patch 8.2.3429: leaking memory when assigning to list or dict

Problem:    Leaking memory when assigning to list or dict.
Solution:   Free the list or dict type before overwriting it.

src/evalvars.c

@@ -3462,9 +3462,21 @@ set_var_const(
     if (vim9script && type != NULL)
     {
 	if (type->tt_type == VAR_DICT && dest_tv->vval.v_dict != NULL)
-	    dest_tv->vval.v_dict->dv_type = alloc_type(type);
+	{
+	    if (dest_tv->vval.v_dict->dv_type != type)
+	    {
+		free_type(dest_tv->vval.v_dict->dv_type);
+		dest_tv->vval.v_dict->dv_type = alloc_type(type);
+	    }
+	}
 	else if (type->tt_type == VAR_LIST && dest_tv->vval.v_list != NULL)
-	    dest_tv->vval.v_list->lv_type = alloc_type(type);
+	{
+	    if (dest_tv->vval.v_list->lv_type != type)
+	    {
+		free_type(dest_tv->vval.v_list->lv_type);
+		dest_tv->vval.v_list->lv_type = alloc_type(type);
+	    }
+	}
     }
 
     // ":const var = value" locks the value

src/version.c

@@ -755,6 +755,8 @@ static char *(features[]) =
 
 static int included_patches[] =
 {   /* Add new patch number below this line */
+/**/
+    3429,
 /**/
     3428,
 /**/

src/vim9type.c

@@ -258,7 +258,7 @@ func_type_add_arg_types(
 typval2type_int(typval_T *tv, int copyID, garray_T *type_gap, int do_member)
 {
     type_T  *type;
-    type_T  *member_type = &t_any;
+    type_T  *member_type = NULL;
     int	    argcount = 0;
     int	    min_argcount = 0;
 
@@ -268,6 +268,8 @@ typval2type_int(typval_T *tv, int copyID, garray_T *type_gap, int do_member)
 	return &t_bool;
     if (tv->v_type == VAR_STRING)
 	return &t_string;
+    if (tv->v_type == VAR_BLOB)
+	return &t_blob;
 
     if (tv->v_type == VAR_LIST)
     {