gallium/xlib: fix glXQueryDrawable() bugs, see bug 24320

src/gallium/state_trackers/glx/xlib/glx_api.c

@@ -1992,32 +1992,42 @@ glXCreatePbuffer( Display *dpy, GLXFBConfig config,
             break;
          case GLX_PRESERVED_CONTENTS:
             attrib++;
-            preserveContents = *attrib; /* ignored */
+            preserveContents = *attrib;
             break;
          case GLX_LARGEST_PBUFFER:
             attrib++;
-            useLargest = *attrib; /* ignored */
+            useLargest = *attrib;
             break;
          default:
             return 0;
       }
    }
 
-   /* not used at this time */
-   (void) useLargest;
-   (void) preserveContents;
-
    if (width == 0 || height == 0)
       return 0;
 
+   if (width > MAX_WIDTH || height > MAX_HEIGHT) {
+      /* If allocation would have failed and GLX_LARGEST_PBUFFER is set,
+       * allocate the largest possible buffer.
+       */
+      if (useLargest) {
+         width = MAX_WIDTH;
+         height = MAX_HEIGHT;
+      }
+   }
+
    xmbuf = XMesaCreatePBuffer( xmvis, 0, width, height);
    /* A GLXPbuffer handle must be an X Drawable because that's what
     * glXMakeCurrent takes.
     */
-   if (xmbuf)
+   if (xmbuf) {
+      xmbuf->largestPbuffer = useLargest;
+      xmbuf->preservedContents = preserveContents;
       return (GLXPbuffer) xmbuf->drawable;
-   else
+   }
+   else {
       return 0;
+   }
 }
 
 
@@ -2035,22 +2045,26 @@ void
 glXQueryDrawable( Display *dpy, GLXDrawable draw, int attribute,
                        unsigned int *value )
 {
+   GLuint width, height;
    XMesaBuffer xmbuf = XMesaFindBuffer(dpy, draw);
    if (!xmbuf)
       return;
 
+   /* make sure buffer's dimensions are up to date */
+   xmesa_get_window_size(dpy, xmbuf, &width, &height);
+
    switch (attribute) {
       case GLX_WIDTH:
-         *value = xmesa_buffer_width(xmbuf);
+         *value = width;
          break;
       case GLX_HEIGHT:
-         *value = xmesa_buffer_width(xmbuf);
+         *value = height;
          break;
       case GLX_PRESERVED_CONTENTS:
-         *value = True;
+         *value = xmbuf->preservedContents;
          break;
       case GLX_LARGEST_PBUFFER:
-         *value = xmesa_buffer_width(xmbuf) * xmesa_buffer_height(xmbuf);
+         *value = xmbuf->largestPbuffer;
          break;
       case GLX_FBCONFIG_ID:
          *value = xmbuf->xm_visual->visinfo->visualid;

src/gallium/state_trackers/glx/xlib/xm_api.c

@@ -228,7 +228,7 @@ get_drawable_size( Display *dpy, Drawable d, uint *width, uint *height )
  * \param width  returns width in pixels
  * \param height  returns height in pixels
  */
-static void
+void
 xmesa_get_window_size(Display *dpy, XMesaBuffer b,
                       GLuint *width, GLuint *height)
 {

src/gallium/state_trackers/glx/xlib/xm_api.h

@@ -323,6 +323,9 @@ struct xmesa_buffer {
    Colormap cmap;		/* the X colormap */
    BufferType type;             /* window, pixmap, pbuffer or glxwindow */
 
+   GLboolean largestPbuffer;    /**< for pbuffers */
+   GLboolean preservedContents; /**< for pbuffers */
+
    XImage *tempImage;
    unsigned long selectedEvents;/* for pbuffers only */
 
@@ -369,6 +372,10 @@ xmesa_delete_framebuffer(struct gl_framebuffer *fb);
 extern XMesaBuffer
 xmesa_find_buffer(Display *dpy, Colormap cmap, XMesaBuffer notThis);
 
+extern void
+xmesa_get_window_size(Display *dpy, XMesaBuffer b,
+                      GLuint *width, GLuint *height);
+
 extern void
 xmesa_check_and_update_buffer_size(XMesaContext xmctx, XMesaBuffer drawBuffer);