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

From: Jonathan Nieder <jrnieder@gmail.com>
Date: Mar 28, 2012, 21:01 UTC
Message-ID: <20120328210145.GG8982@burratino>
In-Reply-To: <20120328205144.GA10174@sigill.intra.peff.net>

Jeff King wrote:

> That is the cost of using the mkpath convenience function (otherwise,
> the compiler will complain that ".*" expects an int). We can do it
> manually, but in practice, do you really expect your PATH environment
> variable to overflow an int?

I'd think a check like

	if (end - p > INT_MAX)
		die("holy cow your PATH is big");

would be good enough.  Or even

	assert(end - p <= INT_MAX);

if there is some environment limit I forgot about that makes that always true.

Show 13 quoted lines

>> 	/*
>> 	 * When a command can't be found because one of the directories
>> 	 * listed in $PATH is unsearchable, execvp reports EACCES, but
>> 	 * careful usability testing (read: analysis of occasional bug
>> 	 * reports) reveals that "No such file or directory" is more
>> 	 * intuitive.
>> 	 */
>> 	if (errno == EACCES && cannot_find_in_PATH(file))
>> 		errno = ENOENT;
>
> I think we can even simplify cannot_find to "!exists_in_PATH" to make
> it even simpler. If it exists and execvp did not execute it, then it
> must be non-executable (or there is a race condition :) ).

Yeah, sounds good.  With Junio's caveat, that makes:

	if (errno == EACCES && !strchr(file, '/'))
		errno = exists_in_PATH(file) ? EACCES : ENOENT;