commit da479c7597a61c4d50c842df21c9294bd9bf1037
author Bram Moolenaar <Bram@vim.org> Sat Apr 10 21:01:38 2021 +0200
committer Bram Moolenaar <Bram@vim.org> Sat Apr 10 21:01:38 2021 +0200
tree 44a5cbf9c031551b9fcd79f69c727d2d7566f912
parent fe95b94ffa75c4925ad16c43f94092f2b1d35fc6

patch 8.2.2750: Vim9: error for using underscore in nested function

Problem:    Vim9: error for using underscore in nested function.
Solution:   Do not consider "_" already defined. (closes #8096)

src/testdir/test_vim9_func.vim

diff --git a/src/testdir/test_vim9_func.vim b/src/testdir/test_vim9_func.vim
index 6b353dd..a97146d 100644
--- a/src/testdir/test_vim9_func.vim
+++ b/src/testdir/test_vim9_func.vim
@@ -2637,6 +2637,8 @@
         return _
       endfunc
       assert_equal('too', Oktoo())
+
+      assert_equal([[1], [2], [3]], range(3)->mapnew((_, v) => [v]->map((_, w) => w + 1)))
   END
   CheckScriptSuccess(lines)
 

src/version.c

diff --git a/src/version.c b/src/version.c
index 7785ac3..ed22375 100644
--- a/src/version.c
+++ b/src/version.c
@@ -751,6 +751,8 @@
 static int included_patches[] =
 {   /* Add new patch number below this line */
 /**/
+    2750,
+/**/
     2749,
 /**/
     2748,

src/vim9compile.c

diff --git a/src/vim9compile.c b/src/vim9compile.c
index b005ff2..02c75c4 100644
--- a/src/vim9compile.c
+++ b/src/vim9compile.c
@@ -422,6 +422,10 @@
     int		c = p[len];
     ufunc_T	*ufunc = NULL;
 
+    // underscore argument is OK
+    if (len == 1 && *p == '_')
+	return OK;
+
     if (script_var_exists(p, len, cctx) == OK)
     {
 	if (is_arg)