(make_gap_larger): Don't make as many assumptions about the

representation of Lisp integers.
Reported by MJ Chan <mjchan.inbox@gmail.com>.

2 files changed, 29 insertions, 23 deletions

diff --git a/src/ChangeLog b/src/ChangeLog
index 713bfe7d7d6..474bc2e0e26 100644
--- a/src/ChangeLog
+++ b/src/ChangeLog
@@ -1,3 +1,9 @@
+2009-11-19  Stefan Monnier  <monnier@iro.umontreal.ca>
+
+        * insdel.c (make_gap_larger): Don't make as many assumptions about the
+        representation of Lisp integers.
+        Reported by MJ Chan <mjchan.inbox@gmail.com>.
+
 2009-11-17  Andreas Schwab  <schwab@linux-m68k.org>
 
         * lisp.h: Remove declaration of Ffont_get_system_font.
@@ -6,8 +12,8 @@
 
 2009-11-17  Jan Djärv  <jan.h.d@swipnet.se>
 
-        * xsettings.c (something_changedCB, Ffont_get_system_font): Check
-        use_system_font.
+        * xsettings.c (something_changedCB, Ffont_get_system_font):
+        Check use_system_font.
         (syms_of_xsettings): DEFVAR font-use-system-font.
 
 2009-11-17  Andreas Schwab  <schwab@linux-m68k.org>
@@ -18,10 +24,10 @@
 
 2009-11-17  Jan Djärv  <jan.h.d@swipnet.se>
 
-        * xftfont.c (xftfont_fix_match): Older versions of fontconfig does
+        * xftfont.c (xftfont_fix_match): Older versions of fontconfig do
         not have FC_LCD_*.  #define them if not there.
 
-        * xsettings.c (parse_xft_settings, apply_xft_settings): Ditto
+        * xsettings.c (parse_xft_settings, apply_xft_settings): Ditto.
 
         * xterm.h (struct x_display_info): Add atoms and Window for xsettings.
 
@@ -36,10 +42,11 @@
 
         * xfont.c (xfont_driver): Initialize all members.
 
-        * xfns.c (x_default_font_parameter): Try font from Ffont_get_system_font.
+        * xfns.c (x_default_font_parameter):
+        Try font from Ffont_get_system_font.
         Do not get font from x_default_parameter if we got one from
         Ffont_get_system_font.
-        (Fx_select_font): Get the defaut font name from :name of FRAME_FONT (f).
+        (Fx_select_font): Get the defaut font name from :name of FRAME_FONT(f).
 
         * w32font.c (w32font_driver): Initialize all members.
 
@@ -47,22 +54,22 @@
 
         * lisp.h: Declare syms_of_xsettings.
 
-        * keyboard.c (kbd_buffer_get_event, make_lispy_event): Handle 
-        CONFIG_CHANGED_EVENT.
+        * keyboard.c (kbd_buffer_get_event, make_lispy_event):
+        Handle CONFIG_CHANGED_EVENT.
 
         * ftfont.c (ftfont_filter_properties): New function.
 
         * frame.c (x_set_font): Remove unused variable lval.
 
-        * font.h (struct font_driver): filter_properties is new.
+        * font.h (struct font_driver): Add filter_properties.
 
         * font.c (font_put_extra): Don't return if val is nil, it means
         boolean option is off.
         (font_parse_fcname): Collect all extra properties in extra_props
         and call filter_properties for all drivers with extra_props and
         font as parameter.
-        (font_open_entity): Do not use cache, it does not pick up new fontconfig
-        settings like hinting.
+        (font_open_entity): Do not use cache, it does not pick up new
+        fontconfig settings like hinting.
         (font_load_for_lface): If spec had a name in it, store it in entity.
 
         * emacs.c (main): Call syms_of_xsettings
@@ -89,8 +96,7 @@
 
 2009-11-14  Andreas Schwab  <schwab@linux-m68k.org>
 
-        * Makefile.in: Ignore errors from mkdir when creating deps
-        directory.
+        * Makefile.in: Ignore errors from mkdir when creating deps directory.
 
 2009-11-14  Jan Djärv  <jan.h.d@swipnet.se>
 
diff --git a/src/insdel.c b/src/insdel.c
index bdd450558bd..0faf3c07227 100644
--- a/src/insdel.c
+++ b/src/insdel.c
@@ -512,16 +512,16 @@ make_gap_larger (EMACS_INT nbytes_added)
   /* If we have to get more space, get enough to last a while.  */
   nbytes_added += 2000;
 
-  /* Don't allow a buffer size that won't fit in an int
-     even if it will fit in a Lisp integer.
-     That won't work because so many places use `int'.
-
-     Make sure we don't introduce overflows in the calculation.  */
-
-  if (Z_BYTE - BEG_BYTE + GAP_SIZE
-      >= (((EMACS_INT) 1 << (min (VALBITS, BITS_PER_INT) - 1)) - 1
-          - nbytes_added))
-    error ("Buffer exceeds maximum size");
+  { EMACS_INT total_size = Z_BYTE - BEG_BYTE + GAP_SIZE + nbytes_added;
+    if (total_size < 0
+        /* Don't allow a buffer size that won't fit in a Lisp integer.  */
+        || total_size != XINT (make_number (total_size))
+        /* Don't allow a buffer size that won't fit in an int
+           even if it will fit in a Lisp integer.
+           That won't work because so many places still use `int'.  */
+        || total_size != (EMACS_INT) (int) total_size)
+      error ("Buffer exceeds maximum size");
+  }
 
   enlarge_buffer_text (current_buffer, nbytes_added);