bug#43702: Emacs master: Incorrect highlighting in regexp isearch.

[Eli Zaretskii]

> From: Juri Linkov <juri@linkov.net>
> Cc: drew.adams@oracle.com,  acm@muc.de,  larsi@gnus.org,  
> 43702@debbugs.gnu.org
> Date: Wed, 07 Oct 2020 11:09:09 +0300
> 
> > I don't think I understand the change, and the documentation doesn't
> > seem to help.  It seems like now there are just two faces that are
> > used alternately, i.e. one face for odd-numbered groups, the other for
> > even-numbered groups?  If this is the case, why doesn't the
> > documentation say so explicitly?  And if this is not the case, what
> > did I miss?
> 
> Yes, by default isearch-group-1 is used for odd-numbered groups,
> and isearch-group-2 for even-numbered groups.
> 
> But when a user or a theme author will define a new face
> isearch-group-3, then isearch-group-3 will be used to highlight
> groups 3, 6, 9, 12, ..., the isearch-group-2 face to highlight
> groups 2, 5, 8, 11, ..., the isearch-group-1 face to highlight
> groups 1, 4, 7, 10, ...

OK, I clarified this in the docs.

> >> I suppose you agree that the previous color palette in isearch
> >> with a color gradient is not suitable for highlighting of group matches
> >> because while looking at highlighted matches it's quite impossible to
> >> say which color corresponds to which group number.
> >
> > And with the current implementation on master it is possible?  If so,
> > how?
> 
> With only 2 default group faces it's possible to see that one of them
> isearch-group-1 is brighter than the default isearch face, and another
> isearch-group-2 is darker than the default isearch face.

No, I meant to ask if it's possible to say which color corresponds to
which group number.