Minor integer overflow fixes.

* window.c (Fset_window_new_pixel, grow_mini_window):
* xdisp.c (Fwindow_text_pixel_size):
Avoid undefined behavior on signed integer overflow.
* xfns.c (x_set_mouse_color):
Check that drag shape fits in 'unsigned', since that's what X wants.

4 files changed, 19 insertions, 6 deletions

diff --git a/src/ChangeLog b/src/ChangeLog
index a5c6668c551..d26a3798b09 100644
--- a/src/ChangeLog
+++ b/src/ChangeLog
@@ -1,3 +1,12 @@
+2013-12-03  Paul Eggert  <eggert@cs.ucla.edu>
+
+        Minor integer overflow fixes.
+        * window.c (Fset_window_new_pixel, grow_mini_window):
+        * xdisp.c (Fwindow_text_pixel_size):
+        Avoid undefined behavior on signed integer overflow.
+        * xfns.c (x_set_mouse_color):
+        Check that drag shape fits in 'unsigned', since that's what X wants.
+
 2013-12-02  Eli Zaretskii  <eliz@gnu.org>
 
         Improve reporting of fatal exception on MS-Windows.
diff --git a/src/window.c b/src/window.c
index a28449ba1db..e2770410bce 100644
--- a/src/window.c
+++ b/src/window.c
@@ -3646,8 +3646,10 @@ Note: This function does not operate on any child windows of WINDOW.  */)
   (Lisp_Object window, Lisp_Object size, Lisp_Object add)
 {
   struct window *w = decode_valid_window (window);
+  EMACS_INT size_max = (min (INT_MAX, MOST_POSITIVE_FIXNUM)
+                        - (NILP (add) ? 0 : XINT (w->new_pixel)));
 
-  CHECK_NUMBER (size);
+  CHECK_RANGED_INTEGER (size, 0, size_max);
   if (NILP (add))
     wset_new_pixel (w, size);
   else
@@ -4556,12 +4558,14 @@ grow_mini_window (struct window *w, int delta, bool pixelwise)
 
           if (pixelwise)
             {
-              pixel_height = -XINT (height);
+              pixel_height = min (-XINT (height), INT_MAX - w->pixel_height);
               line_height = pixel_height / FRAME_LINE_HEIGHT (f);
             }
           else
             {
-              line_height = -XINT (height);
+              line_height = min (-XINT (height),
+                                 ((INT_MAX - w->pixel_height)
+                                  / FRAME_LINE_HEIGHT (f)));
               pixel_height = line_height * FRAME_LINE_HEIGHT (f);
             }
 
diff --git a/src/xdisp.c b/src/xdisp.c
index b52c89a7556..d1c8cd3cf28 100644
--- a/src/xdisp.c
+++ b/src/xdisp.c
@@ -9567,7 +9567,7 @@ include the height of any of these lines in the return value.  */)
   if (!NILP (y_limit))
     {
       CHECK_NUMBER (y_limit);
-      max_y = XINT (y_limit);
+      max_y = min (XINT (y_limit), INT_MAX);
     }
 
   itdata = bidi_shelve_cache ();
@@ -9580,7 +9580,7 @@ include the height of any of these lines in the return value.  */)
   else
     {
       CHECK_NUMBER (x_limit);
-      it.last_visible_x = XINT (x_limit);
+      it.last_visible_x = min (XINT (x_limit), INFINITY);
       /* Actually, we never want move_it_to stop at to_x.  But to make
          sure that move_it_in_display_line_to always moves far enough,
          we set it to INT_MAX and specify MOVE_TO_X.  */
diff --git a/src/xfns.c b/src/xfns.c
index bd4a6a62db6..2830a79972c 100644
--- a/src/xfns.c
+++ b/src/xfns.c
@@ -680,7 +680,7 @@ x_set_mouse_color (struct frame *f, Lisp_Object arg, Lisp_Object oldval)
 
   if (!NILP (Vx_window_horizontal_drag_shape))
     {
-      CHECK_NUMBER (Vx_window_horizontal_drag_shape);
+      CHECK_TYPE_RANGED_INTEGER (unsigned, Vx_window_horizontal_drag_shape);
       horizontal_drag_cursor
         = XCreateFontCursor (dpy, XINT (Vx_window_horizontal_drag_shape));
     }