commit bash-20150918 snapshot

builtins/exec.def

@@ -142,6 +142,7 @@ exec_builtin (list)
 #endif /* RESTRICTED_SHELL */
 
   args = strvec_from_word_list (list, 1, 0, (int *)NULL);
+  env = (char **)0;
 
   /* A command with a slash anywhere in its name is not looked up in $PATH. */
   command = absolute_program (args[0]) ? args[0] : search_for_command (args[0], 1);
@@ -193,7 +194,10 @@ exec_builtin (list)
     adjust_shell_level (-1);
 
   if (cleanenv)
-    env = (char **)NULL;
+    {
+      env = strvec_create (1);
+      env[0] = (char *)0;
+    }
   else
     {	
       maybe_make_export_env ();
@@ -242,6 +246,9 @@ failed_exec:
   if (args)
     strvec_dispose (args);
 
+  if (env && env != export_env)
+    strvec_dispose (env);
+
   initialize_traps ();
   initialize_signals (1);