autocmd: add WinClosed event

- only fire once, just before freeing mem
- trigger when on a different buffer
- avoid recursive calls in another tab

2 files changed, 35 insertions, 4 deletions

diff --git a/src/nvim/auevents.lua b/src/nvim/auevents.lua
index a52789c795..d596edf551 100644
--- a/src/nvim/auevents.lua
+++ b/src/nvim/auevents.lua
@@ -110,6 +110,7 @@ return {
     'WinEnter',               -- after entering a window
     'WinLeave',               -- before leaving a window
     'WinNew',                 -- when entering a new window
+    'WinClosed',              -- after closing a window
   },
   aliases = {
     BufCreate = 'BufAdd',
@@ -129,5 +130,6 @@ return {
     TermOpen=true,
     UIEnter=true,
     UILeave=true,
+    WinClosed=true,
   },
 }
diff --git a/src/nvim/window.c b/src/nvim/window.c
index e913d33de0..4743dca3ff 100644
--- a/src/nvim/window.c
+++ b/src/nvim/window.c
@@ -2502,9 +2502,10 @@ int win_close(win_T *win, bool free_buf)
         return FAIL;
     }
     win->w_closing = true;
-    apply_autocmds(EVENT_WINLEAVE, NULL, NULL, FALSE, curbuf);
-    if (!win_valid(win))
+    apply_autocmds(EVENT_WINLEAVE, NULL, NULL, false, curbuf);
+    if (!win_valid(win)) {
       return FAIL;
+    }
     win->w_closing = false;
     if (last_window())
       return FAIL;
@@ -2534,6 +2535,12 @@ int win_close(win_T *win, bool free_buf)
     }
   }
 
+  // Fire WinClosed just before starting to free window-related resources.
+  do_autocmd_winclosed(win);
+  // autocmd may have freed the window already.
+  if (!win_valid_any_tab(win)) {
+    return OK;
+  }
 
   /* Free independent synblock before the buffer is freed. */
   if (win->w_buffer != NULL)
@@ -2576,6 +2583,7 @@ int win_close(win_T *win, bool free_buf)
     win_close_othertab(win, false, prev_curtab);
     return FAIL;
   }
+
   // Autocommands may have closed the window already, or closed the only
   // other window or moved to another tab page.
   if (!win_valid(win) || (!win->w_floating && last_window())
@@ -2585,8 +2593,9 @@ int win_close(win_T *win, bool free_buf)
 
   // let terminal buffers know that this window dimensions may be ignored
   win->w_closing = true;
-  /* Free the memory used for the window and get the window that received
-   * the screen space. */
+
+  // Free the memory used for the window and get the window that received
+  // the screen space.
   wp = win_free_mem(win, &dir, NULL);
 
   if (help_window) {
@@ -2678,6 +2687,19 @@ int win_close(win_T *win, bool free_buf)
   return OK;
 }
 
+static void do_autocmd_winclosed(win_T *win)
+  FUNC_ATTR_NONNULL_ALL
+{
+  static bool recursive = false;
+  if (recursive || !has_event(EVENT_WINCLOSED)) {
+    return;
+  }
+  recursive = true;
+  apply_autocmds(EVENT_WINCLOSED, win->w_buffer->b_fname,
+                 win->w_buffer->b_fname, false, win->w_buffer);
+  recursive = false;
+}
+
 /*
  * Close window "win" in tab page "tp", which is not the current tab page.
  * This may be the last window in that tab page and result in closing the tab,
@@ -2698,6 +2720,13 @@ void win_close_othertab(win_T *win, int free_buf, tabpage_T *tp)
     return;  // window is already being closed
   }
 
+  // Fire WinClosed just before starting to free window-related resources.
+  do_autocmd_winclosed(win);
+  // autocmd may have freed the window already.
+  if (!win_valid_any_tab(win)) {
+    return;
+  }
+
   if (win->w_buffer != NULL) {
     // Close the link to the buffer.
     close_buffer(win, win->w_buffer, free_buf ? DOBUF_UNLOAD : 0, false);