Subject: Re: bug#29159: 27.0.50; Hang in HTML/CSS code

From: Simen Heggestøyl <[email-masked]>
Date: Sun, 26 Nov 2017 15:52:38 +0100

Stefan Monnier <[email-masked]> writes:
> Could you give some details?
> Functions on font-lock-extend-region-functions should *never* shrink
> a region (since that risks inf-looping, obviously).  After all, it's
> called "...-extend-...", right?
>
> So if font-lock-extend-region-multiline puts beg at 39, it's incorrect
> for mhtml--extend-font-lock-region to move it back to 40.

`font-lock-beg' got set back to 40 from 39 at line 184 from the call to
`previous-single-property-change'.

-- Simen