patch 8.2.2918: builtin function can be shadowed by global variable

Problem:    Builtin function can be shadowed by global variable.
Solution:   Check for builtin function before variable. (Yasuhiro Matsumoto,
            closes #8302)

Author: brammool

src/eval.c

@@ -1462,6 +1462,13 @@ 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))
+		return;
 
 	    // Need to add an item to the Dictionary.
 	    di = dictitem_alloc(lp->ll_newkey);

src/testdir/test_functions.vim

@@ -2681,4 +2681,12 @@ func Test_gettext()
   call assert_fails('call gettext(1)', 'E475:')
 endfunc
 
+func Test_builtin_check()
+  call assert_fails('let g:["trim"] = {x -> " " .. x}', 'E704:')
+  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:')
+endfunc
+
+
 " vim: shiftwidth=2 sts=2 expandtab

src/version.c

@@ -750,6 +750,8 @@ static char *(features[]) =
 
 static int included_patches[] =
 {   /* Add new patch number below this line */
+/**/
+    2918,
 /**/
     2917,
 /**/