XQuartz: xpr: The dri.c code for pixmaps was wrong in several ways. They weren't

being exported correctly by Xplugin.

This should fix a bug with the surface for a window, when an export fails.
Before the export could fail and leave behind an invalid (freed) pointer in the dix privates.

I have an idea of how to fix the GLXPixmaps now without using CGLSetOffScreen.

This work is a step towards that.  The Xplugin will need a small patch to fix an
issue that this change brought forth.

1 files changed, 26 insertions, 17 deletions

diff --git a/hw/xquartz/xpr/dri.c b/hw/xquartz/xpr/dri.c
index 50b478b9c..bcd0c65bc 100644
--- a/hw/xquartz/xpr/dri.c
+++ b/hw/xquartz/xpr/dri.c
@@ -408,7 +408,7 @@ CreateSurfaceForWindow(ScreenPtr pScreen, WindowPtr pWin, xp_window_id *widPtr)
     return pDRIDrawablePriv;
 }
 
-/* Return FALSE if an error occurs. */
+/* Return NULL if an error occurs. */
 static DRIDrawablePrivPtr
 CreateSurfaceForPixmap(ScreenPtr pScreen, PixmapPtr pPix) {
     DRIDrawablePrivPtr pDRIDrawablePriv;
@@ -417,7 +417,6 @@ CreateSurfaceForPixmap(ScreenPtr pScreen, PixmapPtr pPix) {
 
     if (pDRIDrawablePriv == NULL) {
         xp_error err;
-        xp_window_changes wc;
 
         /* allocate a DRI Window Private record */
         if (!(pDRIDrawablePriv = xcalloc(1, sizeof(*pDRIDrawablePriv)))) {
@@ -439,18 +438,10 @@ CreateSurfaceForPixmap(ScreenPtr pScreen, PixmapPtr pPix) {
             return NULL;
         }
 
-        wc.x = 0;
-        wc.y = 0;
-        wc.width = pPix->drawable.width;
-        wc.height = pPix->drawable.height;
-
-        err = xp_configure_surface(pDRIDrawablePriv->sid, XP_BOUNDS, &wc);
-
-        if(err != Success) {
-            xp_destroy_surface(pDRIDrawablePriv->sid);
-            xfree(pDRIDrawablePriv);
-            return NULL;
-        }
+        /* 
+         * The DRIUpdateSurface will be called to resize the surface
+         * after this function, if the export is successful.
+         */
 
         /* save private off of preallocated index */
         dixSetPrivate(&pPix->devPrivates, DRIPixmapPrivKey,
@@ -491,21 +482,39 @@ DRICreateSurface(ScreenPtr pScreen, Drawable id,
         /* NOT_DONE */
         return FALSE;
     }
-
     
-
+    
     /* Finish initialization of new surfaces */
     if (pDRIDrawablePriv->refCount == 0) {
         unsigned int key[2] = {0};
         xp_error err;
 
         /* try to give the client access to the surface */
-        if (client_id != 0 && wid != 0) {
+        if (client_id != 0) {
+            /*
+             * Xplugin accepts a 0 wid if the surface id is offscreen, such 
+             * as for a pixmap.
+             */
             err = xp_export_surface(wid, pDRIDrawablePriv->sid,
                                     client_id, key);
             if (err != Success) {
                 xp_destroy_surface(pDRIDrawablePriv->sid);
                 xfree(pDRIDrawablePriv);
+                
+                /* 
+                 * Now set the dix privates to NULL that were previously set.
+                 * This prevents reusing an invalid pointer.
+                 */
+                if(pDrawable->type == DRAWABLE_WINDOW) {
+                    WindowPtr pWin = (WindowPtr)pDrawable;
+                    
+                    dixSetPrivate(&pWin->devPrivates, DRIWindowPrivKey, NULL);
+                } else if(pDrawable->type == DRAWABLE_PIXMAP) {
+                    PixmapPtr pPix = (PixmapPtr)pDrawable;
+                    
+                    dixSetPrivate(&pPix->devPrivates, DRIPixmapPrivKey, NULL);
+                }
+                
                 return FALSE;
             }
         }