Re: [PATCH v3 1/2] difftool: add a skeleton for the upcoming builtin

[Johannes Schindelin <Johannes.Schindelin@gmx.de>]

Hi Junio,

On Tue, 29 Nov 2016, Junio C Hamano wrote:

> Johannes Schindelin <Johannes.Schindelin@gmx.de> writes:
> 
> > So the suggestion by both you and Peff, to use an environment variable,
> > which is either global, or requires the user to set it manually per
> > session, is simply not a good idea at all.
> 
> As I already said, I do not have a strong preference between config
> and env.  I raised the env as a possible alternative that you can
> think about its pros and cons, and as I already said, if you thought
> and your concluded that config would work better for your needs,
> that is fine by me.

The env flat out fails, on the grounds of not integrating nicely into a
Git for Windows installer.

The config kinda works now. But for what price. It stole 4 hours I did not
have. When the libexec/git-core/use-builtin-difftool solution took me a
grand total of half an hour to devise, implement and test.

And you know what? I still do not really see what is so bad about it.

And I still see what is bad about the config "solution": it *creates* a
chicken-and-egg problem with the order of config reading vs running
scripts. It *creates* problems for requiring to spawn a `git config` call
because reading the config in-process would mess up the global variables
and environment *beyond repair*, making it *impossible* to even spawn the
git-legacy-difftool Perl script.

In short: the config setting now works. But it is ugly as hell. I wish I
never had listened to you.

Ciao,
Dscho