# HG changeset patch
# User Bram Moolenaar <Bram@vim.org>
# Date 1622575803 -7200
# Node ID 3907cf9be7455b2fecea3bfe7ba1519c4ad8d574
# Parent  771755ad13d26ed3f7abcfe371bc2d430ee06e39
patch 8.2.2920: still a way to shadow a builtin function

Commit: https://github.com/vim/vim/commit/6f1d2aa437744a7cb0206fdaa543a788c5a56c79
Author: Bram Moolenaar <Bram@vim.org>
Date:   Tue Jun 1 21:21:55 2021 +0200

    patch 8.2.2920: still a way to shadow a builtin function

    Problem:    Still a way to shadow a builtin function. (Yasuhiro Matsumoto)
    Solution:   Check the key when using extend(). (issue https://github.com/vim/vim/issues/8302)

diff --git a/src/dict.c b/src/dict.c
--- a/src/dict.c
+++ b/src/dict.c
@@ -345,12 +345,28 @@ dict_copy(dict_T *orig, int deep, int co
 }
 
 /*
+ * Check for adding a function to g: or s:.
+ * If the name is wrong give an error message and return TRUE.
+ */
+    int
+dict_wrong_func_name(dict_T *d, typval_T *tv, char_u *name)
+{
+    return (d == get_globvar_dict()
+	    || (SCRIPT_ID_VALID(current_sctx.sc_sid)
+		  && d == &SCRIPT_ITEM(current_sctx.sc_sid)->sn_vars->sv_dict))
+	    && (tv->v_type == VAR_FUNC || tv->v_type == VAR_PARTIAL)
+	    && var_wrong_func_name(name, TRUE);
+}
+
+/*
  * Add item "item" to Dictionary "d".
  * Returns FAIL when out of memory and when key already exists.
  */
     int
 dict_add(dict_T *d, dictitem_T *item)
 {
+    if (dict_wrong_func_name(d, &item->di_tv, item->di_key))
+	return FAIL;
     return hash_add(&d->dv_hashtab, item->di_key);
 }
 
@@ -1109,6 +1125,8 @@ dict_extend(dict_T *d1, dict_T *d2, char
 		if (value_check_lock(di1->di_tv.v_lock, arg_errmsg, TRUE)
 			|| var_check_ro(di1->di_flags, arg_errmsg, TRUE))
 		    break;
+		if (dict_wrong_func_name(d1, &HI2DI(hi2)->di_tv, hi2->hi_key))
+		    break;
 		clear_tv(&di1->di_tv);
 		copy_tv(&HI2DI(hi2)->di_tv, &di1->di_tv);
 	    }
diff --git a/src/eval.c b/src/eval.c
--- a/src/eval.c
+++ b/src/eval.c
@@ -1462,12 +1462,8 @@ set_var_lval(
 		semsg(_(e_dictkey), lp->ll_newkey);
 		return;
 	    }
-	    if ((lp->ll_tv->vval.v_dict == get_globvar_dict()
-		    || lp->ll_tv->vval.v_dict ==
-			   &SCRIPT_ITEM(current_sctx.sc_sid)->sn_vars->sv_dict)
-		    && (rettv->v_type == VAR_FUNC
-			|| rettv->v_type == VAR_PARTIAL)
-		    && var_wrong_func_name(lp->ll_newkey, TRUE))
+	    if (dict_wrong_func_name(lp->ll_tv->vval.v_dict, rettv,
+								lp->ll_newkey))
 		return;
 
 	    // Need to add an item to the Dictionary.
diff --git a/src/proto/dict.pro b/src/proto/dict.pro
--- a/src/proto/dict.pro
+++ b/src/proto/dict.pro
@@ -13,6 +13,7 @@ dictitem_T *dictitem_alloc(char_u *key);
 void dictitem_remove(dict_T *dict, dictitem_T *item);
 void dictitem_free(dictitem_T *item);
 dict_T *dict_copy(dict_T *orig, int deep, int copyID);
+int dict_wrong_func_name(dict_T *d, typval_T *tv, char_u *name);
 int dict_add(dict_T *d, dictitem_T *item);
 int dict_add_number(dict_T *d, char *key, varnumber_T nr);
 int dict_add_bool(dict_T *d, char *key, varnumber_T nr);
diff --git a/src/testdir/test_functions.vim b/src/testdir/test_functions.vim
--- a/src/testdir/test_functions.vim
+++ b/src/testdir/test_functions.vim
@@ -2686,6 +2686,11 @@ func Test_builtin_check()
   call assert_fails('let g:.trim = {x -> " " .. x}', 'E704:')
   call assert_fails('let s:["trim"] = {x -> " " .. x}', 'E704:')
   call assert_fails('let s:.trim = {x -> " " .. x}', 'E704:')
+
+  call assert_fails('call extend(g:, #{foo: { -> "foo" }})', 'E704:')
+  let g:bar = 123
+  call extend(g:, #{bar: { -> "foo" }}, "keep")
+  call assert_fails('call extend(g:, #{bar: { -> "foo" }}, "force")', 'E704:')
 endfunc
 
 
diff --git a/src/version.c b/src/version.c
--- a/src/version.c
+++ b/src/version.c
@@ -751,6 +751,8 @@ static char *(features[]) =
 static int included_patches[] =
 {   /* Add new patch number below this line */
 /**/
+    2920,
+/**/
     2919,
 /**/
     2918,