Revert "vim-patch:8.1.0877: new buffer used every time the quickfix window is opened"

This reverts commit e82b8ddef1.

Fix https://github.com/neovim/neovim/issues/13104

src/nvim/buffer.c

@@ -5397,12 +5397,16 @@ bool buf_hide(const buf_T *const buf)
 char_u *buf_spname(buf_T *buf)
 {
   if (bt_quickfix(buf)) {
-    // Differentiate between the quickfix and location list buffers using
+    win_T *win;
-    // the buffer number stored in the global quickfix stack.
+    tabpage_T *tp;
-    if (buf->b_fnum == qf_stack_get_bufnr()) {
+
+    // For location list window, w_llist_ref points to the location list.
+    // For quickfix window, w_llist_ref is NULL.
+    if (find_win_for_buf(buf, &win, &tp) && win->w_llist_ref != NULL) {
+      return (char_u *)_(msg_loclist);
+    } else {
       return (char_u *)_(msg_qflist);
     }
-    return (char_u *)_(msg_loclist);
   }
   // There is no _file_ when 'buftype' is "nofile", b_sfname
   // contains the name as specified by the user.

src/nvim/quickfix.c

@@ -73,7 +73,6 @@ struct qfline_S {
 // There is a stack of error lists.
 #define LISTCOUNT   10
 #define INVALID_QFIDX (-1)
-#define INVALID_QFBUFNR (0)
 
 /// Quickfix list type.
 typedef enum
@@ -124,7 +123,6 @@ struct qf_info_S {
   int qf_curlist;                   // current error list
   qf_list_T qf_lists[LISTCOUNT];
   qfltype_T qfl_type;  // type of list
-  int qf_bufnr;                     // quickfix window buffer number
 };
 
 static qf_info_T ql_info;         // global quickfix list
@@ -1698,28 +1696,6 @@ static void locstack_queue_delreq(qf_info_T *qi)
   qf_delq_head = q;
 }
 
-// Return the global quickfix stack window buffer number.
-int qf_stack_get_bufnr(void)
-{
-  return ql_info.qf_bufnr;
-}
-
-// Wipe the quickfix window buffer (if present) for the specified
-// quickfix/location list.
-static void wipe_qf_buffer(qf_info_T *qi)
-  FUNC_ATTR_NONNULL_ALL
-{
-  if (qi->qf_bufnr != INVALID_QFBUFNR) {
-    buf_T *const qfbuf = buflist_findnr(qi->qf_bufnr);
-    if (qfbuf != NULL && qfbuf->b_nwindows == 0) {
-      // If the quickfix buffer is not loaded in any window, then
-      // wipe the buffer.
-      close_buffer(NULL, qfbuf, DOBUF_WIPE, false);
-      qi->qf_bufnr = INVALID_QFBUFNR;
-    }
-  }
-}
-
 /// Free a location list stack
 static void ll_free_all(qf_info_T **pqi)
 {
@@ -1739,9 +1715,6 @@ static void ll_free_all(qf_info_T **pqi)
     if (quickfix_busy > 0) {
       locstack_queue_delreq(qi);
     } else {
-      // If the quickfix window buffer is loaded, then wipe it
-      wipe_qf_buffer(qi);
-
       for (i = 0; i < qi->qf_listcount; i++) {
         qf_free(qf_get_list(qi, i));
       }
@@ -1901,7 +1874,6 @@ static qf_info_T *qf_alloc_stack(qfltype_T qfltype)
   qf_info_T *qi = xcalloc(1, sizeof(qf_info_T));
   qi->qf_refcount++;
   qi->qfl_type = qfltype;
-  qi->qf_bufnr = INVALID_QFBUFNR;
 
   return qi;
 }
@@ -2538,8 +2510,7 @@ static int jump_to_help_window(qf_info_T *qi, bool newwin, int *opened_window)
   return OK;
 }
 
