Coverity report #750:

Event var_compare_op: Added "xr" due to comparison "xr != 0"
Also see events: [var_deref_model]
At conditional (1): "xr != 0" taking false path
At conditional (2): "(r)->numRects == 0" taking true path

189  	    if (xr || !r->numRects)

Event var_deref_model: Variable "xr" tracked as NULL was passed to a function
that dereferences it. [model]
Also see events: [var_compare_op]

190  		_XRenderSetPictureClipRectangles (dpy, info, picture, 0, 0, 
191  						  xr, r->numRects);
192  	    if (xr)
193  		_XFreeTemp(dpy, (char *)xr, total);
194  	    UnlockDisplay(dpy);
195  	    SyncHandle();
196  	}

Attaching a proposed change.