rerere: make sorting really stable.

The earlier code does not swap hunks when the beginning of the
first side is identical to the whole of the second side.  In
such a case, the first one should sort later.

Signed-off-by: Junio C Hamano <junkio@cox.net>

diff --git a/builtin-rerere.c b/builtin-rerere.c
index b463c07f04b127ee3d1e17962813367fb4a5a588..8c2c8bdc18a69e4dff7386548e5f7ea78a133f7b 100644 (file)
--- a/builtin-rerere.c
+++ b/builtin-rerere.c
@@ -117,10 +117,13 @@ static int handle_file(const char *path,
                else if (!prefixcmp(buf, "======="))
                        hunk = 2;
                else if (!prefixcmp(buf, ">>>>>>> ")) {
+                       int one_is_longer = (one->nr > two->nr);
+                       int common_len = one_is_longer ? two->nr : one->nr;
+                       int cmp = memcmp(one->ptr, two->ptr, common_len);
+
                        hunk_no++;
                        hunk = 0;
-                       if (memcmp(one->ptr, two->ptr, one->nr < two->nr ?
-                                               one->nr : two->nr) > 0) {
+                       if ((cmp > 0) || ((cmp == 0) && one_is_longer)) {
                                struct buffer *swap = one;
                                one = two;
                                two = swap;

diff --git a/t/t4200-rerere.sh b/t/t4200-rerere.sh
index bc878d750dd526b38220bb6ab040c793946805a7..6ba63d7173ba5d333d80c017c4ef5a8c77b90a11 100755 (executable)
--- a/t/t4200-rerere.sh
+++ b/t/t4200-rerere.sh
@@ -35,7 +35,8 @@ git commit -q -a -m first
 
 git checkout -b second master
 git show first:a1 |
-sed -e 's/To die, t/To die! T/' -e 's/life;$/life./' > a1
+sed -e 's/To die, t/To die! T/' > a1
+echo "* END *" >>a1
 git commit -q -a -m second
 
 # activate rerere
@@ -53,7 +54,7 @@ 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 = 10
+       test $cnt = 9
 
 '
 
@@ -75,10 +76,10 @@ cat > expect << EOF
  For in that sleep of death what dreams may come
  When we have shuffled off this mortal coil,
  Must give us pause: there's the respect
+ That makes calamity of so long life;
 -<<<<<<<
--That makes calamity of so long life.
 -=======
- That makes calamity of so long life;
+-* END *
 ->>>>>>>
 EOF
 git rerere diff > out