-// Find a non-quickfix window in the current tabpage using the given location
+// Find a non-quickfix window using the given location list.
-// list stack.
 // Returns NULL if a matching window is not found.
 static win_T *qf_find_win_with_loclist(const qf_info_T *ll)
   FUNC_ATTR_PURE FUNC_ATTR_WARN_UNUSED_RESULT
@@ -3589,7 +3560,7 @@ static void qf_set_cwindow_options(void)
   // switch off 'swapfile'
   set_option_value("swf", 0L, NULL, OPT_LOCAL);
   set_option_value("bt", 0L, "quickfix", OPT_LOCAL);
-  set_option_value("bh", 0L, "hide", OPT_LOCAL);
+  set_option_value("bh", 0L, "wipe", OPT_LOCAL);
   RESET_BINDING(curwin);
   curwin->w_p_diff = false;
   set_option_value("fdm", 0L, "manual", OPT_LOCAL);
@@ -3642,9 +3613,6 @@ static int qf_open_new_cwindow(qf_info_T *qi, int height)
   } else {
     // Create a new quickfix buffer
     (void)do_ecmd(0, NULL, NULL, NULL, ECMD_ONE, ECMD_HIDE, oldwin);
-
-    // save the number of the new buffer
-    qi->qf_bufnr = curbuf->b_fnum;
   }
 
   // Set the options for the quickfix buffer/window (if not already done)
@@ -3843,15 +3811,6 @@ static win_T *qf_find_win(const qf_info_T *qi)
 static buf_T *qf_find_buf(qf_info_T *qi)
   FUNC_ATTR_NONNULL_ALL FUNC_ATTR_WARN_UNUSED_RESULT
 {
-  if (qi->qf_bufnr != INVALID_QFBUFNR) {
-    buf_T *const qfbuf = buflist_findnr(qi->qf_bufnr);
-    if (qfbuf != NULL) {
-      return qfbuf;
-    }
-    // buffer is no longer present
-    qi->qf_bufnr = INVALID_QFBUFNR;
-  }
-
   FOR_ALL_TAB_WINDOWS(tp, win) {
     if (is_qf_win(win, qi)) {
       return win->w_buffer;
@@ -6296,6 +6255,20 @@ static int qf_set_properties(qf_info_T *qi, const dict_T *what, int action,
   return retval;
 }
 
+/// Find the non-location list window with the specified location list stack in
+/// the current tabpage.
+static win_T *find_win_with_ll(const qf_info_T *qi)
+  FUNC_ATTR_NONNULL_ALL FUNC_ATTR_WARN_UNUSED_RESULT
+{
+  FOR_ALL_WINDOWS_IN_TAB(wp, curtab) {
+    if ((wp->w_llist == qi) && !bt_quickfix(wp->w_buffer)) {
+      return wp;
+    }
+  }
+
+  return NULL;
+}
+
 // Free the entire quickfix/location list stack.
 // If the quickfix/location list window is open, then clear it.
 static void qf_free_stack(win_T *wp, qf_info_T *qi)
@@ -6310,10 +6283,12 @@ static void qf_free_stack(win_T *wp, qf_info_T *qi)
     qf_update_buffer(qi, NULL);
   }
 
+  win_T *llwin = NULL;
+  win_T *orig_wp = wp;
   if (wp != NULL && IS_LL_WINDOW(wp)) {
     // If in the location list window, then use the non-location list
     // window with this location list (if present)
-    win_T *const llwin = qf_find_win_with_loclist(qi);
+    llwin = find_win_with_ll(qi);
     if (llwin != NULL) {
       wp = llwin;
     }
@@ -6324,17 +6299,16 @@ static void qf_free_stack(win_T *wp, qf_info_T *qi)
     // quickfix list
     qi->qf_curlist = 0;
     qi->qf_listcount = 0;
-  } else if (qfwin != NULL) {
+  } else if (IS_LL_WINDOW(orig_wp)) {
     // If the location list window is open, then create a new empty location
     // list
     qf_info_T *new_ll = qf_alloc_stack(QFLT_LOCATION);
-    new_ll->qf_bufnr = qfwin->w_buffer->b_fnum;
 
     // first free the list reference in the location list window
-    ll_free_all(&qfwin->w_llist_ref);
+    ll_free_all(&orig_wp->w_llist_ref);
 
-    qfwin->w_llist_ref = new_ll;
+    orig_wp->w_llist_ref = new_ll;
-    if (wp != qfwin) {
+    if (llwin != NULL) {
       win_set_loclist(wp, new_ll);
     }
   }

src/nvim/testdir/test_quickfix.vim

@@ -4151,6 +4151,7 @@ func Xqfbuf_test(cchar)
 endfunc
 
 func Test_qfbuf()
+  throw 'skipped: enable after porting patch 8.1.0877'
   call Xqfbuf_test('c')
   call Xqfbuf_test('l')
 endfunc