XRenderFindVisualFormat() is at several places used in xcompmgr.c, without ever checking for the return value. When running FlightGear (http://www.flightgear.org/), which is an (optionally) SDL using OpenGL application, XRenderFindVisualFormat() returns 0. This is *unchecked* handed over to XRenderCreatePicture() (lines 662, 792, 829, and 1726), which dereferences the null pointer. 0 is a valid return value of XRenderFindVisualFormat().
I've seen more of those in uncover from xapps, this crashes uncover if composite was disabled on the server
The crashes happened on Linux 2.6.7 with nVidia driver v6111 and both Xorg and xcompmgr from CVS/HEAD as of yesterday (2004/10/4). FlightGear doesn't run in "fullscreen" mode, but with a geometry that equals screen size and with window decoration. Bugs #1215 ("Fullscreen games cause xcompmgr to segfault.") and #1363 ("Fullscreen OpenGL apps crash server") could refer to the same xcompmgr bug.
Both the related (possibly duplicate) bugs are closed. Closing this one as well. Please reopen if it remains an issue.
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