[comp.windows.x] Bug in DECStation 3100 X server

battle@alphard.cs.utk.edu (David Battle) (12/14/89)

There appears to be a bug in DEC's X server for the DECStation 3100.  Try
an XGetImage from a pixmap with the image's width and height equal to 33.

At least under some circumstances this can cause garbage to be *written* into
the *pixmap*.  Changing the GetImage size from 33 to 32 will "fix" the problem.

I don't know if this bug exists on other servers.  I haven't observed this
problem with windows, but that doesn't mean it doesn't exist there also.

					-David L. Battle
					battle@battle.esd.ornl.gov

joel@pandora.pa.dec.com (Joel McCormack) (12/16/89)

> There appears to be a bug in DEC's X server for the DECStation 3100.  Try
> an XGetImage from a pixmap with the image's width and height equal to 33.

> At least under some circumstances this can cause garbage to be *written* into
> the *pixmap*.  Changing the GetImage size from 33 to 32 will "fix" the
> problem.


There was one line of code in GetImage which read ``*psrc = *pdst''
rather than the other way 'round.  This is fixed in UWS 2.2.  This is
actually a pretty old bug; it may have been fixed in UWS 2.1, but I
don't remember.

- Joel McCormack (decwrl!joel, joel@decwrl.dec.com)