main/cli: Do not attempt to show CDR data for internal channels

Internal channels don't have CDRs. Querying the CDR engine for their variables
will make it cranky.
........

Merged revisions 422506 from http://svn.asterisk.org/svn/asterisk/branches/12
........

Merged revisions 422507 from http://svn.asterisk.org/svn/asterisk/branches/13


git-svn-id: https://origsvn.digium.com/svn/asterisk/trunk@422524 65c4cc65-6c06-0410-ace0-fbb531ad65f3

main/cli.c

@@ -1662,7 +1662,8 @@ static char *handle_showchan(struct ast_cli_entry *e, int cmd, struct ast_cli_ar
 		ast_str_append(&output, 0, "%s=%s\n", ast_var_name(var), ast_var_value(var));
 	}
 
-	if (ast_cdr_serialize_variables(ast_channel_name(chan), &obuf, '=', '\n')) {
+	if (!(ast_channel_tech(chan)->properties & AST_CHAN_TP_INTERNAL)
+		&& ast_cdr_serialize_variables(ast_channel_name(chan), &obuf, '=', '\n')) {
 		ast_str_append(&output, 0, "  CDR Variables:\n%s\n", ast_str_buffer(obuf));
 	}