--- a/src/buffer.c
+++ b/src/buffer.c
@@ -1186,7 +1186,10 @@ do_buffer(action, start, dir, count, for
 		   && !(curwin->w_closing || curwin->w_buffer->b_closing)
 # endif
 		   && (firstwin != lastwin || first_tabpage->tp_next != NULL))
-	    win_close(curwin, FALSE);
+	{
+	    if (win_close(curwin, FALSE) == FAIL)
+		break;
+	}
 #endif
 
 	/*

--- a/src/proto/window.pro
+++ b/src/proto/window.pro
@@ -9,7 +9,7 @@ void win_move_after __ARGS((win_T *win1,
 void win_equal __ARGS((win_T *next_curwin, int current, int dir));
 void close_windows __ARGS((buf_T *buf, int keep_curwin));
 int one_window __ARGS((void));
-void win_close __ARGS((win_T *win, int free_buf));
+int win_close __ARGS((win_T *win, int free_buf));
 void win_close_othertab __ARGS((win_T *win, int free_buf, tabpage_T *tp));
 void win_free_all __ARGS((void));
 win_T *winframe_remove __ARGS((win_T *win, int *dirp, tabpage_T *tp));

--- a/src/version.c
+++ b/src/version.c
@@ -728,6 +728,8 @@ static char *(features[]) =
 static int included_patches[] =
 {   /* Add new patch number below this line */
 /**/
+    4,
+/**/
     3,
 /**/
     2,

--- a/src/window.c
+++ b/src/window.c
@@ -2172,8 +2172,9 @@ close_last_window_tabpage(win, free_buf,
  * If "free_buf" is TRUE related buffer may be unloaded.
  *
  * Called by :quit, :close, :xit, :wq and findtag().
+ * Returns FAIL when the window was not closed.
  */
-    void
+    int
 win_close(win, free_buf)
     win_T	*win;
     int		free_buf;
@@ -2190,21 +2191,21 @@ win_close(win, free_buf)
     if (last_window())
     {
 	EMSG(_("E444: Cannot close last window"));
-	return;
+	return FAIL;
     }
 
 #ifdef FEAT_AUTOCMD
     if (win->w_closing || (win->w_buffer != NULL && win->w_buffer->b_closing))
-	return; /* window is already being closed */
+	return FAIL; /* window is already being closed */
     if (win == aucmd_win)
     {
 	EMSG(_("E813: Cannot close autocmd window"));
-	return;
+	return FAIL;
     }
     if ((firstwin == aucmd_win || lastwin == aucmd_win) && one_window())
     {
 	EMSG(_("E814: Cannot close window, only autocmd window would remain"));
-	return;
+	return FAIL;
     }
 #endif
 
@@ -2212,7 +2213,7 @@ win_close(win, free_buf)
      * and then close the window and the tab page to avoid that curwin and
      * curtab are invalid while we are freeing memory. */
     if (close_last_window_tabpage(win, free_buf, prev_curtab))
-      return;
+      return FAIL;
 
     /* When closing the help window, try restoring a snapshot after closing
      * the window.  Otherwise clear the snapshot, it's now invalid. */
@@ -2240,22 +2241,22 @@ win_close(win, free_buf)
 	    win->w_closing = TRUE;
 	    apply_autocmds(EVENT_BUFLEAVE, NULL, NULL, FALSE, curbuf);
 	    if (!win_valid(win))
-		return;
+		return FAIL;
 	    win->w_closing = FALSE;
 	    if (last_window())
-		return;
+		return FAIL;
 	}
 	win->w_closing = TRUE;
 	apply_autocmds(EVENT_WINLEAVE, NULL, NULL, FALSE, curbuf);
 	if (!win_valid(win))
-	    return;
+	    return FAIL;
 	win->w_closing = FALSE;
 	if (last_window())
-	    return;
+	    return FAIL;
 # ifdef FEAT_EVAL
 	/* autocmds may abort script processing */
 	if (aborting())
-	    return;
+	    return FAIL;
 # endif
     }
 #endif
@@ -2303,7 +2304,7 @@ win_close(win, free_buf)
      * 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))
-	return;
+	return FAIL;
 
     /* Free the memory used for the window and get the window that received
      * the screen space. */
@@ -2383,6 +2384,7 @@ win_close(win, free_buf)
 #endif
 
     redraw_all_later(NOT_VALID);
+    return OK;
 }
 
 /*