vim-patch:9.1.1253: abort when closing window with attached quickfix data

Problem:  If win_close() is called with a window that has quickfix stack
          attached to it, the corresponding quickfix buffer will be
          closed and freed after the buffer was already closed. At that
          time curwin->w_buffer points to NULL, which the CHECK_CURBUF
          will catch and abort if ABORT_ON_ERROR is defined
Solution: in wipe_qf_buffer() temporarily point curwin->w_buffer back to
          curbuf, the window will be closed anyhow, so it shouldn't
          matter that curbuf->b_nwindows isn't incremented.

closes: vim/vim#16993
closes: vim/vim#16985

ce80c59bfd

Co-authored-by: Christian Brabandt <cb@256bit.org>
Co-authored-by: Hirohito Higashi <h.east.727@gmail.com>

test/old/testdir/test_quickfix.vim

@@ -6596,4 +6596,12 @@ func Test_hardlink_fname()
   call Xtest_hardlink_fname('l')
 endfunc
 
+func Test_quickfix_close_buffer_crash()
+  new
+  lexpr 'test' | lopen
+  wincmd k
+  lclose
+  wincmd q
+endfunc
+
 " vim: shiftwidth=2 sts=2 expandtab