patch 8.2.1135: Vim9: getting a dict member may not work

Problem:    Vim9: getting a dict member may not work.
Solution:   Clear the dict only after copying the item.

src/testdir/test_vim9_expr.vim

@@ -1128,13 +1128,16 @@ def Test_expr7_dict_vim9script()
   CheckScriptFailure(lines, 'E1069:')
 enddef
 
+let g:oneString = 'one'
+
 def Test_expr_member()
   assert_equal(1, g:dict_one.one)
   let d: dict<number> = g:dict_one
   assert_equal(1, d['one'])
 
   # getting the one member should clear the dict after getting the item
   assert_equal('one', #{one: 'one'}.one)
+  assert_equal('one', #{one: 'one'}[g:oneString])
 
   call CheckDefFailure(["let x = g:dict_one.#$!"], 'E1002:')
   call CheckDefExecFailure(["let d: dict<any>", "echo d['a']"], 'E716:')

src/version.c

@@ -754,6 +754,8 @@ static char *(features[]) =
 
 static int included_patches[] =
 {   /* Add new patch number below this line */
+/**/
+    1135,
 /**/
     1134,
 /**/

src/vim9execute.c

@@ -2166,6 +2166,7 @@ call_def_function(
 		    dict_T	*dict;
 		    char_u	*key;
 		    dictitem_T	*di;
+		    typval_T	temp_tv;
 
 		    // dict member: dict is at stack-2, key at stack-1
 		    tv = STACK_TV_BOT(-2);
@@ -2181,10 +2182,14 @@ call_def_function(
 			semsg(_(e_dictkey), key);
 			goto failed;
 		    }
-		    --ectx.ec_stack.ga_len;
 		    clear_tv(tv);
-		    clear_tv(STACK_TV_BOT(-1));
-		    copy_tv(&di->di_tv, STACK_TV_BOT(-1));
+		    --ectx.ec_stack.ga_len;
+		    // Clear the dict after getting the item, to avoid that it
+		    // make the item invalid.
+		    tv = STACK_TV_BOT(-1);
+		    temp_tv = *tv;
+		    copy_tv(&di->di_tv, tv);
+		    clear_tv(&temp_tv);
 		}
 		break;