Use INT_ADD_WRAPV etc. to check integer overflow

* src/alloc.c (xnmalloc, xnrealloc, xpalloc, Fmake_string):
* src/buffer.c (record_overlay_string, overlay_strings):
* src/casefiddle.c (casify_object):
* src/ccl.c (Fccl_execute_on_string):
* src/character.c (char_width, c_string_width, lisp_string_width)
(count_size_as_multibyte, string_escape_byte8):
* src/coding.c (coding_alloc_by_realloc, produce_chars):
* src/data.c (arith_driver):
* src/dispnew.c (realloc_glyph_pool, init_display):
* src/editfns.c (styled_format):
* src/fns.c (Ffillarray):
* src/ftfont.c (ftfont_shape_by_flt):
* src/gnutls.c (gnutls_hex_string):
* src/gtkutil.c (get_utf8_string):
* src/image.c (x_to_xcolors, x_detect_edges, png_load_body):
* src/keymap.c (Fkey_description):
* src/lisp.h (SAFE_ALLOCA_LISP):
* src/term.c (encode_terminal_code):
* src/tparam.c (tparam1):
* src/xselect.c (x_property_data_to_lisp):
* src/xsmfns.c (smc_save_yourself_CB):
* src/xterm.c (x_term_init):
When checking for integer overflow, prefer INT_MULTIPLY_WRAPV to
more-complicated code involving division and/or
INT_MULTIPLY_OVERFLOW, and similarly for INT_ADD_WRAPV and
subtraction and/or INT_ADD_OVERFLOW.
* src/casefiddle.c (casify_object): Simplify multibyte size check.
* src/character.c: Remove some obsolete ‘#ifdef emacs’s.
* src/data.c (arith_driver): Also check for division overflow,
as that’s now possible given that the accumulator can now contain
any Emacs integer.
* src/lisp.h (lisp_word_count): Remove; no longer used.

1 files changed, 3 insertions, 2 deletions

diff --git a/src/xselect.c b/src/xselect.c
index 9d178a50d7a..41bd2bc40de 100644
--- a/src/xselect.c
+++ b/src/xselect.c
@@ -2330,10 +2330,11 @@ x_property_data_to_lisp (struct frame *f, const unsigned char *data,
                          Atom type, int format, unsigned long size)
 {
   ptrdiff_t format_bytes = format >> 3;
-  if (PTRDIFF_MAX / format_bytes < size)
+  ptrdiff_t data_bytes;
+  if (INT_MULTIPLY_WRAPV (size, format_bytes, &data_bytes))
     memory_full (SIZE_MAX);
   return selection_data_to_lisp_data (FRAME_DISPLAY_INFO (f), data,
-                                      size * format_bytes, type, format);
+                                      data_bytes, type, format);
 }
 
 DEFUN ("x-get-atom-name", Fx_get_atom_name,