Index: cairo-1.17.6/src/cairo-xlib-render-compositor.c
===================================================================
--- cairo-1.17.6.orig/src/cairo-xlib-render-compositor.c
+++ cairo-1.17.6/src/cairo-xlib-render-compositor.c
@@ -1325,10 +1325,10 @@ _cairo_xlib_surface_add_glyph (cairo_xli
 	    }
 	    n = new;
 	    d = (uint32_t *) data;
-	    do {
+	    while (c--) {
 		*n++ = bswap_32 (*d);
 		d++;
-	    } while (--c);
+	    }
 	    data = (uint8_t *) new;
 	}
 	break;