vcs-svn: suppress -Wtype-limits warning

On 32-bit architectures with 64-bit file offsets, gcc 4.3 and earlier
produce the following warning:

	    CC vcs-svn/sliding_window.o
	vcs-svn/sliding_window.c: In function `check_overflow':
	vcs-svn/sliding_window.c:36: warning: comparison is always false \
	    due to limited range of data type

The warning appears even when gcc is run without any warning flags
(PR12963).  In later versions it can be reproduced with -Wtype-limits,
which is implied by -Wextra.

On 64-bit architectures it really is possible for a size_t not to be
representable as an off_t so the check being warned about is not
actually redundant.  But even false positives are distracting.  Avoid
the warning by making the "len" argument to check_overflow a
uintmax_t; no functional change intended.

Reported-by: Ramsay Jones <ramsay@ramsay1.demon.co.uk>
Signed-off-by: Jonathan Nieder <jrnieder@gmail.com>

vcs-svn/sliding_window.c

@@ -31,15 +31,15 @@ static int read_to_fill_or_whine(struct line_buffer *file,
 	return 0;
 }
 
-static int check_offset_overflow(off_t offset, size_t len)
+static int check_offset_overflow(off_t offset, uintmax_t len)
 {
 	if (len > maximum_signed_value_of_type(off_t))
 		return error("unrepresentable length in delta: "
-				"%"PRIuMAX" > OFF_MAX", (uintmax_t) len);
+				"%"PRIuMAX" > OFF_MAX", len);
 	if (signed_add_overflows(offset, (off_t) len))
 		return error("unrepresentable offset in delta: "
 				"%"PRIuMAX" + %"PRIuMAX" > OFF_MAX",
-				(uintmax_t) offset, (uintmax_t) len);
+				(uintmax_t) offset, len);
 	return 0;
 }