else if (hunk == 2 && !prefixcmp(buf, ">>>>>>> ")) {
 			if (strbuf_cmp(&one, &two) > 0)
 				strbuf_swap(&one, &two);
 			hunk_no++;
diff --git a/t/t4200-rerere.sh b/t/t4200-rerere.sh
index a64727d..cf10557 100755
--- a/t/t4200-rerere.sh
+++ b/t/t4200-rerere.sh
@@ -9,6 +9,8 @@ test_description='git rerere
 . ./test-lib.sh
 
 cat > a1 << EOF
+Some title
+==========
 Whether 'tis nobler in the mind to suffer
 The slings and arrows of outrageous fortune,
 Or to take arms against a sea of troubles,
@@ -24,6 +26,8 @@ git commit -q -a -m initial
 
 git checkout -b first
 cat >> a1 << EOF
+Some title
+==========
 To die, to sleep;
 To sleep: perchance to dream: ay, there's the rub;
 For in that sleep of death what dreams may come
@@ -35,7 +39,7 @@ git commit -q -a -m first
 
 git checkout -b second master
 git show first:a1 |
-sed -e 's/To die, t/To die! T/' > a1
+sed -e 's/To die, t/To die! T/' -e 's/Some title/Some Title/' > a1
 echo "* END *" >>a1
 git commit -q -a -m second
 
@@ -55,14 +59,14 @@ test_expect_success 'conflicting merge' '
 
 sha1=$(sed -e 's/	.*//' .git/rr-cache/MERGE_RR)
 rr=.git/rr-cache/$sha1
-test_expect_success 'recorded preimage' "grep ======= $rr/preimage"
+test_expect_success 'recorded preimage' "grep ^=======$ $rr/preimage"
 
 test_expect_success 'rerere.enabled works, too' '
 	rm -rf .git/rr-cache &&
 	git config rerere.enabled true &&
 	git reset --hard &&
 	! git merge first &&
-	grep ======= $rr/preimage
+	grep ^=======$ $rr/preimage
 '
 
 test_expect_success 'no postimage or thisimage yet' \
@@ -71,7 +75,7 @@ test_expect_success 'no postimage or thisimage yet' \
 test_expect_success 'preimage has right number of lines' '
 
 	cnt=$(sed -ne "/^<<<<<<</,/^>>>>>>>/p" $rr/preimage | wc -l) &&
-	test $cnt = 9
+	test $cnt = 13
 
 '
 
@@ -80,13 +84,23 @@ git show first:a1 > a1
 cat > expect << EOF
 --- a/a1
 +++ b/a1
-@@ -6,17 +6,9 @@
+@@ -1,4 +1,4 @@
+-Some Title
++Some title
+ ==========
+ Whether 'tis nobler in the mind to suffer
+ The slings and arrows of outrageous fortune,
+@@ -8,21 +8,11 @@
  The heart-ache and the thousand natural shocks
  That flesh is heir to, 'tis a consummation
  Devoutly to be wish'd.
 -<<<<<<<
+-Some Title
+-==========
 -To die! To sleep;
 -=======
+ Some title
+ ==========
  To die, to sleep;
 ->>>>>>>
  To sleep: perchance to dream: ay, there's the rub;
@@ -124,7 +138,7 @@ test_expect_success 'another conflicting merge' '
 '
 
 git show first:a1 | sed 's/To die: t/To die! T/' > expect
-test_expect_success 'rerere kicked in' "! grep ======= a1"
+test_expect_success 'rerere kicked in' "! grep ^=======$ a1"
 
 test_expect_success 'rerere prefers first change' 'test_cmp a1 expect'
 

diff --git a/builtin-rerere.c b/builtin-rerere.c
index e618862..69c3a52 100644
--- a/builtin-rerere.c
+++ b/builtin-rerere.c
@@ -112,12 +112,17 @@ static int handle_file(const char *path,
 	strbuf_init(&one, 0);
 	strbuf_init(&two,  0);
 	while (fgets(buf, sizeof(buf), f)) {
-		if (hunk == 0 && !prefixcmp(buf, "<<<<<<< "))
+		if (!prefixcmp(buf, "<<<<<<< ")) {
+			if (hunk)
+				goto bad;
 			hunk = 1;
-		else if (hunk == 1 && !prefixcmp(buf, "=======") &&
-			 isspace(buf[7]))
+		} else if (!prefixcmp(buf, "=======") && isspace(buf[7])) {
+			if (hunk != 1)
+				goto bad;
 			hunk = 2;
-		else if (hunk == 2 && !prefixcmp(buf, ">>>>>>> ")) {
+		} else if (!prefixcmp(buf, ">>>>>>> ")) {
+			if (hunk != 2)
+				goto bad;
 			if (strbuf_cmp(&one, &two) > 0)
 				strbuf_swap(&one, &two);
 			hunk_no++;
@@ -143,6 +148,10 @@ static int handle_file(const char *path,
 			strbuf_addstr(&two, buf);
 		else if (out)
 			fputs(buf, out);
+		continue;
+	bad:
+		hunk = 99; /* force error exit */
+		break;
 	}
 	strbuf_release(&one);
 	strbuf_release(&two);