egl/x11/sw: fix partial image uploads

* swrast allocates images aligned to 64x64 tiles, which results in images
  that are larger than the window. PutImage requests must be clamped on
  the y-axis to avoid uploading/damaging out-of-bounds regions
* winsys coords are y-inverted

cc: mesa-stable

Reviewed-by: Adam Jackson <ajax@redhat.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/29910>

src/egl/drivers/dri2/platform_x11.c

@@ -174,6 +174,11 @@ swrastPutImage(__DRIdrawable *draw, int op, int x, int y, int w, int h,
       return;
    }
 
+   /* clamp to drawable size */
+   if (y + h > dri2_surf->base.Height)
+      h = dri2_surf->base.Height - y;
+   /* y-invert */
+   y = dri2_surf->base.Height - y - h;
    if (size < max_req_len) {
       cookie = xcb_put_image(
          dri2_dpy->conn, XCB_IMAGE_FORMAT_Z_PIXMAP, dri2_surf->drawable, gc, w,