# HG changeset patch
# User Bram Moolenaar <Bram@vim.org>
# Date 1625250605 -7200
# Node ID cd5e8df05a6465fbcbd4498856b75b5ed7dba2b8
# Parent  143c87f12b9b917d0a708626144eb4667f1d7fe7
patch 8.2.3083: crash when passing null string to charclass()

Commit: https://github.com/vim/vim/commit/72463f883cdfd08e29ab0018ef3889284848d5f1
Author: Christian Brabandt <cb@256bit.org>
Date:   Fri Jul 2 20:19:31 2021 +0200

    patch 8.2.3083: crash when passing null string to charclass()

    Problem:    Crash when passing null string to charclass().
    Solution:   Bail out when string pointer is NULL. (Christian Brabandt,
                closes #8498, closes #8260)

diff --git a/src/mbyte.c b/src/mbyte.c
--- a/src/mbyte.c
+++ b/src/mbyte.c
@@ -5587,7 +5587,8 @@ f_setcellwidths(typval_T *argvars, typva
     void
 f_charclass(typval_T *argvars, typval_T *rettv UNUSED)
 {
-    if (check_for_string_arg(argvars, 0) == FAIL)
+    if (check_for_string_arg(argvars, 0) == FAIL
+	    || argvars[0].vval.v_string == NULL)
 	return;
     rettv->vval.v_number = mb_get_class(argvars[0].vval.v_string);
 }
diff --git a/src/testdir/test_functions.vim b/src/testdir/test_functions.vim
--- a/src/testdir/test_functions.vim
+++ b/src/testdir/test_functions.vim
@@ -2169,6 +2169,8 @@ func Test_charclass()
   call assert_equal(1, charclass('.'))
   call assert_equal(2, charclass('x'))
   call assert_equal(3, charclass("\u203c"))
+  " this used to crash vim
+  call assert_equal(0, "xxx"[-1]->charclass())
 endfunc
 
 func Test_eventhandler()
diff --git a/src/version.c b/src/version.c
--- a/src/version.c
+++ b/src/version.c
@@ -756,6 +756,8 @@ static char *(features[]) =
 static int included_patches[] =
 {   /* Add new patch number below this line */
 /**/
+    3083,
+/**/
     3082,
 /**/
     3081,