remote_get_heads: reference length limit

I've been having trouble with git push apparently resending the entire commit trace for the branch each and every time I push. Poking at the source it seems this is due to a length limit on reference names as pulled from the remote repository.

When we are building the pack to send we are sent a list of remote heads. get_remote_heads() reads these in, validates them and finally adds them to the remote_refs list. Part of the validation is a simple check for size and form; check_ref().

static int check_ref(const char *name, int len, unsigned int flags)
{
        if (!flags)
                return 1;

        if (len > 45 || memcmp(name, "refs/", 5))
                return 0;
[...]
}

With the refs/heads/ prefix included this limits the head names to 34 characters. From what I can see there is no good reason for this limit to be so low. I can see we don't want the remote end bloating us out of control, but we are already limiting the lines which contain these references to 1000 bytes and making no attempt to limit the number of them the remote server can send us. There seems to be no limits imposed on the name length other than MAX_PATHLEN.

Can anyone see a reason to keep this (len > 45) check?

-apw

send-pack: remove remote reference limit

When build a pack for a push we query the remote copy for existant heads. These are used to prune unnecessary objects from the pack. As we receive the remote references in get_remote_heads() we validate the reference names via check_ref() which includes a length check; rejecting those >45 characters in size.

We appear to be able to handle reference names upto MAXPATHLEN in size. Relax the limit out to that size.

Signed-off-by: Andy Whitcroft <apw@shadowen.org>
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