On Thu 19 Jan 2023 at 19:09:19 -0600, Matthew D. Fuller wrote:
> On Sun, Jan 15, 2023 at 07:14:24PM +0100 I heard the voice of
> Rhialto, and lo! it spake thus:
> >
> > Unfortunately I got a core dump from cwtm (compiled Dec 17).
> [...]
> 
> > (gdb) print cmap
> > $1 = (TwmColormap *) 0x101000100000001
> >
> > (gdb) print *cwin
> > $2 = {w = 79691778, colormap = 0x101000100000001, visibility = 2047083, 
> >   refcnt = 1}
> 
> That's a new one on me.  Every time I see colormaps I cry a little
> inside, but I haven't seen them crash anything ever and I dunno what
> could be causing that...

Somehow it feels like something is overwriting the contents of the *cwin
struct; the values look too wrong to be able to be derived from a proper
assignment. In particular the 0x101000100000001 feels like a bitmask...
And such things might not even be caught by valgrind or an address
sanitizer, if the overlows are limited and only write into allocated
memory... although I didn't try it yet.

> Hey, we can just assume everybody's running 24bpp by now, and
> eliminate separate per-window colormaps entirely, right?  That's
> definitely a small simple change that won't break anything...

Some time ago I wanted to try that authentic feeling of 1 bit per pixel,
but this X server doesn't even support that any more... 

-Olaf.
-- 
___ "Buying carbon credits is a bit like a serial killer paying someone else to
\X/  have kids to make his activity cost neutral." -The BOFH    falu.nl@rhialto

Attachment: signature.asc
Description: PGP signature

Reply via email to