Fixes to git commands hardening.

[layus]

I tested the current release, and it breaks at update time and for changelog generation.

The issue is that you need to be in the git_dir for git to work correctly for submodules, but that you cannot move to the worktree when cloning (because it does not exist yet).

The changelog was broken because make_git_command was not available in that script.
I moved one function around and exported it.

I have now tested my changes within and outside vcsh (GIT_DIR set) for the following operations:

• init (clone)
• update
• plugin removal
• changelog
• log (error reporting)

My apologizes for not having properly tested my previous patches.

[ryanoasis]

Thanks, I just haven't gotten around to it yet. Apologies.

[layus]

No problem :-)