+ XMesaFreePixmap(b->xm_visual->display, b->backxrb->pixmap);
+ b->backxrb->pixmap = 0;
+ }
+
+ if (width > 0 && height > 0) {
+ /* Allocate new back pixmap */
+ b->backxrb->pixmap = XMesaCreatePixmap(b->xm_visual->display,
+ b->frontxrb->drawable,
+ width, height,
+ GET_VISUAL_DEPTH(b->xm_visual));