[BUG] Directory probing for aliases

[Vasiliy Yeremeyev <vayerx@gmail.com>]

Hi,
Git aliases stop working when user doesn't have permissions to any
directory within $PATH list:

% git config alias.br branch
% git br
fatal: cannot exec 'git-br': Permission denied

Problem seems to be in directories probing:

execve("/usr/libexec/git-core/git-br", ["git-br"], [/* 76 vars */]) =
-1 ENOENT (No such file or directory)
execve("/home/vayerx/bin/git-br", ["git-br"], [/* 76 vars */]) = -1
ENOENT (No such file or directory)
execve("/usr/local/bin/git-br", ["git-br"], [/* 76 vars */]) = -1
ENOENT (No such file or directory)
execve("/usr/bin/git-br", ["git-br"], [/* 76 vars */]) = -1 ENOENT (No
such file or directory)
execve("/bin/git-br", ["git-br"], [/* 76 vars */]) = -1 ENOENT (No
such file or directory)
execve("/opt/bin/git-br", ["git-br"], [/* 76 vars */]) = -1 ENOENT (No
such file or directory)
execve("/usr/x86_64-pc-linux-gnu/gcc-bin/4.6.3/git-br", ["git-br"],
[/* 76 vars */]) = -1 ENOENT (No such file or directory)
execve("/usr/games/bin/git-br", ["git-br"], [/* 76 vars */]) = -1
EACCES (Permission denied)
write(2, "fatal: ", 7fatal: )      = 7
write(2, "cannot exec 'git-br': Permission"..., 39cannot exec
'git-br': Permission denied) = 39

(user doesn't have access to '/usr/games/bin' directory)
Everything works fine if '/usr/games/bin' is not listed in $PATH variable.
Standard/built-in git commands work fine regardless of  $PATH variable.

-- 
With Best Regards,
Vasiliy Yeremeyev