From cfd92a5868828e57c94753d930be65e36df3fd59 Mon Sep 17 00:00:00 2001
From: Robert Bragg <robert@sixbynine.org>
Date: Wed, 19 Nov 2014 22:01:51 +0000
Subject: [PATCH] glx: Allow passing a Window to GLXGetDrawableAttributes

This updates __glXGetDrawable so that it does not require a context
pointer to be able to create a __GLXdrawable when a vanilla Window XID
is used as a GLXDrawable.

Removing this restriction means that DoGetDrawableAttributes can also
use this helper function allowing clients to pass Window XIDs as
GLXDrawables to glXQueryDrawable().

https://bugs.freedesktop.org/show_bug.cgi?id=54080
https://forums.oculus.com/viewtopic.php?f=20&t=16201
https://forums.oculus.com/viewtopic.php?f=34&t=16664

Signed-off-by: Robert Bragg <robert@sixbynine.org>
---
 glx/glxcmds.c | 40 +++++++++++++++++++++++-----------------
 1 file changed, 23 insertions(+), 17 deletions(-)

diff --git a/glx/glxcmds.c b/glx/glxcmds.c
index d11c667..115f9d5 100644
--- a/glx/glxcmds.c
+++ b/glx/glxcmds.c
@@ -470,6 +470,9 @@ __glXGetDrawable(__GLXcontext * glxc, GLXDrawable drawId, ClientPtr client,
 {
     DrawablePtr pDraw;
     __GLXdrawable *pGlxDraw;
+    __GLXscreen *pGlxScreen;
+    __GLXconfig *config;
+    XID vid;
     int rc;
 
     if (validGlxDrawable(client, drawId, GLX_DRAWABLE_ANY,
@@ -483,13 +486,6 @@ __glXGetDrawable(__GLXcontext * glxc, GLXDrawable drawId, ClientPtr client,
         return pGlxDraw;
     }
 
-    /* No active context and an unknown drawable, bail. */
-    if (glxc == NULL) {
-        client->errorValue = drawId;
-        *error = BadMatch;
-        return NULL;
-    }
-
     /* The drawId wasn't a GLX drawable.  Make sure it's a window and
      * create a GLXWindow for it.  Check that the drawable screen
      * matches the context screen and that the context fbconfig is
@@ -502,19 +498,30 @@ __glXGetDrawable(__GLXcontext * glxc, GLXDrawable drawId, ClientPtr client,
         return NULL;
     }
 
-    if (pDraw->pScreen != glxc->pGlxScreen->pScreen) {
+    pGlxScreen = glxGetScreen(pDraw->pScreen);
+    if (!pGlxScreen) {
         client->errorValue = pDraw->pScreen->myNum;
         *error = BadMatch;
         return NULL;
     }
 
-    if (!validGlxFBConfigForWindow(client, glxc->config, pDraw, error))
+    vid = wVisual((WindowPtr) pDraw);
+    if (!validGlxVisual(client, pGlxScreen, vid, &config, error)) {
+        client->errorValue = vid;
+        *error = BadMatch;
+        return NULL;
+    }
+
+    if (glxc != NULL && config != glxc->config) {
+        client->errorValue = drawId;
+        *error = BadMatch;
         return NULL;
+    }
 
-    pGlxDraw = glxc->pGlxScreen->createDrawable(client, glxc->pGlxScreen,
-                                                pDraw, drawId,
-                                                GLX_DRAWABLE_WINDOW,
-                                                drawId, glxc->config);
+    pGlxDraw = pGlxScreen->createDrawable(client, pGlxScreen,
+                                          pDraw, drawId,
+                                          GLX_DRAWABLE_WINDOW,
+                                          drawId, config);
     if (!pGlxDraw) {
 	*error = BadAlloc;
 	return NULL;
@@ -1907,12 +1914,11 @@ DoGetDrawableAttributes(__GLXclientState * cl, XID drawId)
 {
     ClientPtr client = cl->client;
     xGLXGetDrawableAttributesReply reply;
-    __GLXdrawable *pGlxDraw;
-    CARD32 attributes[14];
     int numAttribs = 0, error;
+    __GLXdrawable *pGlxDraw = __glXGetDrawable(NULL, drawId, client, &error);
+    CARD32 attributes[14];
 
-    if (!validGlxDrawable(client, drawId, GLX_DRAWABLE_ANY,
-                          DixGetAttrAccess, &pGlxDraw, &error))
+    if (pGlxDraw == NULL)
         return error;
 
     attributes[0] = GLX_TEXTURE_TARGET_EXT;
-- 
2.1.3