Emacs freezes and takes 100% CPU

Emacs freezes and takes 100% CPU

[Markus Gritsch]

Hi,

I think I have found a serious bug.  The minimum .emacs file to 
reproduce the bug looks like:

--- 8< ---

(setq-default truncate-lines t)
(custom-set-variables
   '(hscroll-margin 20)
   '(hscroll-step 1)
)

--- 8< ---

Setting all three variables is necessary.  After starting Emacs, I
change the horizontal width of the Emacs frame to something quite
narrow, and then I try to move the cursor in the first line to the right
-> Emacs freezes.

I am using the prebuilt CVS Emacs for Windows from 
http://www.crasseux.com/emacs/.  Can someone on another platform please 
try to reproduce the bug, to see if it is specific to the Win32 version 
or a general problem?

Thanks in advance,
Markus

Re: Emacs freezes and takes 100% CPU

[David Hunter]

Markus Gritsch wrote:
> I am using the prebuilt CVS Emacs for Windows from 
> http://www.crasseux.com/emacs/.  Can someone on another platform please 
> try to reproduce the bug, to see if it is specific to the Win32 version 
> or a general problem?

I have reproduced it on today's CVS, my mingw build, Windows XP SP2.

Steps to reproduce:

- Set your .emacs file to the minimum reported by Markus
- Dismiss welcome screen and reach *scratch*
- Move point to first line (;; This buffer..)
- Resize window width to less than 21: arrows will appear in the left fringe
- Resize window width to exactly 21, so left fringe arrows disappear
- Move point right twice

What's interesting is, as the window width goes below 21, the buffer starts to scroll itself horizontally, such that arrows appear in the left fringe.  But when you click on the left fringe, the buffer scrolls in the opposite direction expected.  You also can't move point to column 0 anymore.

-Dave