Re: maintaining etags

[Eli Zaretskii <eliz@gnu.org>]

> Date: Mon, 11 May 2015 17:37:22 +0200
> From: Francesco Potortì <pot@gnu.org>
> Cc: emacs-devel@gnu.org, eller.helmut@gmail.com,
>  Dmitry Gutov <dgutov@yandex.ru>, Stefan Monnier <monnier@IRO.UMontreal.CA>
> 
> Eli, I see that you move around Etags's state machinery without problems.

I wouldn't say "without problems", it took me a while staring at the
state machines to pick up enough to be able to think of a solution.
That part of etags is not easily penetrated (the parts that deal with
other languages are easier). 

> Anyway, when I used to patch Etags, I always run a regression test,
> then updated the regression test with the case the patch was meant to
> address.  The tests that I used can be found in the tree at
> <http://fly.isti.cnr.it/pub/software/unix/etags-regression-test.tar>,
> together with some garbage.  The tests are invoked from the Makefile as
> the default target.  If, as I hope, someone will care to install the
> regression tests in the Emacs tree I can assist with answers to
> questions. 

Thanks, I will definitely run the test suite, I didn't know about it.
I will also look intyo adding it to the Emacs regression suite.

> The patch you propose is the sort of patch that should be run against a
> regression test, as it is not always obvious what will happen in the
> general case.

Agreed.  (I did run it on the entire Emacs tree and examined the
differences one by one against the previous version, but the more the
better, of course.)