Re: why does occur depropertize matching lines?

[Juri Linkov <juri@jurta.org>]

"Drew Adams" <drew.adams@oracle.com> writes:
> I think this is a considerable setback wrt usability: it represents an
> information loss for users. I don't know how much of the pb was program
> "trouble" and how much was user "confusion", but I'm one user who would be
> willing to trade, say, the confusion of some extra, ineffective mouse-face
> highlighting for the benefit of informative syntactic highlighting. Such
> highlighting is all the more helpful when lines have been taken out of
> context (as in occur).

Even now occur partly preserves highlighting for some lines: when
called with a numeric prefix argument occur displays context lines
highlighted with their original faces whereas highlighting from matching
lines is removed.  This is too weird.  I can't find a reason for that.

I think occur should preserve highlighting of matching lines as well
(or at least preserve face properties if other properties are too confusing).

However, I see another problem: matches are not highlighted anymore
with `list-matching-lines-face' because when a character has two properties

  font-lock-face [bold]                   ;; from `list-matching-lines-face'
  face           [font-lock-keyword-face] ;; from source buffer

`face' property takes precedence over `font-lock-face'.

If it would be possible to merge these two properties somehow...

-- 
Juri Linkov
http://www.jurta.org/emacs/