bug#16711: 24.3.50; Error: pre-redisplay-function

[Stefan Monnier <monnier@iro.umontreal.ca>]

> I've been bitten by this intermitently for the last few weeks; it
> appears to be happening more often now.
> Observed initially in W3 when rendering heavy-weight web pages; it also
> shows up in eww.
> You get a variable depth exeeds max eval depth error repeatedly --

Hmm.. can you come up with a recipe to reproduce it?

> turning on debug doesn't yield any additional info.

Indeed, pre-redisplay-function is run at a time where we can't
conveniently redisplay, I think, so we can't drop into the debugger.

> The fix appears to be to set pre-redisplay-function to nil

That's obviously just a workaround.

> --- looking at the code, I've not figured out what that variable does

The variable doesn't do anything, it's just a hook.
Its default value is used to implement the highlighting of the active region.


        Stefan