Check pointers before freeing (was getting WARNINGS under MALLOC_DEBUG)

git-svn-id: https://origsvn.digium.com/svn/asterisk/trunk@97825 65c4cc65-6c06-0410-ace0-fbb531ad65f3

main/ast_expr2f.c

@@ -3963,7 +3963,8 @@ void *ast_yyrealloc  (void * ptr, yy_size_t  size , yyscan_t yyscanner)
 
 void ast_yyfree (void * ptr , yyscan_t yyscanner)
 {
-	free( (char *) ptr );	/* see ast_yyrealloc() for (char *) cast */
+	if (ptr)
+		free( (char *) ptr );	/* see ast_yyrealloc() for (char *) cast */
 }
 
 #define YYTABLES_NAME "yytables"

main/cli.c

@@ -135,7 +135,8 @@ static char *complete_fn(const char *word, int state)
 		c += (strlen(ast_config_AST_MODULE_DIR) + 1);
 	if (c)
 		c = ast_strdup(c);
-	free(d);
+	if (d)
+		free(d);
 	
 	return c;
 }