patch 8.2.3162: Vim9: argument types are not checked at compile time Commit: https://github.com/vim/vim/commit/1a71d31bf34b0b2b08517903826004ec6fd440e5 Author: Yegappan Lakshmanan <yegappan@yahoo.com> Date: Thu Jul 15 12:49:58 2021 +0200 patch 8.2.3162: Vim9: argument types are not checked at compile time Problem: Vim9: argument types are not checked at compile time. Solution: Add more type checks. (Yegappan Lakshmanan, closes https://github.com/vim/vim/issues/8560)

--- a/src/evalwindow.c
+++ b/src/evalwindow.c
@@ -653,6 +653,12 @@ f_tabpagewinnr(typval_T *argvars UNUSED,
     int		nr = 1;
     tabpage_T	*tp;
 
+    if (in_vim9script()
+	    && (check_for_number_arg(argvars, 0) == FAIL
+		|| (argvars[1].v_type != VAR_UNKNOWN
+		    && check_for_string_arg(argvars, 1) == FAIL)))
+	return;
+
     tp = find_tabpage((int)tv_get_number(&argvars[0]));
     if (tp == NULL)
 	nr = 0;