(coordinates_in_window): Don't report on margin area if its width is zero.

1 files changed, 16 insertions, 4 deletions

diff --git a/src/window.c b/src/window.c
index 21fb9d53e59..e88873528c8 100644
--- a/src/window.c
+++ b/src/window.c
@@ -534,6 +534,7 @@ coordinates_in_window (w, x, y)
   /* The width of the area where the vertical line can be dragged.
      (Between mode lines for instance.  */
   int grabbable_width = ux;
+  int lmargin_width = 0, rmargin_width = 0;
 
   if (*x < x0 || *x >= x1)
     return ON_NOTHING;
@@ -628,9 +629,14 @@ coordinates_in_window (w, x, y)
         }
       else
         {
-          if (*x <= window_box_right (w, LEFT_MARGIN_AREA))
+          lmargin_width = window_box_width (w, LEFT_MARGIN_AREA);
+          rmargin_width = window_box_width (w, RIGHT_MARGIN_AREA);
+          /* You can never be on a margin area if its width is zero.  */
+          if (lmargin_width
+              && *x <= window_box_right (w, LEFT_MARGIN_AREA))
             part = ON_LEFT_MARGIN;
-          else if (*x >= window_box_left (w, RIGHT_MARGIN_AREA))
+          else if (rmargin_width
+                   && *x >= window_box_left (w, RIGHT_MARGIN_AREA))
             part = ON_RIGHT_MARGIN;
           else
             {
@@ -665,9 +671,15 @@ coordinates_in_window (w, x, y)
         }
       else
         {
-          if (*x <= window_box_right (w, LEFT_MARGIN_AREA))
+          lmargin_width = window_box_width (w, LEFT_MARGIN_AREA);
+          rmargin_width = window_box_width (w, RIGHT_MARGIN_AREA);
+          /* You can never be on a margin area if its width is zero.
+             This is especially important for character terminals.  */
+          if (lmargin_width
+              && *x <= window_box_right (w, LEFT_MARGIN_AREA))
             part = ON_LEFT_MARGIN;
-          else if (*x >= window_box_left (w, RIGHT_MARGIN_AREA))
+          else if (rmargin_width
+                   && *x >= window_box_left (w, RIGHT_MARGIN_AREA))
             part = ON_RIGHT_MARGIN;
           else
             {