1 files changed, 18 insertions, 15 deletions

diff --git a/sys/dev/syscons/scmouse.c b/sys/dev/syscons/scmouse.c
index f96c157cb4b5..601e6ada5260 100644
--- a/sys/dev/syscons/scmouse.c
+++ b/sys/dev/syscons/scmouse.c
@@ -232,30 +232,33 @@ sc_draw_mouse_image(scr_stat *scp)
 void
 sc_remove_mouse_image(scr_stat *scp)
 {
-    int size;
-    int i;
+    int cols, i, rows;
 
     if (ISGRAPHSC(scp))
 	return;
 
     SC_VIDEO_LOCK(scp->sc);
-    (*scp->rndr->draw_mouse)(scp,
-			     (scp->mouse_oldpos%scp->xsize + scp->xoff)
-			         * scp->font_width,
-			     (scp->mouse_oldpos/scp->xsize + scp->yoff)
-				 * scp->font_size,
+    (*scp->rndr->draw_mouse)(scp, scp->mouse_oldxpos, scp->mouse_oldypos,
 			     FALSE);
-    size = scp->xsize*scp->ysize;
+    /*
+     * To simplify the renderer and ensure undrawing with correct
+     * attributes, mark for update a region containing the cursor
+     * (usually 2x2 character cells joined by almost a full line o
+     * character cells).
+     *
+     * The renderer should only undraw any pixels outside of the text
+     * window (e.g., ones in borders and hardware cursors).
+     */
     i = scp->mouse_oldpos;
     mark_for_update(scp, i);
     mark_for_update(scp, i);
-    if (i + scp->xsize + 1 < size) {
-	mark_for_update(scp, i + scp->xsize + 1);
-    } else if (i + scp->xsize < size) {
-	mark_for_update(scp, i + scp->xsize);
-    } else if (i + 1 < size) {
-	mark_for_update(scp, i + 1);
-    }
+    cols = 1 + howmany(10 - 1, scp->font_width);	/* up to VGA cursor width 9 */
+    cols = imax(cols, 2);	/* in case it is text mode 2x2 char cells */
+    cols = imin(cols, scp->xsize - i % scp->xsize);
+    rows = 1 + howmany(16 - 1, scp->font_size);	/* up to VGA cursor height 16 */
+    rows = imax(rows, 2);	/* don't bother reducing 3 to 2 if text */
+    rows = imin(rows, scp->ysize - i / scp->xsize);
+    mark_for_update(scp, i + (rows - 1) * scp->xsize + cols - 1);
     scp->status &= ~MOUSE_VISIBLE;
     SC_VIDEO_UNLOCK(scp->sc);
 }