Re: Crashes while trying to show tag objects with bad timestamps

[Jeff King <peff@peff.net>]

On Sat, Feb 23, 2013 at 01:14:40AM +0200, Mantas Mikulėnas wrote:

> > Then I think it would make sense to allow the very specific no-date tag,
> > but not allow arbitrary crud. I wonder if there's an example in the
> > kernel or in git.git.
> 
> I couldn't find any such examples. However, I did find several tags
> with no "tagger" line at all: git.git has "v0.99" and linux.git has
> many such tags starting with "v2.6.11" ending with "v2.6.13-rc3".

Yes, I think Junio was mis-remembering the exact condition. It looks
like we added tagger lines in c818566 ([PATCH] Update tags to record who
made them, 2005-07-14), which pulls the identity straight from "git var
GIT_COMMITTER_IDENT". I double-checked to be sure that we included the
date stamp at that time, and we did.

When parsing such a tag, we put a "0" in the date field of the "struct
tag", and I suspect that is what caused the memory confusion.

So I think we are fine to fsck tagger lines as we do ordinary
author/committer ident lines; the only exception is that we should not
complain if they do not exist.

> It seems that `git cat-file -p` doesn't like such tags too – if there
> is no "tagger", it doesn't display *any* header lines. More bugs?

Yeah, I think we should just rid of that parser entirely. It is very
inconsistent with the pretty-printer used by "git show", as well as the
one used by "git for-each-ref", not to mention parse_tag (ugh, how many
tag parsers do we have?).

-Peff