1 files changed, 41 insertions, 15 deletions

diff --git a/src/nvim/window.c b/src/nvim/window.c
index 03a2e9a842..9c6a2e26a6 100644
--- a/src/nvim/window.c
+++ b/src/nvim/window.c
@@ -1065,6 +1065,23 @@ bool win_valid(win_T *win) FUNC_ATTR_PURE FUNC_ATTR_WARN_UNUSED_RESULT
   return false;
 }
 
+/// Check if "win" is a pointer to an existing window in any tabpage.
+///
+/// @param  win  window to check
+bool win_valid_any_tab(win_T *win) FUNC_ATTR_PURE FUNC_ATTR_WARN_UNUSED_RESULT
+{
+  if (win == NULL) {
+    return false;
+  }
+
+  FOR_ALL_TAB_WINDOWS(tp, wp) {
+    if (wp == win) {
+      return true;
+    }
+  }
+  return false;
+}
+
 /*
  * Return the number of windows.
  */
@@ -1918,7 +1935,7 @@ int win_close(win_T *win, int free_buf)
   if (win->w_buffer != NULL) {
     win->w_closing = true;
     close_buffer(win, win->w_buffer, free_buf ? DOBUF_UNLOAD : 0, true);
-    if (win_valid(win)) {
+    if (win_valid_any_tab(win)) {
       win->w_closing = false;
     }
 
@@ -1938,11 +1955,19 @@ int win_close(win_T *win, int free_buf)
       curwin->w_buffer = curbuf;
     getout(0);
   }
-  /* Autocommands may have closed the window already, or closed the only
-   * other window or moved to another tab page. */
-  else if (!win_valid(win) || last_window() || curtab != prev_curtab
-           || close_last_window_tabpage(win, free_buf, prev_curtab))
+  // Autocommands may have moved to another tab page.
+  if (curtab != prev_curtab && win_valid_any_tab(win)
+      && win->w_buffer == NULL) {
+    // Need to close the window anyway, since the buffer is NULL.
+    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) || last_window()
+      || close_last_window_tabpage(win, free_buf, prev_curtab)) {
+    return FAIL;
+  }
 
   // let terminal buffers know that this window dimensions may be ignored
   win->w_closing = true;
@@ -2019,12 +2044,16 @@ void win_close_othertab(win_T *win, int free_buf, tabpage_T *tp)
   tabpage_T   *ptp = NULL;
   int free_tp = FALSE;
 
-  assert(win->w_buffer);  // to avoid np dereference warning in next line
-  if (win->w_closing || win->w_buffer->b_closing)
-    return;     /* window is already being closed */
+  // Get here with win->w_buffer == NULL when win_close() detects the tab page
+  // changed.
+  if (win->w_closing || (win->w_buffer != NULL && win->w_buffer->b_closing)) {
+    return;  // window is already being closed
+  }
 
-  /* Close the link to the buffer. */
-  close_buffer(win, win->w_buffer, free_buf ? DOBUF_UNLOAD : 0, FALSE);
+  if (win->w_buffer != NULL) {
+    // Close the link to the buffer.
+    close_buffer(win, win->w_buffer, free_buf ? DOBUF_UNLOAD : 0, false);
+  }
 
   /* Careful: Autocommands may have closed the tab page or made it the
    * current tab page.  */
@@ -3213,11 +3242,8 @@ void goto_tabpage(int n)
   int i;
 
   if (text_locked()) {
-    /* Not allowed when editing the command line. */
-    if (cmdwin_type != 0)
-      EMSG(_(e_cmdwin));
-    else
-      EMSG(_(e_secure));
+    // Not allowed when editing the command line.
+    text_locked_msg();
     return;
   }