--- a/newgrf.c	Sat Feb 24 01:47:26 2007 +0000
+++ b/newgrf.c	Sat Feb 24 16:46:36 2007 +0000
@@ -1479,6 +1479,11 @@
 	uint8 numinfo;
 	uint8 index;
 
+	if (len == 1) {
+		grfmsg(8, "Silently ignoring one-byte special sprite 0x00");
+		return;
+	}
+
 	check_length(len, 6, "SafeChangeInfo");
 	buf++;
 	feature  = grf_load_byte(&buf);