Fix wrong handling of minibuffers when frames get iconified/made invisible

This should fix bug #47766.

* lisp/window.el (window-deletable-p): Add a quote where it was missing from
minibuffer-follows-selected-frame.

* src/frame.c (check_minibuf_window): Delete the function.
(delete_frame): In place of calling check_minibuf_window, call
move_minibuffers_onto_frame, possibly to move minibuffers onto the new current
frame.
(Fmake_frame_invisible, Ficonify_frame): Remove calls to check_minibuf_window.

* src/minibuf.c (Factive_minibuffer_window): Search the frames for the active
minibuffer rather than just assuming minibuf_window has been correctly
updated.

lisp/window.el

@@ -4117,7 +4117,7 @@ frame can be safely deleted."
 		  (let ((minibuf (active-minibuffer-window)))
 		    (and minibuf (eq frame (window-frame minibuf))
                          (not (eq (default-toplevel-value
-                                    minibuffer-follows-selected-frame)
+                                    'minibuffer-follows-selected-frame)
                                   t)))))
 	'frame))
      ((window-minibuffer-p window)

src/frame.c

@@ -1929,52 +1929,6 @@ other_frames (struct frame *f, bool invisible, bool force)
   return false;
 }
 
-/* Make sure that minibuf_window doesn't refer to FRAME's minibuffer
-   window.  Preferably use the selected frame's minibuffer window
-   instead.  If the selected frame doesn't have one, get some other
-   frame's minibuffer window.  SELECT non-zero means select the new
-   minibuffer window.  */
-static void
-check_minibuf_window (Lisp_Object frame, int select)
-{
-  struct frame *f = decode_live_frame (frame);
-
-  XSETFRAME (frame, f);
-
-  if (WINDOWP (minibuf_window) && EQ (f->minibuffer_window, minibuf_window))
-    {
-      Lisp_Object frames, this, window = make_fixnum (0);
-
-      if (!EQ (frame, selected_frame)
-	  && FRAME_HAS_MINIBUF_P (XFRAME (selected_frame)))
-	window = FRAME_MINIBUF_WINDOW (XFRAME (selected_frame));
-      else
-	FOR_EACH_FRAME (frames, this)
-	  {
-	    if (!EQ (this, frame) && FRAME_HAS_MINIBUF_P (XFRAME (this)))
-	      {
-		window = FRAME_MINIBUF_WINDOW (XFRAME (this));
-		break;
-	      }
-	  }
-
-      /* Don't abort if no window was found (Bug#15247).  */
-      if (WINDOWP (window))
-	{
-	  /* Use set_window_buffer instead of Fset_window_buffer (see
-	     discussion of bug#11984, bug#12025, bug#12026).  */
-	  set_window_buffer (window, XWINDOW (minibuf_window)->contents, 0, 0);
-	  minibuf_window = window;
-
-	  /* SELECT non-zero usually means that FRAME's minibuffer
-	     window was selected; select the new one.  */
-	  if (select)
-	    Fselect_window (minibuf_window, Qnil);
-	}
-    }
-}
-
-
 /**
  * delete_frame:
  *
@@ -1989,7 +1943,7 @@ delete_frame (Lisp_Object frame, Lisp_Object force)
   struct frame *sf;
   struct kboard *kb;
   Lisp_Object frames, frame1;
-  int minibuffer_selected, is_tooltip_frame;
+  int is_tooltip_frame;
   bool nochild = !FRAME_PARENT_FRAME (f);
   Lisp_Object minibuffer_child_frame = Qnil;
 
@@ -2097,7 +2051,6 @@ delete_frame (Lisp_Object frame, Lisp_Object force)
 
   /* At this point, we are committed to deleting the frame.
      There is no more chance for errors to prevent it.  */
-  minibuffer_selected = EQ (minibuf_window, selected_window);
   sf = SELECTED_FRAME ();
   /* Don't let the frame remain selected.  */
   if (f == sf)
@@ -2155,9 +2108,10 @@ delete_frame (Lisp_Object frame, Lisp_Object force)
       do_switch_frame (frame1, 0, 1, Qnil);
       sf = SELECTED_FRAME ();
     }
-
-  /* Don't allow minibuf_window to remain on a deleted frame.  */
-  check_minibuf_window (frame, minibuffer_selected);
+  else
+    /* Ensure any minibuffers on FRAME are moved onto the selected
+       frame.  */
+    move_minibuffers_onto_frame (f, true);
 
   /* Don't let echo_area_window to remain on a deleted frame.  */
   if (EQ (f->minibuffer_window, echo_area_window))
@@ -2788,9 +2742,6 @@ displayed in the terminal.  */)
   if (NILP (force) && !other_frames (f, true, false))
     error ("Attempt to make invisible the sole visible or iconified frame");
 
-  /* Don't allow minibuf_window to remain on an invisible frame.  */
-  check_minibuf_window (frame, EQ (minibuf_window, selected_window));
-
   if (FRAME_WINDOW_P (f) && FRAME_TERMINAL (f)->frame_visible_invisible_hook)
     FRAME_TERMINAL (f)->frame_visible_invisible_hook (f, false);
 
@@ -2833,9 +2784,6 @@ for how to proceed.  */)
     }
 #endif	/* HAVE_WINDOW_SYSTEM */
 
-  /* Don't allow minibuf_window to remain on an iconified frame.  */
-  check_minibuf_window (frame, EQ (minibuf_window, selected_window));
-
   if (FRAME_WINDOW_P (f) && FRAME_TERMINAL (f)->iconify_frame_hook)
     FRAME_TERMINAL (f)->iconify_frame_hook (f);
 

src/minibuf.c

@@ -212,7 +212,23 @@ DEFUN ("active-minibuffer-window", Factive_minibuffer_window,
        doc: /* Return the currently active minibuffer window, or nil if none.  */)
      (void)
 {
-  return minibuf_level ? minibuf_window : Qnil;
+  Lisp_Object frames, frame;
+  struct frame *f;
+  Lisp_Object innermost_MB;
+
+  if (!minibuf_level)
+    return Qnil;
+
+  innermost_MB = nth_minibuffer (minibuf_level);
+  FOR_EACH_FRAME (frames, frame)
+    {
+      f = XFRAME (frame);
+      if (FRAME_LIVE_P (f)
+	  && WINDOW_LIVE_P (f->minibuffer_window)
+	  && EQ (XWINDOW (f->minibuffer_window)->contents, innermost_MB))
+	return f->minibuffer_window;
+    }
+  return minibuf_window;	/* "Can't happen." */
 }
 
 DEFUN ("set-minibuffer-window", Fset_minibuffer_window,