patch 8.2.3997: Vim9: not enough testing for extend() and map()

Problem:    Vim9: not enough testing for extend() and map().
Solution:   Add more test cases.  Fix uncovered problems.  Remove unused type
            fields.

src/dict.c

@@ -109,8 +109,6 @@ dict_free_contents(dict_T *d)
     hashtab_free_contents(&d->dv_hashtab);
     free_type(d->dv_type);
     d->dv_type = NULL;
-    free_type(d->dv_decl_type);
-    d->dv_decl_type = NULL;
 }
 
 /*

src/list.c

@@ -271,7 +271,6 @@ list_free_list(list_T  *l)
 	l->lv_used_next->lv_used_prev = l->lv_used_prev;
 
     free_type(l->lv_type);
-    free_type(l->lv_decl_type);
     vim_free(l);
 }
 
@@ -1026,8 +1025,6 @@ flatten_common(typval_T *argvars, typval_T *rettv, int make_copy)
 	// The type will change.
 	free_type(l->lv_type);
 	l->lv_type = NULL;
-	free_type(l->lv_decl_type);
-	l->lv_decl_type = NULL;
     }
     else
     {
@@ -1223,7 +1220,6 @@ list_copy(list_T *orig, int deep, int copyID)
     if (copy != NULL)
     {
 	copy->lv_type = alloc_type(orig->lv_type);
-	copy->lv_decl_type = alloc_type(orig->lv_decl_type);
 	if (copyID != 0)
 	{
 	    // Do this before adding the items, because one of the items may

src/structs.h

@@ -1513,7 +1513,6 @@ struct listvar_S
 	} mat;
     } lv_u;
     type_T	*lv_type;	// current type, allocated by alloc_type()
-    type_T	*lv_decl_type;	// declared type, allocated by alloc_type()
     list_T	*lv_copylist;	// copied list used by deepcopy()
     list_T	*lv_used_next;	// next list in used lists list
     list_T	*lv_used_prev;	// previous list in used lists list
@@ -1578,7 +1577,6 @@ struct dictvar_S
     int		dv_copyID;	// ID used by deepcopy()
     hashtab_T	dv_hashtab;	// hashtab that refers to the items
     type_T	*dv_type;	// current type, allocated by alloc_type()
-    type_T	*dv_decl_type;	// declared type, allocated by alloc_type()
     dict_T	*dv_copydict;	// copied dict used by deepcopy()
     dict_T	*dv_used_next;	// next dict in used dicts list
     dict_T	*dv_used_prev;	// previous dict in used dicts list

src/testdir/test_vim9_builtin.vim

@@ -979,6 +979,10 @@ def Test_extend_arg_types()
       var res: list<dict<any>>
       extend(res, mapnew([1, 2], (_, v) => ({})))
       assert_equal([{}, {}], res)
+
+      var dany: dict<any> = {a: 0}
+      dany->extend({b: 'x'})
+      assert_equal({a: 0, b: 'x'}, dany)
   END
   CheckDefAndScriptSuccess(lines)
 
@@ -2151,9 +2155,29 @@ def Test_map()
   CheckDefAndScriptFailure(['map(1, "1")'], ['E1013: Argument 1: type mismatch, expected list<any> but got number', 'E1251: List, Dictionary, Blob or String required for argument 1'])
 
   # type of dict remains dict<any> even when type of values changes
+  # same for list
+  var lines =<< trim END
       var d: dict<any> = {a: 0}
       d->map((k, v) => true)
       d->map((k, v) => 'x')
+      assert_equal({a: 'x'}, d)
+
+      d = {a: 0}
+      g:gd = d
+      map(g:gd, (k, v) => true)
+      assert_equal({a: true}, g:gd)
+
+      var l: list<any> = [0]
+      l->map((k, v) => true)
+      l->map((k, v) => 'x')
+      assert_equal(['x'], l)
+
+      l = [1]
+      g:gl = l
+      map(g:gl, (k, v) => true)
+      assert_equal([true], g:gl)
+  END
+  CheckDefAndScriptSuccess(lines)
 enddef
 
 def Test_map_failure()
@@ -2175,6 +2199,13 @@ def Test_map_failure()
   CheckScriptFailure(lines, 'E1013:')
   au! BufReadPost
   delete('Xtmpfile')
+
+  lines =<< trim END
+      var d: dict<number> = {a: 1}
+      g:gd = d
+      map(g:gd, (k, v) => true)
+  END
+  CheckDefExecAndScriptFailure(lines, 'E1012: Type mismatch; expected number but got bool')
 enddef
 
 def Test_map_function_arg()

src/testdir/test_vim9_disassemble.vim

@@ -455,6 +455,7 @@ def Test_disassemble_list_assign()
         '\d\+ CHECKTYPE string stack\[-1\] arg 2\_s*' ..
         '\d\+ STORE $1\_s*' ..
         '\d\+ SLICE 2\_s*' ..
+        '\d\+ SETTYPE list<any>\_s*' ..
         '\d\+ STORE $2\_s*' ..
         '\d\+ RETURN void',
         res)

src/version.c

@@ -750,6 +750,8 @@ static char *(features[]) =
 
 static int included_patches[] =
 {   /* Add new patch number below this line */
+/**/
+    3997,
 /**/
     3996,
 /**/

src/vim9compile.c

@@ -2279,14 +2279,12 @@ compile_assignment(char_u *arg, exarg_T *eap, cmdidx_T cmdidx, cctx_T *cctx)
 		// ":const var": lock the value, but not referenced variables
 		generate_LOCKCONST(cctx);
 
-	    if (is_decl
+	    if ((lhs.lhs_type->tt_type == VAR_DICT
-		    && (lhs.lhs_type->tt_type == VAR_DICT
 					  || lhs.lhs_type->tt_type == VAR_LIST)
 		    && lhs.lhs_type->tt_member != NULL
 		    && lhs.lhs_type->tt_member != &t_unknown)
 		// Set the type in the list or dict, so that it can be checked,
-		// also in legacy script.  Not for "list<any> = val", then the
+		// also in legacy script.
-		// type of "val" is used.
 		generate_SETTYPE(cctx, lhs.lhs_type);
 
 	    if (!skip_store && generate_store_lhs(cctx, &lhs,