* xfns.c (compute_tip_xy): Handle negative dx and dy.

* w32fns.c (compute_tip_xy): Ditto

* macfns.c (compute_tip_xy): Ditto

1 files changed, 4 insertions, 0 deletions

diff --git a/src/xfns.c b/src/xfns.c
index 667b1411d1c..ead4d76c710 100644
--- a/src/xfns.c
+++ b/src/xfns.c
@@ -4940,6 +4940,8 @@ compute_tip_xy (f, parms, dx, dy, width, height, root_x, root_y)
 
   if (INTEGERP (top))
     *root_y = XINT (top);
+  else if (*root_y + XINT (dy) <= 0)
+    *root_y = 0; /* Can happen for negative dy */
   else if (*root_y + XINT (dy) + height <= FRAME_X_DISPLAY_INFO (f)->height)
     /* It fits below the pointer */
       *root_y += XINT (dy);
@@ -4952,6 +4954,8 @@ compute_tip_xy (f, parms, dx, dy, width, height, root_x, root_y)
 
   if (INTEGERP (left))
     *root_x = XINT (left);
+  else if (*root_x + XINT (dx) <= 0)
+    *root_x = 0; /* Can happen for negative dx */
   else if (*root_x + XINT (dx) + width <= FRAME_X_DISPLAY_INFO (f)->width)
     /* It fits to the right of the pointer.  */
     *root_x += XINT (dx);