Constrain window box sizes (Bug#16649).

* xdisp.c (window_box_width): Don't return less than zero.
(window_box_left_offset, window_box_right_offset): Don't return
more than the window's pixel width.

diff --git a/src/ChangeLog b/src/ChangeLog
index 9efaff3d20c47233aa888663f25865699e42a362..07a6aaaf871352878ac59012e5799d12431e9310 100644 (file)
--- a/src/ChangeLog
+++ b/src/ChangeLog
@@ -1,3 +1,10 @@
+2014-02-07  Martin Rudalics  <rudalics@gmx.at>
+
+       Constrain window box sizes (Bug#16649).
+       * xdisp.c (window_box_width): Don't return less than zero.
+       (window_box_left_offset, window_box_right_offset): Don't return
+       more than the window's pixel width.
+
 2014-02-07  Glenn Morris  <rgm@gnu.org>
 
        * nsterm.m (syms_of_nsterm): Doc fix.

diff --git a/src/xdisp.c b/src/xdisp.c
index 980e905b0974a06086142426dc7010af2a041f0f..430551b2b68b9ce89188a833e76373e94b3c34a0 100644 (file)
--- a/src/xdisp.c
+++ b/src/xdisp.c
@@ -1019,23 +1019,25 @@ window_text_bottom_y (struct window *w)
 int
 window_box_width (struct window *w, enum glyph_row_area area)
 {
-  int pixels = w->pixel_width;
+  int width = w->pixel_width;
 
   if (!w->pseudo_window_p)
     {
-      pixels -= WINDOW_SCROLL_BAR_AREA_WIDTH (w);
-      pixels -= WINDOW_RIGHT_DIVIDER_WIDTH (w);
+      width -= WINDOW_SCROLL_BAR_AREA_WIDTH (w);
+      width -= WINDOW_RIGHT_DIVIDER_WIDTH (w);
 
       if (area == TEXT_AREA)
-       pixels -= (WINDOW_MARGINS_WIDTH (w)
+       width -= (WINDOW_MARGINS_WIDTH (w)
                   + WINDOW_FRINGES_WIDTH (w));
       else if (area == LEFT_MARGIN_AREA)
-       pixels = WINDOW_LEFT_MARGIN_WIDTH (w);
+       width = WINDOW_LEFT_MARGIN_WIDTH (w);
       else if (area == RIGHT_MARGIN_AREA)
-       pixels = WINDOW_RIGHT_MARGIN_WIDTH (w);
+       width = WINDOW_RIGHT_MARGIN_WIDTH (w);
     }
 
-  return pixels;
+  /* With wide margins, fringes, etc. we might end up with a negative
+     width, correct that here.  */
+  return max (0, width);
 }
 
 
@@ -1115,7 +1117,8 @@ window_box_left_offset (struct window *w, enum glyph_row_area area)
           && WINDOW_HAS_FRINGES_OUTSIDE_MARGINS (w))
     x += WINDOW_LEFT_FRINGE_WIDTH (w);
 
-  return x;
+  /* Don't return more than the window's pixel width.  */
+  return min (x, w->pixel_width);
 }
 
 
@@ -1126,7 +1129,9 @@ window_box_left_offset (struct window *w, enum glyph_row_area area)
 int
 window_box_right_offset (struct window *w, enum glyph_row_area area)
 {
-  return window_box_left_offset (w, area) + window_box_width (w, area);
+  /* Don't return more than the window's pixel width.  */
+  return min (window_box_left_offset (w, area) + window_box_width (w, area),
+             w->pixel_width);
 }
 
 /* Return the frame-relative coordinate of the left edge of display