zlib.c, packfile.h,config.mak.uname: deflateBound size coercion

The zlib deflateBound() 'size' variable is 32 bits on Windows, but
64 bits on Linux and hence needs careful selection a-priori of
NO_DEFLATE_BOUND on Windows.

Signed-off-by: Philip Oakley <philipoakley@iee.org>

Author: Philip Oakley

config.mak.uname

@@ -424,6 +424,8 @@ ifeq ($(uname_S),Windows)
 	NO_POSIX_GOODIES = UnfortunatelyYes
 	NATIVE_CRLF = YesPlease
 	DEFAULT_HELP_FORMAT = html
+	NO_DEFLATE_BOUND = YesPlease
+	# the zlib.c deflateBound, compiled for windows, is limited to uLong 32bit sourceLen.
 
 	CC = compat/vcbuild/scripts/clink.pl
 	AR = compat/vcbuild/scripts/lib.pl

zlib.c

@@ -140,6 +140,11 @@ int git_inflate(git_zstream *strm, int flush)
 #define deflateBound(c,s)  ((s) + (((s) + 7) >> 3) + (((s) + 63) >> 6) + 11)
 #endif
 
+
+/*
+ * The zlib deflateBound() 'size' is uLong. Define NO_DEFLATE_BOUND on
+ * Windows where uLong is only 32 bits and would result in data loss.
+ */
 size_t git_deflate_bound(git_zstream *strm, size_t size)
 {
 	return deflateBound(&strm->z, size);