patch 8.1.0060: crash when autocommands delete the current buffer

Problem:    Crash when autocommands delete the current buffer. (Dominique
            Pelle)
Solution:   Check that autocommands don't change the buffer.
diff --git a/src/testdir/test_quickfix.vim b/src/testdir/test_quickfix.vim
index c3850ce..eade52f 100644
--- a/src/testdir/test_quickfix.vim
+++ b/src/testdir/test_quickfix.vim
@@ -3350,3 +3350,15 @@
   call assert_equal('Errors', w:quickfix_title)
   cclose
 endfunc
+
+func Test_lbuffer_with_bwipe()
+  new
+  new
+  augroup nasty
+    au * * bwipe
+  augroup END
+  lbuffer
+  augroup nasty
+    au!
+  augroup END
+endfunc