QPainter::drawPixmap crash on QGLPixelBuffer

Here is a backtrace of the crash:

QX11Info::screen (this=0x0) at kernel/qx11info_x11.cpp:476
476

{ return x11data ? x11data->screen : QX11Info::appScreen(); }

#0 QX11Info::screen (this=0x0) at kernel/qx11info_x11.cpp:476
#1 0x00007fea6905a4fe in qt_resolveTextureFromPixmap (paintDevice=0x21fef30) at qgl_x11.cpp:1612
#2 0x00007fea6905a62d in QGLContextPrivate::bindTextureFromNativePixmap (this=<value optimized out>, pmd=0x3263ed0,
key=72057714297012224, options=

{i = 1964533744}

) at qgl_x11.cpp:1634
#3 0x00007fea69006e48 in QGLContextPrivate::bindTexture (this=0x21f8660, pixmap=@0x3281420, target=3553, format=6408,
options=

{i = 1964533904}

) at qgl.cpp:2326
#4 0x00007fea69050820 in QGL2PaintEngineEx::drawPixmap (this=0x7fea44db0c60, dest=@0x7fff75186910, pixmap=@0x3281420,
src=@0x7fff751868f0) at gl2paintengineex/qpaintengineex_opengl2.cpp:1433
#5 0x00007fea6866812c in QPaintEngineEx::drawPixmap (this=0x7fea44db0c60, pos=@0x7fff75186ad0, pm=@0x3281420)
at painting/qpaintengineex.cpp:948
#6 0x00007fea6867aa3d in QPainter::drawPixmap (this=0x7fff75188430, p=@0x7fff75186ad0, pm=@0x3281420)
at painting/qpainter.cpp:5238

It looks like the issue is in qt_resolveTextureFromPixmap in opengl/qgl_x11.cpp. The return value from qt_x11Info() is 0 but it is never checked:

const QX11Info *xinfo = qt_x11Info(paintDevice);
QGLExtensionMatcher extensions(glXQueryExtensionsString(xinfo->display(), xinfo->screen()));

This has changed from 4.6.0 where QGLExtentionMatcher (and thus QX11Info) is not used.

I assume qt_x11Info returns 0 because QPaintDevice::devType() isn't QInternal::Widget or QInternal::Pixmap. The devType() for the current painter is 6:

(gdb) up
#1 0x00007fea6905a4fe in qt_resolveTextureFromPixmap (paintDevice=0x21fef30) at qgl_x11.cpp:1612
1612 QGLExtensionMatcher extensions(glXQueryExtensionsString(xinfo->display(), xinfo->screen()));
(gdb) print paintDevice
$1 = (class QPaintDevice *) 0x21fef30
(gdb) print paintDevice->devType()
$2 = 6