--- OLD/pnm/pnmrotate.c	Thu Jan  1 00:00:00 1970
+++ NEW/pnm/pnmrotate.c	Thu Jan  1 00:00:00 1970
@@ -47,6 +47,7 @@
     antialias = 1;
 
     if ( argn < argc && argv[argn][0] == '-' && argv[argn][1] != '\0' &&
+	 (argv[argn][1] != '.') &&
 	 ( argv[argn][1] < '0' || argv[argn][1] > '9' ) )
         {
         if ( pm_keymatch( argv[argn], "-antialias", 2 ) )