diff -uNr tmp/magic-7.1/textio/txInput.c other/magic-7.1/textio/txInput.c
--- tmp/magic-7.1/textio/txInput.c	2002-10-02 16:36:25.000000000 -0500
+++ other/magic-7.1/textio/txInput.c	2002-10-02 16:36:59.000000000 -0500
@@ -579,7 +579,7 @@
 
   free(line);
 
-  matches = (completion_func) ? completion_matches(text, completion_func) : (char **)NULL;
+  matches = (completion_func != NULL) ? completion_matches(text, completion_func) : (char **)NULL;
 
   /* If we match nothing, inhibit any matching, except when matching files */
   rl_attempted_completion_over = (matches == (char **)NULL &&