Subject: Re: bug#35202: 27.0.50; Info-quoted false positives and false negatives

From: Mauro Aranda <[email-masked]>
Date: Tue, 9 Apr 2019 14:40:48 -0300

> Thanks, but I'm worried how we will be able to make sure this change
> doesn't break display in some other places.  Would it make sense to
> search all our Info files for the new regexp, and examine the display
> of all the places that match?  Or did you already do that?
> .

Hello Eli.

I must admit, I didn't check thoroughly, so I can't be sure it doesn't
break the font-locking of quotes in other places.

I have come up with the following way of testing a new regexp:
Step 1: In Info files that come with Emacs, search the original
regexp and the new regexp for all the matches.  Compare both results,
discarding the insersecting values (IOW, discard the matches for which a
new regexp wouldn't introduce new behavior).

Step 2: Based on the previous, analyze each new behavior, to see if a
new regexp does the right thing, or not.

Step 3: Accept, adjust or discard the regexp, accordingly.  If not
accepted, go back to Step 1 for a new iteration.

Provided the final regexp doesn't break display in other places (and
of course, improves the current behavior), would the procedure
I've just described be enough to trust a change?