#1111: if we cannot create a gl context, detect it sooner, log the er…

…ror and skip trying to paint

git-svn-id: https://xpra.org/svn/Xpra/trunk@13292 3bb7dfac-3a0b-4e04-842a-767bc560f471

src/xpra/client/gl/gl_window_backing_base.py

@@ -370,17 +370,22 @@ def gl_init_shaders(self):
                 log("%s shader initialized", name)
 
     def gl_context(self):
-        if not self._backing:
+        b = self._backing
+        if not b:
             log("Error: no OpenGL backing")
             return None
-        if not is_realized(self._backing):
+        if not is_realized(b):
             log.error("Error: OpenGL backing is not realized")
             return None
         w, h = self.size
         if w<=0 or h<=0:
             log.error("Error: invalid OpenGL backing size: %ix%i", w, h)
             return None
-        context = GLContextManager(self._backing)
+        try:
+            context = GLContextManager(b)
+        except Exception as e:
+            log.error("Error: %s", e)
+            return None
         log("%s.gl_context() GL Pixmap backing size: %d x %d, context=%s", self, w, h, context)
         return context
 

src/xpra/client/gl/gtk_compat.py

@@ -87,13 +87,17 @@ class GLContextManager(object):
 
         def __init__(self, widget):
             self.widget = widget
+            self.gldrawable = gtkgl.widget_get_gl_drawable(widget)
+            assert self.gldrawable, "failed to get the GL drawable for %s" % widget
+            self.glcontext = gtkgl.widget_get_gl_context(widget)
+            assert self.glcontext, "failed to get a GL context from %s" % widget
+
         def __enter__(self):
-            gldrawable = gtkgl.widget_get_gl_drawable(self.widget)
-            glcontext = gtkgl.widget_get_gl_context(self.widget)
-            assert gldrawable.gl_begin(glcontext)
+            assert self.gldrawable.gl_begin(self.glcontext)
+
         def __exit__(self, exc_type, exc_val, exc_tb):
-            gldrawable = gtkgl.widget_get_gl_drawable(self.widget)
-            gldrawable.gl_end()
+            self.gldrawable.gl_end()
+
         def __repr__(self):
             return "gtk2.GLContextManager(%s)" % self.widget