Re: [BUG] typo DWIMery with alias broken (cd to random dir)

On Tue, Jan 26, 2016 at 2:37 PM, Michael J Gruber
[off-list ref] wrote:

Hi there,

with current next (989ee58 plus local additions) it seems that typo
DWIMery with aliases is broken, see below.

It appears that the typo DWIMery is broken only when there is a unique
automatic DWIM substitution for a mistyped alias.

I haven't bisected yet, but I suspect this to be related to recent
changes regarding the environment in which commands/aliases are started
(though this happens without extra work trees), so I'm cc'ing an expert
in that area. Funny, though, that my user name shows up...

I think the reason is that git.c's handle_alias() (or something else)
calls restore_env() multiple times, and restore_env frees orig_cwd such
that subsequent restore_env(0) with external_alias=0 tries to cd to a
random location.

I have no idea whether orig_cwd=0 after freeing or something else would
be the proper fix.

I think the key is to reset saved_env_before_alias to zero in
restore_env(). With that flag remains set, the second save_env turns
no-op. orig_cwd should be reset too, but that's minor. It's working
for me. I'll send a patch later.
-- 
Duy