Check for buffer and string overflow more precisely.

* buffer.h (BUF_BYTES_MAX): New macro.
* lisp.h (STRING_BYTES_MAX): New macro.
* alloc.c (Fmake_string):
* character.c (string_escape_byte8):
* coding.c (coding_alloc_by_realloc):
* doprnt.c (doprnt):
* editfns.c (Fformat):
* eval.c (verror):
Use STRING_BYTES_MAX, not MOST_POSITIVE_FIXNUM,
since they may not be the same number.
* editfns.c (Finsert_char):
* fileio.c (Finsert_file_contents):
Likewise for BUF_BYTES_MAX.

1 files changed, 2 insertions, 2 deletions

diff --git a/src/character.c b/src/character.c
index 34e69da9cc5..170952619e7 100644
--- a/src/character.c
+++ b/src/character.c
@@ -838,7 +838,7 @@ string_escape_byte8 (Lisp_Object string)
   if (multibyte)
     {
       if ((MOST_POSITIVE_FIXNUM - nchars) / 3 < byte8_count
-          || (MOST_POSITIVE_FIXNUM - nbytes) / 2 < byte8_count)
+          || (STRING_BYTES_MAX - nbytes) / 2 < byte8_count)
         string_overflow ();
 
       /* Convert 2-byte sequence of byte8 chars to 4-byte octal.  */
@@ -847,7 +847,7 @@ string_escape_byte8 (Lisp_Object string)
     }
   else
     {
-      if ((MOST_POSITIVE_FIXNUM - nchars) / 3 < byte8_count)
+      if ((STRING_BYTES_MAX - nchars) / 3 < byte8_count)
         string_overflow ();
 
       /* Convert 1-byte sequence of byte8 chars to 4-byte octal.  */