[RFC] Don't expect verify_pack() callers to set pack_size

[Mike Hommey <mh@glandium.org>]

Since use_pack() will end up populating pack_size if it is not already set,
we can just adapt the code in verify_packfile() such that it doesn't require
pack_size to be set beforehand.

This allows callers not to have to set pack_size themselves, and we can thus
revert changes from 1c23d794.
---

 I'd like some feedback on this change in pack-check.c, that help refactoring
 more efficiently the code in http-*.c.

 http-push.c   |    3 ---
 http-walker.c |    1 -
 pack-check.c  |    8 +++++---
 3 files changed, 5 insertions(+), 7 deletions(-)

diff --git a/http-push.c b/http-push.c
index b2b410d..be54ed3 100644
--- a/http-push.c
+++ b/http-push.c
@@ -770,14 +770,11 @@ static void finish_request(struct transfer_request *request)
 				request->url, curl_errorstr);
 			remote->can_update_info_refs = 0;
 		} else {
-			off_t pack_size = ftell(request->local_stream);
-
 			fclose(request->local_stream);
 			request->local_stream = NULL;
 			if (!move_temp_to_file(request->tmpfile,
 					       request->filename)) {
 				target = (struct packed_git *)request->userData;
-				target->pack_size = pack_size;
 				lst = &remote->packs;
 				while (*lst != target)
 					lst = &((*lst)->next);
diff --git a/http-walker.c b/http-walker.c
index 2c37868..29f9728 100644
--- a/http-walker.c
+++ b/http-walker.c
@@ -783,7 +783,6 @@ static int fetch_pack(struct walker *walker, struct alt_base *repo, unsigned cha
 		return error("Unable to start request");
 	}
 
-	target->pack_size = ftell(packfile);
 	fclose(packfile);
 
 	ret = move_temp_to_file(tmpfile, filename);
diff --git a/pack-check.c b/pack-check.c
index d7dd62b..e7f0126 100644
--- a/pack-check.c
+++ b/pack-check.c
@@ -25,7 +25,7 @@ static int verify_packfile(struct packed_git *p,
 	const unsigned char *index_base = p->index_data;
 	SHA_CTX ctx;
 	unsigned char sha1[20];
-	off_t offset = 0, pack_sig = p->pack_size - 20;
+	off_t offset = 0, pack_sig = 0;
 	uint32_t nr_objects, i;
 	int err;
 	struct idx_entry *entries;
@@ -37,14 +37,16 @@ static int verify_packfile(struct packed_git *p,
 	 */
 
 	SHA1_Init(&ctx);
-	while (offset < pack_sig) {
+	do {
 		unsigned int remaining;
 		unsigned char *in = use_pack(p, w_curs, offset, &remaining);
 		offset += remaining;
+		if (pack_sig == 0)
+			pack_sig = p->pack_size - 20;
 		if (offset > pack_sig)
 			remaining -= (unsigned int)(offset - pack_sig);
 		SHA1_Update(&ctx, in, remaining);
-	}
+	} while (offset < pack_sig);
 	SHA1_Final(sha1, &ctx);
 	if (hashcmp(sha1, use_pack(p, w_curs, pack_sig, NULL)))
 		return error("Packfile %s SHA1 mismatch with itself",
-- 
1.5.4.rc5.12.gb8680-dirty