glx: Prepare driFetchDrawable for no-config contexts

When we look up the DRI drawable state we need to associate an fbconfig
with the drawable. With GLX_EXT_no_config_context we can no longer infer
that from the context and must instead query the server.

Signed-off-by: Adam Jackson <ajax@redhat.com>
Reviewed-by: Ian Romanick <ian.d.romanick@intel.com>

src/glx/dri_common.c

@@ -396,12 +396,25 @@ driDestroyConfigs(const __DRIconfig **configs)
    free(configs);
 }
 
+static struct glx_config *
+driInferDrawableConfig(struct glx_screen *psc, GLXDrawable draw)
+{
+   unsigned int fbconfig = 0;
+
+   if (__glXGetDrawableAttribute(psc->dpy, draw, GLX_FBCONFIG_ID, &fbconfig)) {
+      return glx_config_find_fbconfig(psc->configs, fbconfig);
+   }
+
+   return NULL;
+}
+
 _X_HIDDEN __GLXDRIdrawable *
 driFetchDrawable(struct glx_context *gc, GLXDrawable glxDrawable)
 {
    struct glx_display *const priv = __glXInitialize(gc->psc->dpy);
    __GLXDRIdrawable *pdraw;
    struct glx_screen *psc;
+   struct glx_config *config = gc->config;
 
    if (priv == NULL)
       return NULL;
@@ -418,8 +431,13 @@ driFetchDrawable(struct glx_context *gc, GLXDrawable glxDrawable)
       return pdraw;
    }
 
-   pdraw = psc->driScreen->createDrawable(psc, glxDrawable,
-                                          glxDrawable, gc->config);
+   if (config == NULL)
+      config = driInferDrawableConfig(gc->psc, glxDrawable);
+   if (config == NULL)
+      return NULL;
+
+   pdraw = psc->driScreen->createDrawable(psc, glxDrawable, glxDrawable,
+                                          config);
 
    if (pdraw == NULL) {
       ErrorMessageF("failed to create drawable\n");

src/glx/glx_pbuffer.c

@@ -272,9 +272,9 @@ DestroyDRIDrawable(Display *dpy, GLXDrawable drawable, int destroy_xdrawable)
  * 10.  Given that, this routine should try to use an array on the stack to
  * capture the reply rather than always calling Xmalloc.
  */
-static int
-GetDrawableAttribute(Display * dpy, GLXDrawable drawable,
-                     int attribute, unsigned int *value)
+int
+__glXGetDrawableAttribute(Display * dpy, GLXDrawable drawable,
+                          int attribute, unsigned int *value)
 {
    struct glx_display *priv;
    xGLXGetDrawableAttributesReply reply;
@@ -825,7 +825,7 @@ glXQueryDrawable(Display * dpy, GLXDrawable drawable,
       }
    }
 #else
-   GetDrawableAttribute(dpy, drawable, attribute, value);
+   __glXGetDrawableAttribute(dpy, drawable, attribute, value);
 #endif
 }
 
@@ -838,7 +838,7 @@ _GLX_PUBLIC int
 glXQueryGLXPbufferSGIX(Display * dpy, GLXPbufferSGIX drawable,
                        int attribute, unsigned int *value)
 {
-   return GetDrawableAttribute(dpy, drawable, attribute, value);
+   return __glXGetDrawableAttribute(dpy, drawable, attribute, value);
 }
 #endif
 
@@ -909,7 +909,7 @@ glXGetSelectedEvent(Display * dpy, GLXDrawable drawable, unsigned long *mask)
     * we could just type-cast the pointer, but why?
     */
 
-   GetDrawableAttribute(dpy, drawable, GLX_EVENT_MASK_SGIX, &value);
+   __glXGetDrawableAttribute(dpy, drawable, GLX_EVENT_MASK_SGIX, &value);
    *mask = value;
 #endif
 }

src/glx/glxclient.h

@@ -841,6 +841,10 @@ indirect_create_context_attribs(struct glx_screen *base,
                                 const uint32_t *attribs,
                                 unsigned *error);
 
+
+extern int __glXGetDrawableAttribute(Display * dpy, GLXDrawable drawable,
+                                     int attribute, unsigned int *value);
+
 #ifdef __cplusplus
 }
 #endif