Make --whole-file the default when source and target are on the local machine.

main.c

@@ -581,6 +581,7 @@ static int start_client(int argc, char *argv[])
 	extern int am_sender;
 	extern char *shell_cmd;
 	extern int rsync_port;
+	extern int whole_file;
 	char *argv0 = strdup(argv[0]);
 
 	if (strncasecmp(URL_PREFIX, argv0, strlen(URL_PREFIX)) == 0) {
@@ -627,6 +628,8 @@ static int start_client(int argc, char *argv[])
 		p = find_colon(argv[argc-1]);
 		if (!p) {
 			local_server = 1;
+			/* disable "rsync algorithm" when both sides local */
+			whole_file = 1;
 		} else if (p[1] == ':') {
 			*p = 0;
 			return start_socket_client(argv[argc-1], p+2, argc-1, argv);

rsync.yo

 mailto(rsync-bugs@samba.org)
-manpage(rsync)(1)(3 Mar 2001)()()
+manpage(rsync)(1)(29 May 2001)()()
 manpagename(rsync)(faster, flexible replacement for rcp)
 manpagesynopsis()
 
@@ -395,8 +395,11 @@ are in the list of files being sent.
 This option can be quite slow, so only use it if you need it.
 
 dit(bf(-W, --whole-file)) With this option the incremental rsync algorithm
-is  not used  and  the whole file is sent as-is instead. This may be
-useful when using rsync with a local machine.
+is not used and the whole file is sent as-is instead.  The transfer may be
+faster if this option is used when the bandwidth between the source and
+target machines is higher than the bandwidth to disk (especially when the
+"disk" is actually a networked file system).  This is the default when both
+the source and target are on the local machine.
 
 dit(bf(-p, --perms)) This option causes rsync to update the remote
 permissions to be the same as the local permissions.