Index: main/cli.c
===================================================================
--- main/cli.c	(revision 375799)
+++ main/cli.c	(working copy)
@@ -1871,10 +1871,16 @@
 	return 0;
 }
 
+static void cli_shutdown(void)
+{
+	ast_cli_unregister_multiple(cli_cli, ARRAY_LEN(cli_cli));
+}
+
 /*! \brief initialize the _full_cmd string in * each of the builtins. */
 void ast_builtins_init(void)
 {
 	ast_cli_register_multiple(cli_cli, ARRAY_LEN(cli_cli));
+	ast_register_atexit(cli_shutdown);
 }
 
 /*!
@@ -2039,6 +2045,17 @@
 	return cmdline;
 }
 
+static int cli_is_registered(struct ast_cli_entry *e)
+{
+	struct ast_cli_entry *cur = NULL;
+	while ((cur = cli_next(cur))) {
+		if (cur==e) {
+			return 1;
+		}
+	}
+	return 0;
+}
+
 static int __ast_cli_unregister(struct ast_cli_entry *e, struct ast_cli_entry *ed)
 {
 	if (e->inuse) {
@@ -2070,6 +2087,14 @@
 	char **dst = (char **)e->cmda;	/* need to cast as the entry is readonly */
 	char *s;
 
+	AST_RWLIST_WRLOCK(&helpers);
+
+	if (cli_is_registered(e)) {
+		ast_log(LOG_WARNING, "Command '%s' already registered (the same ast_cli_entry)\n", S_OR(e->_full_cmd, e->command));
+		ret = 0;  /* report success */
+		goto done;
+	}
+
 	memset(&a, '\0', sizeof(a));
 	e->handler(e, CLI_INIT, &a);
 	/* XXX check that usage and command are filled up */
@@ -2084,11 +2109,10 @@
 		s = ast_skip_blanks(s);
 	}
 	*dst++ = NULL;
-	
-	AST_RWLIST_WRLOCK(&helpers);
-	
+
 	if (find_cli(e->cmda, 1)) {
 		ast_log(LOG_WARNING, "Command '%s' already registered (or something close enough)\n", S_OR(e->_full_cmd, e->command));
+		ret = -2;
 		goto done;
 	}
 	if (set_full_cmd(e))
@@ -2112,6 +2136,12 @@
 
 done:
 	AST_RWLIST_UNLOCK(&helpers);
+	if (ret) {
+		if (ret==-1)
+			ast_log(LOG_WARNING, "Error registering CLI Command '%s'\n", S_OR(e->_full_cmd, e->command));
+		ast_free(e->command);
+		e->command = NULL;
+	}
 
 	return ret;
 }