(copy_stream): avoid calling mmap with `len == 0'. Some mmap:s rather

dislike that (Solaris) and some munmap get grumpy later.


git-svn-id: svn://svn.h5l.se/heimdal/trunk/heimdal@6803 ec53bebd-3082-4978-b11e-865c3cabbd6b

appl/ftp/ftp/ftp.c

@@ -567,6 +567,11 @@ copy_stream (FILE * from, FILE * to)
 #endif
 
     if (fstat (fileno (from), &st) == 0 && S_ISREG (st.st_mode)) {
+	/*
+	 * mmap zero bytes has potential of loosing, don't do it.
+	 */
+	if (st.st_size == 0)
+	    return 0;
 	chunk = mmap (0, st.st_size, PROT_READ, MAP_SHARED, fileno (from), 0);
 	if (chunk != (void *) MAP_FAILED) {
 	    int res;