bug#41441: 26.3; mhtml misbehaving font-lock extend region can cause Emacs to hang

[Dmitry Gutov]

On 28.05.2020 22:31, Anders Lindgren wrote:
> When having conflicting functions, the result is somewhat arbitrary. 
> Effectively, functions later i the list take precedence over earlier, 
> but picking one result is better than a hanging Emacs.

I wouldn't say a non-deterministic result is much better than hanging.

We should just disallow this kind of behavior in these functions. Unless 
there is some very convincing evidence of its necessity.