# HG changeset patch
# User Bram Moolenaar <Bram@vim.org>
# Date 1643135404 -3600
# Node ID a4746d1a3cf3e9deadc1545bc9742583e16632d7
# Parent  94507d9cc3705ed472f73345886a674c4432b3db
patch 8.2.4217: illegal memory access when undo makes Visual area invalid

Commit: https://github.com/vim/vim/commit/8d02ce1ed75d008c34a5c9aaa51b67cbb9d33baa
Author: Bram Moolenaar <Bram@vim.org>
Date:   Tue Jan 25 18:24:00 2022 +0000

    patch 8.2.4217: illegal memory access when undo makes Visual area invalid

    Problem:    Illegal memory access when undo makes Visual area invalid.
    Solution:   Correct the Visual area after undo.

diff --git a/src/testdir/test_visual.vim b/src/testdir/test_visual.vim
--- a/src/testdir/test_visual.vim
+++ b/src/testdir/test_visual.vim
@@ -1339,5 +1339,20 @@ func Test_visual_ex_copy_line()
   bwipe!
 endfunc
 
+" This was leaving the end of the Visual area beyond the end of a line.
+" Set 'undolevels' to start a new undo block.
+func Test_visual_undo_deletes_last_line()
+  new
+  call setline(1, ["aaa", "ccc", "dyd"])
+  set undolevels=100
+  exe "normal obbbbbbbbbxbb\<Esc>"
+  set undolevels=100
+  /y
+  exe "normal ggvjfxO"
+  undo
+  normal gNU
+  bwipe!
+endfunc
+
 
 " vim: shiftwidth=2 sts=2 expandtab
diff --git a/src/undo.c b/src/undo.c
--- a/src/undo.c
+++ b/src/undo.c
@@ -3029,6 +3029,8 @@ u_undo_end(
 	}
     }
 #endif
+    if (VIsual_active)
+	check_pos(curbuf, &VIsual);
 
     smsg_attr_keep(0, _("%ld %s; %s #%ld  %s"),
 	    u_oldcount < 0 ? -u_oldcount : u_oldcount,
diff --git a/src/version.c b/src/version.c
--- a/src/version.c
+++ b/src/version.c
@@ -751,6 +751,8 @@ static char *(features[]) =
 static int included_patches[] =
 {   /* Add new patch number below this line */
 /**/
+    4217,
+/**/
     4216,
 /**/
     4215,