Re: [PATCH] fsck: check skiplist for object in fsck_blob()

From: Jeff King <peff@peff.net>
Date: Jun 28, 2018, 22:03 UTC
Message-ID: <20180628220332.GA5128@sigill.intra.peff.net>
In-Reply-To: <db7683ab-1025-d7bb-d0ce-fc4ee28681e1@ramsayjones.plus.com>

On Thu, Jun 28, 2018 at 07:53:27PM +0100, Ramsay Jones wrote:

Show 8 quoted lines

> > Yes, though I don't think it's too bad. We already have a "die_on_error"
> > flag in the config code. I think it just needs to become a tristate:
> > die/error/silent (and probably get passed in via config_options, since I
> > think we tie it right now to the file/blob source).
> 
> Yes, but this code is already very crufty - and I'm just
> waiting for someone to want to have per-repo/submodule
> config parsing i... ;-)

It is crufty, but I think we actually handle that part OK; the flag gets attached to the stack.

Show 8 quoted lines

> > Hmm, if we end up doing the config thing above, then this patch would
> > become unnecessary.
> 
> I was thinking of timing - the current patch could go
> in quickly to solve the immediate problem (eg. in maint).
> 
> Also, it does not hurt to do this _as well as_ suppress
> the config errors.

Yes, it can go in quickly. But I'd prefer not to keep it in the long term if it's literally doing nothing.

I have some patches which I think solve your problem. They apply on v2.18.0, but not on v2.17.1 (because they rely on Dscho's increased passing of config_options in v2.18). Is that good enough?

Show 15 quoted lines

> > And I think doing that would help _all_ cases, even ones without a
> > skiplist. They don't need to see random config error messages either,
> > even if we do eventually report an fsck error.
> 
> Oh, yes, I agree. You will have noticed that it was my
> first suggested solution. (I have started writing that
> patch a few times, but it just makes me want to throw
> the current code away and start again)!
> 
> Hmm, BTW, the 'rejected push' problem would include *any*
> '.gitmodules' blob that contained a syntax error, right?
> 
> Maybe it won't be as rare as all that! (Imagine not being
> able to push due to a compiler error/warning in source files.
> How irritating would that be! :-P ).

Yes, it would include any syntax error. I also have a slight worry about that, but nobody seems to have screamed _yet_. :)

> (if we fix this, you could hide some nefarious settings
> after an obvious syntax error - then get the victim to
> fix the syntax error ...)

You can also usually get the victim to type "make", which is even simpler. :)

Here are the patches I came up with.

Note that the config_options struct has a bit of a dual-nature. Some options are respected only via config_from_options(), and some only from git_config_from_file(). I think this should probably be remedied in the long run, but I stopped here in the interest of keeping this maint-worthy.

  [1/4]: config: turn die_on_error into caller-facing enum
  [2/4]: config: add CONFIG_ERROR_SILENT handler
  [3/4]: config: add options parameter to git_config_from_mem
  [4/4]: fsck: silence stderr when parsing .gitmodules

 config.c                   | 32 +++++++++++++++++++++++---------
 config.h                   | 13 +++++++++++--
 fsck.c                     |  4 +++-
 submodule-config.c         |  2 +-
 t/t7415-submodule-names.sh | 15 +++++++++++++++
 5 files changed, 53 insertions(+), 13 deletions(-)

-Peff