Re: [PATCH 4/3] t3700: avoid racy git situation

[Johannes Schindelin <Johannes.Schindelin@gmx.de>]

Hi,

On Thu, 8 Nov 2007, Johannes Sixt wrote:

> Johannes Schindelin schrieb:
> > Wow, the builtin commit is fast.  It sometimes triggers a racy
> > situation in the test case for "git add --refresh -- foo".
> > 
> > So when that test fails, simply sleep one second and try again.
> 
> [/me looks at the calender - no, it's not April Fool's day]

No. The builtin commit is really that fast.

> Wouldn't it be better to fix git-commit (or git-add)? I would like to 
> help, but you already seem to have done the analysis, so...

The problem is that the index has the same timestamp as the file "foo".

Therefore, git cannot tell if "foo" is up-to-date in the index, since it 
could have been modified (and indeed is) just a fraction of a second later 
than the index was last updated.

And since diff-index, as called from the test script, does not generate a 
diff, but really only determines if the index information suggests that 
the files are up-to-date, there is not really much you can do.

This is our good old friend, the racy git problem.

NOTE: other scms do not have this problem, mostly because they are too 
slow to trigger it.

Ciao,
Dscho