patch 8.2.2739: Vim9: a lambda accepts too many arguments at the script level Commit: https://github.com/vim/vim/commit/767034c5b82ba8999d9fed2f997436e6e3e99419 Author: Bram Moolenaar <Bram@vim.org> Date: Fri Apr 9 17:24:52 2021 +0200 patch 8.2.2739: Vim9: a lambda accepts too many arguments at the script level Problem: Vim9: a lambda accepts too many arguments at the script level. Solution: Do not set uf_varargs in Vim9 script.

--- a/src/userfunc.c
+++ b/src/userfunc.c
@@ -1263,8 +1263,9 @@ get_lambda_tv(
 #endif
 	if (sandbox)
 	    flags |= FC_SANDBOX;
-	// can be called with more args than uf_args.ga_len
-	fp->uf_varargs = TRUE;
+	// In legacy script a lambda can be called with more args than
+	// uf_args.ga_len.
+	fp->uf_varargs = !in_vim9script();
 	fp->uf_flags = flags;
 	fp->uf_calls = 0;
 	fp->uf_script_ctx = current_sctx;