* fileio.c: Fix bugs with large file offsets.

The previous code assumed that file offsets (off_t values) fit in
EMACS_INT variables, which is not true on typical 32-bit hosts.
The code messed up by falsely reporting buffer overflow in cases
such as (insert-file-contents "big" nil 1 2) into an empty buffer
when "big" contains more than 2**29 bytes, even though this
inserts just one byte and does not overflow the buffer.
(Finsert_file_contents): Store file offsets as off_t
values, not as EMACS_INT values.  Check for overflow when
converting between EMACS_INT and off_t.  When checking for
buffer overflow or for overlap, take the offsets into account.
Don't use EMACS_INT for small values where int suffices.
When checking for overlap, fix a typo: ZV was used where
ZV_BYTE was intended.
(Fwrite_region): Don't assume off_t fits into 'long'.
* buffer.h (struct buffer.modtime_size): Now off_t, not EMACS_INT.

1 files changed, 1 insertions, 1 deletions

diff --git a/src/buffer.h b/src/buffer.h
index 06864dd5789..c50cfe56c77 100644
--- a/src/buffer.h
+++ b/src/buffer.h
@@ -559,7 +559,7 @@ struct buffer
      is still the same (since it's rounded up to seconds) but we're actually
      not up-to-date.  -1 means the size is unknown.  Only meaningful if
      modtime is actually set.  */
-  EMACS_INT modtime_size;
+  off_t modtime_size;
   /* The value of text->modiff at the last auto-save.  */
   int auto_save_modified;
   /* The value of text->modiff at the last display error.