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

[Jeff King <peff@peff.net>]

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

> +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