Re: [PATCH 2/2] git: continue alias lookup on EACCES errors

From: Jeff King <peff@peff.net>
Date: Mar 28, 2012, 22:07 UTC
Message-ID: <20120328220731.GC10795@sigill.intra.peff.net>
In-Reply-To: <20120328215704.GB10795@sigill.intra.peff.net>

On Wed, Mar 28, 2012 at 05:57:04PM -0400, Jeff King wrote:

Show 7 quoted lines

> +static int exists_in_PATH(const char *file)
> +{
> +	const char *p = getenv("PATH");
> +	struct strbuf buf = STRBUF_INIT;
> +
> +	if (!p || !*p)
> +		return 0;

One thing to note: real execvp, when it sees a NULL $PATH, will fill in some OS-dependent default path. My linux box has _PATH_DEFPATH, but I don't know how portable that is (I can't find anything useful in POSIX).

> No tests yet. I'll post some output on that in a minute.

So here is a quick test script to show the output for a couple different cases. Should this be a real test script? A lot of what is being tested is the actual stderr output in many cases, which we tend to try not to include in tests.

-- >8 -- #!/bin/sh

rm -rf bin .git

# bin/broken is a PATH directory that cannot be searched # bin/ok can be searched, but has a broken entry mkdir bin bin/broken bin/ok chmod -x bin/broken

# The "yes" command lets us know when things are working. cat >bin/ok/git-yes <<\EOF #!/bin/sh echo yes EOF chmod +x bin/ok/git-yes

# and the "no" command is broken, and should be reported as EACCES
 >bin/ok/git-no

git init -q git config alias.alias-yes yes git config alias.alias-no no

PATH=$PWD/bin/broken:$PWD/bin/ok:$PATH

set -x git does-not-exist git yes git no git alias-yes git alias-no

-- >8 --

The output I get is:

# stock git
+ git does-not-exist
fatal: cannot exec 'git-does-not-exist': Permission denied
+ git yes
yes
+ git no
fatal: cannot exec 'git-no': Permission denied
+ git alias-yes
fatal: cannot exec 'git-alias-yes': Permission denied
+ git alias-no
fatal: cannot exec 'git-alias-no': Permission denied

# my earlier patches to do alias lookup after EACCES
+ git does-not-exist
Failed to run command 'does-not-exist': Permission denied
+ git yes
yes
+ git no
Failed to run command 'no': Permission denied
+ git alias-yes
yes
+ git alias-no
Expansion of alias 'alias-no' failed; 'no': Permission denied

# this patch
+ git does-not-exist
git: 'does-not-exist' is not a git command. See 'git --help'.
+ git yes
yes
+ git no
fatal: cannot exec 'git-no': Permission denied
+ git alias-yes
yes
+ git alias-no
fatal: cannot exec 'git-no': Permission denied

-Peff