[PATCH 1 of 2] filemerge: add support for multiple merge tool versions (RFC)

[Matt Mackall]

On Tue, 2015-12-22 at 19:34 +0100, Mathias De Maré wrote:
> On Mon, Dec 21, 2015 at 2:29 PM, Yuya Nishihara <yuya at tcha.org> wrote:
> 
> > On Sun, 20 Dec 2015 08:48:49 +0100, Mathias De Maré wrote:
> > > On Fri, Dec 18, 2015 at 8:28 PM, Matt Mackall <mpm at selenic.com> wrote:
> > > > On Wed, 2015-12-16 at 01:07 -0600, Mathias De Maré wrote:
> > > > > # HG changeset patch
> > > > > # User Mathias De Maré <mathias.demare at gmail.com>
> > > > > # Date 1450249051 -3600
> > > > > #      Wed Dec 16 07:57:31 2015 +0100
> > > > > # Node ID 958659a81ec2cea8037e4e8ba1bf9841c0272f88
> > > > > # Parent  7e8a883da1711008262150bb6f64131812de3e0b
> > > > > filemerge: add support for multiple merge tool versions (RFC)
> > > > 
> > > > ENODOCS. But from trying to parse the test, it seems a little complex.
> > > > It'd be much simpler to have something like:
> > > > 
> > > > mytoolwithauto = /usr/bin/mytool
> > > > mytoolwithauto.featurecheck = "--help", ".*--auto-merge.*"
> > > > 
> > > Hm, that does seem a lot less complex. I'll have a look if I can create
> > > something like this (and document it). Thanks!
> > 
> > FWIW, it won't be useful on Windows because GUI applications can't access
> > to
> > stdout in general. For example, "kdiff3 --confighelp" opens GUI on Windows.
> > 
> 'meld --help' doesn't print anything and doesn't launch a GUI either.
> 
> Would it be acceptable to simply disable the feature check on Windows? That
> would mean the experience on Windows stays the same, but the experience on
> other OS'es improves.

I'd rather not. Similar issues probably exist for some Mac and Linux editors
because kids today don't do Unix good. And it forecloses feature detection with
more sensible tools. 

Another strategy would be to try running with the option and looking at
output/exit codes.

-- 
Mathematics is the supreme nostalgia of our time.