Fix loader's ability to read the 10.1 release PowerPC ISOs. There appears to

be some kind of problem with the version of makefs used for these disks.
There may be a better way to handle this problem, so I've set the MFC
timer for a fairly long time period.

MFC after:	2 weeks

lib/libstand/cd9660.c

@@ -151,9 +151,14 @@ susp_lookup_record(struct open_file *f, const char *identifier,
 				return (NULL);
 			p = susp_buffer + isonum_733(shc->offset);
 			end = p + isonum_733(shc->length);
-		} else
+		} else {
 			/* Ignore this record and skip to the next. */
 			p += isonum_711(sh->length);
+
+			/* Avoid infinite loops with corrupted file systems */
+			if (isonum_711(sh->length) == 0)
+				return (NULL);
+		}
 	}
 	return (NULL);
 }