send-pack: do not give up when remote has insanely large number of refs.

Stephen C. Tweedie noticed that we give up running rev-list when
we see too many refs on the remote side.  Limit the number of
negative references we give to rev-list and continue.

Not sending any negative references to rev-list is very bad --
we may be pushing a ref that is new to the other end.

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

diff --git a/send-pack.c b/send-pack.c
index 990be3f..b58bbab 100644 (file)
--- a/send-pack.c
+++ b/send-pack.c
@@ -37,26 +37,44 @@ static void exec_pack_objects(void)
 
 static void exec_rev_list(struct ref *refs)
 {
+       struct ref *ref;
        static char *args[1000];
-       int i = 0;
+       int i = 0, j;
 
        args[i++] = "rev-list"; /* 0 */
        args[i++] = "--objects";        /* 1 */
-       while (refs) {
-               char *buf = malloc(100);
-               if (i > 900)
+
+       /* First send the ones we care about most */
+       for (ref = refs; ref; ref = ref->next) {
+               if (900 < i)
                        die("git-rev-list environment overflow");
-               if (!is_zero_sha1(refs->old_sha1) &&
-                   has_sha1_file(refs->old_sha1)) {
+               if (!is_zero_sha1(ref->new_sha1)) {
+                       char *buf = malloc(100);
                        args[i++] = buf;
-                       snprintf(buf, 50, "^%s", sha1_to_hex(refs->old_sha1));
+                       snprintf(buf, 50, "%s", sha1_to_hex(ref->new_sha1));
                        buf += 50;
+                       if (!is_zero_sha1(ref->old_sha1) &&
+                           has_sha1_file(ref->old_sha1)) {
+                               args[i++] = buf;
+                               snprintf(buf, 50, "^%s",
+                                        sha1_to_hex(ref->old_sha1));
+                       }
                }
-               if (!is_zero_sha1(refs->new_sha1)) {
+       }
+
+       /* Then a handful of the remainder
+        * NEEDSWORK: we would be better off if used the newer ones first.
+        */
+       for (ref = refs, j = i + 16;
+            i < 900 && i < j && ref;
+            ref = ref->next) {
+               if (is_zero_sha1(ref->new_sha1) &&
+                   !is_zero_sha1(ref->old_sha1) &&
+                   has_sha1_file(ref->old_sha1)) {
+                       char *buf = malloc(42);
                        args[i++] = buf;
-                       snprintf(buf, 50, "%s", sha1_to_hex(refs->new_sha1));
+                       snprintf(buf, 42, "^%s", sha1_to_hex(ref->old_sha1));
                }
-               refs = refs->next;
        }
        args[i] = NULL;
        execv_git_cmd(args);