# HG changeset patch
# User Bram Moolenaar <Bram@vim.org>
# Date 1653224402 -7200
# Node ID ba083decce5d3882a98c2bf0cf56bb07a869ba98
# Parent  0ed1893dc0bc5ab3b0338874be3d8c1cbfa3d29a
patch 8.2.4998: Vim9: crash when using multiple funcref()

Commit: https://github.com/vim/vim/commit/bce69d65dd41020ea1d727337a3baf9e95b40c35
Author: Bram Moolenaar <Bram@vim.org>
Date:   Sun May 22 13:45:52 2022 +0100

    patch 8.2.4998: Vim9: crash when using multiple funcref()

    Problem:    Vim9: crash when using multiple funcref().
    Solution:   Check if varargs type is NULL. (closes https://github.com/vim/vim/issues/10467)

diff --git a/src/testdir/test_vim9_func.vim b/src/testdir/test_vim9_func.vim
--- a/src/testdir/test_vim9_func.vim
+++ b/src/testdir/test_vim9_func.vim
@@ -4107,6 +4107,47 @@ func Test_lambda_allocation_failure()
   bw!
 endfunc
 
+def Test_multiple_funcref()
+  # This was using a NULL pointer
+  var lines =<< trim END
+      vim9script
+      def A(F: func, ...args: list<any>): func
+          return funcref(F, args)
+      enddef
+
+      def B(F: func): func
+          return funcref(A, [F])
+      enddef
+
+      def Test(n: number)
+      enddef
+
+      const X = B(Test)
+      X(1)
+  END
+  v9.CheckScriptSuccess(lines)
+
+  # slightly different case
+  lines =<< trim END
+      vim9script
+
+      def A(F: func, ...args: list<any>): any
+          return call(F, args)
+      enddef
+
+      def B(F: func): func
+          return funcref(A, [F])
+      enddef
+
+      def Test(n: number)
+      enddef
+
+      const X = B(Test)
+      X(1)
+  END
+  v9.CheckScriptSuccess(lines)
+enddef
+
 " The following messes up syntax highlight, keep near the end.
 if has('python3')
   def Test_python3_command()
diff --git a/src/version.c b/src/version.c
--- a/src/version.c
+++ b/src/version.c
@@ -735,6 +735,8 @@ static char *(features[]) =
 static int included_patches[] =
 {   /* Add new patch number below this line */
 /**/
+    4998,
+/**/
     4997,
 /**/
     4996,
diff --git a/src/vim9type.c b/src/vim9type.c
--- a/src/vim9type.c
+++ b/src/vim9type.c
@@ -807,7 +807,11 @@ check_argument_types(
 	else
 	    tv = &argvars[i];
 	if (varargs && i >= type->tt_argcount - 1)
-	    expected = type->tt_args[type->tt_argcount - 1]->tt_member;
+	{
+	    expected = type->tt_args[type->tt_argcount - 1];
+	    if (expected != NULL)
+		expected = expected->tt_member;
+	}
 	else
 	    expected = type->tt_args[i];
 	if (check_typval_arg_type(expected, tv, NULL, i + 1) == FAIL)