GNU bug report logs -
#44930
27.1; X protocol error: BadMatch (...) on protocol request 73
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Reported by: Francesco Potortì <pot <at> gnu.org>
Date: Sat, 28 Nov 2020 19:37:01 UTC
Severity: normal
Found in version 27.1
Done: Alan Third <alan <at> idiocy.org>
Bug is archived. No further changes may be made.
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Message #14 received at 44930 <at> debbugs.gnu.org (full text, mbox):
>> In this moment I have a *w3m* buffer on a live Emacs. If I switch to it
>> on a text frame, everything is well. If I switch to it on an X display,
>> the frame dies (but Emacs survives). The error is
>>
>> X protocol error: BadMatch (invalid parameter attributes) on protocol request 73
>>
>> until I don't kill the buffer, I can reproduce the error at will. I
>> have no idea how to debug it. If I am instructed, I can try until Emacs
>> is alive.
>
>etc/DEBUG has some instructions for debugging X protocol errors;
>search for "If you encounter X protocol errors".
Ok. I fear I will not be able to do that quickly.
>In addition to what that says, it would be beneficial to understand
>what kind of X request is "request 73".
According to http://www.rahul.net/kenton/xproto/xrequests.html 73 is the
X protocol GetImage call.
According to https://www.x.org/wiki/guide/concepts/#index2h3, this is seldom
used, for example for making screenshots or for redrawing. The second
usage could explain why it happens when I switch buffer and why the
debugger points to the internal C function redisplay_internal()
The XGetImage function is called twice from gtkutil.c and thrice from
image.c, so one of these is apparently failing.
According to
https://www.x.org/releases/X11R7.7/doc/xproto/x11protocol.html#requests:GetImage
the call may return a Match error when the pixmap or window to be
returned do not satisfy certain geometric criteria.
This is strange, because the error happens only when I switch to a
specific buffer, which makes me think that it depends on the buffer
contents. Is there a way to save the buffer contents including
attributes (fonts, overlays and other things that I do not know about)
to disk, so that I can easily recreate a buffer with the strange
property of causing this error?
This bug report was last modified 4 years and 220 days ago.
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