bug#6739: 24.0.50; hang in *VC-log* -- redisplaying?

[Dan Nicolaescu <dann@gnu.org>]

rogers-emacs@rgrjr.dyndns.org writes:

>    In emacs built from git on 17-July (on openSUSE GNU/Linux 11.0), I am
> experiencing frequent hanging in *VC-log* buffers.  In a fresh *VC-log*
> buffer, as soon as I type "SPC RET", the cursor disappears and I get no
> response.  Typing C-g restores control, though sometimes I have to C-g
> twice or more.  It appears to be a display problem, as the display
> updates to reflect keystrokes typed before the C-g -- and sometimes the
> first C-g will update the display partway, and the next will update it
> more.
>
>    Burying or killing the *VC-log* buffer makes the problem go away.
> Same with deleting the initial SPC character, which appears to be
> necessary.

Can you please look in the *Messages* buffer when the problem happens,
see if there's anything strange there.

>
>    I have had no luck tracking this down any further.  Setting
> debug-on-quit not only does not enter the debugger, it sometimes seems
> to cause emacs to hang indefinitely.  I assume the next step would be to
> start emacs under gdb, but I am not familiar enough with redisplay (or
> gdb for that matter) to know what to look for.  Any help would be
> appreciated.
>
> 					-- Bob Rogers
> 					   http://www.rgrjr.com/