+ /* Clip the read region against the src buffer bounds.
+ * We'll still allocate a temporary buffer/texture for the original
+ * src region size but we'll only read the region which is on-screen.
+ * This may mean that we draw garbage pixels into the dest region, but
+ * that's expected.
+ */
+ readX = srcx;
+ readY = srcy;
+ readW = width;
+ readH = height;
+ _mesa_clip_readpixels(ctx, &readX, &readY, &readW, &readH, &unpack);
+ readW = MAX2(0, readW);
+ readH = MAX2(0, readH);
+