SunView 4.0.3 pr_load() fails occasionally

[Alan Sparks]

I'm having a problem for which I cannot find a cause or cure.  Maybe
someone out there has a clue...

I wrote an image display program for SunView some time ago.  It is capable
(using other PD software as filters) of displaying GIF-format images.

The basic algorithm is, after ascertaining that a file is a GIF file, the
program popens() a process running gif2ras (author Patrick Naughton) for
reading, and does a pr_load on that file pointer.  The returned pixrect is
then copied, after centering, to the canvas pixrect.

Funny thing is, 95% of the files load OK, but some come up all black, some
in the background color, and several come up with "strange" colors.
Funnier thing is, if I pipe the output of gif2ras into screenload, the
image is displayed correctly.

As I have RTFM'ed, does anyone know if SunOS 4.0.3 pr_load() has any known
bugs?  Does anyone have a suggestion on how to debug such a problem?  Can
anyone tell me how screenload works, so I can figure out what I'm doing
differently?  And, (whew!) does 4.1 contain a patch?

Thanks in advance.  Please email me at the above address; I'll post a
synopsis of the responses.

-Alan