upload-pack: Do not choke on too many heads request.

Cloning from a repository with more than 256 refs (heads and tags
included) will choke, because upload-pack has a built-in limit of
feeding not more than MAX_NEEDS (currently 256) heads to underlying
git-rev-list.  This is a problem when cloning a repository with many
tags, like http://www.linux-mips.org/pub/scm/linux.git, which has 290+
tags.

This commit introduces a new flag, --all, to git-rev-list, to include
all refs in the repository.  Updated upload-pack detects requests that
ask more than MAX_NEEDS refs, and sends everything back instead.

We may probably want to tweak the definitions of MAX_NEEDS and
MAX_HAS, but that is a separate topic.

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

1 files changed, 21 insertions, 0 deletions

diff --git a/rev-list.c b/rev-list.c
index 5ec9ccb60..c60aa7295 100644
--- a/rev-list.c
+++ b/rev-list.c
@@ -1,4 +1,5 @@
 #include "cache.h"
+#include "refs.h"
 #include "tag.h"
 #include "commit.h"
 #include "tree.h"
@@ -489,6 +490,22 @@ static void handle_one_commit(struct commit *com, struct commit_list **lst)
 	commit_list_insert(com, lst);
 }
 
+/* for_each_ref() callback does not allow user data -- Yuck. */
+static struct commit_list **global_lst;
+
+static int include_one_commit(const char *path, const unsigned char *sha1)
+{
+	struct commit *com = get_commit_reference(path, 0);
+	handle_one_commit(com, global_lst);
+	return 0;
+}
+
+static void handle_all(struct commit_list **lst)
+{
+	global_lst = lst;
+	for_each_ref(include_one_commit);
+	global_lst = NULL;
+}
 
 int main(int argc, char **argv)
 {
@@ -542,6 +559,10 @@ int main(int argc, char **argv)
 			bisect_list = 1;
 			continue;
 		}
+		if (!strcmp(arg, "--all")) {
+			handle_all(&list);
+			continue;
+		}
 		if (!strcmp(arg, "--objects")) {
 			tag_objects = 1;
 			tree_objects = 1;