vim-patch:8.1.0489: crash when autocmd clears vimpgrep location list

Problem:    Crash when autocmd clears vimpgrep location list.
Solution:   Return from qf_jump_edit_buffer() early. (Yegappan Lakshmanan)
https://github.com/vim/vim/commit/b6f1480a6a8b1a6fa4d5da97aeb5f4755b71eb91

2 files changed, 65 insertions, 21 deletions

diff --git a/src/nvim/quickfix.c b/src/nvim/quickfix.c
index f6798ff692..a416bfde14 100644
--- a/src/nvim/quickfix.c
+++ b/src/nvim/quickfix.c
@@ -2702,43 +2702,45 @@ static int qf_jump_edit_buffer(qf_info_T *qi, qfline_T *qf_ptr, int forceit,
   qf_list_T *qfl = qf_get_curlist(qi);
   qfltype_T qfl_type = qfl->qfl_type;
   int retval = OK;
+  int old_qf_curlist = qi->qf_curlist;
+  unsigned save_qfid = qfl->qf_id;
 
   if (qf_ptr->qf_type == 1) {
     // Open help file (do_ecmd() will set b_help flag, readfile() will
     // set b_p_ro flag).
     if (!can_abandon(curbuf, forceit)) {
       no_write_message();
-      retval = FAIL;
+      return FAIL;
     } else {
       retval = do_ecmd(qf_ptr->qf_fnum, NULL, NULL, NULL, (linenr_T)1,
                        ECMD_HIDE + ECMD_SET_HELP,
                        oldwin == curwin ? curwin : NULL);
     }
   } else {
-    unsigned save_qfid = qfl->qf_id;
-
     retval = buflist_getfile(qf_ptr->qf_fnum, (linenr_T)1,
                              GETF_SETMARK | GETF_SWITCH, forceit);
+  }
+  // If a location list, check whether the associated window is still
+  // present.
+  if (qfl_type == QFLT_LOCATION && !win_valid_any_tab(oldwin)) {
+    EMSG(_("E924: Current window was closed"));
+    *opened_window = false;
+    return NOTDONE;
+  }
 
-    if (qfl_type == QFLT_LOCATION) {
-      // Location list. Check whether the associated window is still
-      // present and the list is still valid.
-      if (!win_valid_any_tab(oldwin)) {
-        EMSG(_("E924: Current window was closed"));
-        *opened_window = false;
-        return NOTDONE;
-      } else if (!qflist_valid(oldwin, save_qfid)) {
-        EMSG(_(e_loc_list_changed));
-        return NOTDONE;
-      }
-    } else if (!is_qf_entry_present(qfl, qf_ptr)) {
-      if (qfl_type == QFLT_QUICKFIX) {
-        EMSG(_("E925: Current quickfix was changed"));
-      } else {
-        EMSG(_(e_loc_list_changed));
-      }
-      return NOTDONE;
+  if (qfl_type == QFLT_QUICKFIX && !qflist_valid(NULL, save_qfid)) {
+    EMSG(_("E925: Current quickfix was changed"));
+    return NOTDONE;
+  }
+
+  if (old_qf_curlist != qi->qf_curlist
+      || !is_qf_entry_present(qfl, qf_ptr)) {
+    if (qfl_type == QFLT_QUICKFIX) {
+      EMSG(_("E925: Current quickfix was changed"));
+    } else {
+      EMSG(_(e_loc_list_changed));
     }
+    return NOTDONE;
   }
 
   return retval;
diff --git a/src/nvim/testdir/test_quickfix.vim b/src/nvim/testdir/test_quickfix.vim
index 926103b69f..52226327b1 100644
--- a/src/nvim/testdir/test_quickfix.vim
+++ b/src/nvim/testdir/test_quickfix.vim
@@ -3342,6 +3342,17 @@ func Test_lvimgrep_crash()
   augroup QF_Test
     au!
   augroup END
+
+  new | only
+  augroup QF_Test
+    au!
+    au BufEnter * call setloclist(0, [], 'r')
+  augroup END
+  call assert_fails('lvimgrep Test_lvimgrep_crash *', 'E926:')
+  augroup QF_Test
+    au!
+  augroup END
+
   enew | only
 endfunc
 
@@ -3432,6 +3443,37 @@ func Test_lhelpgrep_autocmd()
   call assert_equal('help', &filetype)
   call assert_equal(1, getloclist(0, {'nr' : '$'}).nr)
   au! QuickFixCmdPost
+
+  new | only
+  augroup QF_Test
+    au!
+    au BufEnter * call setqflist([], 'f')
+  augroup END
+  call assert_fails('helpgrep quickfix', 'E925:')
+  augroup QF_Test
+    au! BufEnter
+  augroup END
+
+  new | only
+  augroup QF_Test
+    au!
+    au BufEnter * call setqflist([], 'r')
+  augroup END
+  call assert_fails('helpgrep quickfix', 'E925:')
+  augroup QF_Test
+    au! BufEnter
+  augroup END
+
+  new | only
+  augroup QF_Test
+    au!
+    au BufEnter * call setloclist(0, [], 'r')
+  augroup END
+  call assert_fails('lhelpgrep quickfix', 'E926:')
+  augroup QF_Test
+    au! BufEnter
+  augroup END
+
   new | only
 endfunc