Re: perl mode color highlighting working badly

[martin rudalics]

I see three potential problems with your approach:

As far as I understand `font-lock-syntactically-fontified' is not reset
after a buffer change.  Hence `font-lock-fontify-syntactically-region'
and `font-lock-fontify-syntactic-keywords-region' might fail both after
a buffer has been modified.  I believe that `jit-lock-after-change'
should contain something like

       (setq font-lock-syntactically-fontified
             (min font-lock-syntactically-fontified start))


Moreover I don't know what `font-lock-syntax-props-depend-on-themselves'
is needed for.  `font-lock-fontify-syntactically-region' should work
correctly without it since it starts at `sbeg' anyway.  On the other
hand, scrolling upwards into unfontified text might become slower since
you alway reset `font-lock-syntactically-fontified' to END even if the
entire buffer is already syntactically fontified.

Finally, doing `font-lock-fontify-syntactically-region' from `sbeg'
without doing a `font-lock-fontify-keywords-region' from `sbeg' too
seems problematic.  But I'll have to study this more thoroughly yet.
Hence don't take my remarks too seriously.