This broke when gdk_gl_texture_quad moved to shaders. We need a specialized shader for the rectangle case.
5f9e6ec GdkGL: Fix up GL_ARB_texture_rectangle support
gdk/gdkgl.c | 80 ++++++++++++++++++++++++++++++++++++++------
gdk/gdkglcontextprivate.h | 5 +++
gdk/gdkinternals.h | 1 +
gdk/x11/gdkglcontext-x11.c | 47 +++++++++++++++-----------
4 files changed, 103 insertions(+), 30 deletions(-)
Upstream: git.gnome.org