Re: bug-reference-prog-mode slows down CC Mode's scrolling by ~7%

[Eli Zaretskii]

> Date: Wed, 1 Sep 2021 17:33:06 +0000
> From: Alan Mackenzie <acm@muc.de>
> 
> When applied to C Mode, bug-reference-prog-mode slows down a scroll from
> point-min to point-max by around 7%.
> 
> Just how useful is bug-reference-prog-mode?  Is it really worth this 7%
> slowdown?

It is marginally useful, but 7% slowdown is too heavy a price, IMO.
This should be fixed.

(I thought that the code in jit-lock.el already handled this case by
computing a kind-of "maximum" out of all the return values of
jit-lock-functions, and treating a nil return value as expected, but
maybe my reading of the code was incorrect?)