Check minibuffer windows are live windows, rather than assuming it

This partly fixes bug #47207.

* src/minibuf.c (choose_minibuf_frame, move_minibuffers_onto_frame)
(read_minibuf (twice), read_minibuf_unwind): Before using a frame's
->minibuffer_window field, check it is valid with WINDOW_LIVE_P.
(choose_minibuf_frame): Remove the emacs_abort for a null minibuffer.

1 files changed, 24 insertions, 14 deletions

diff --git a/src/minibuf.c b/src/minibuf.c
index c9831fd50f4..a3c1b99bf32 100644
--- a/src/minibuf.c
+++ b/src/minibuf.c
@@ -112,13 +112,15 @@ choose_minibuf_frame (void)
 {
   if (FRAMEP (selected_frame)
       && FRAME_LIVE_P (XFRAME (selected_frame))
+      && WINDOW_LIVE_P (XFRAME (selected_frame)->minibuffer_window)
       && !EQ (minibuf_window, XFRAME (selected_frame)->minibuffer_window))
     {
       struct frame *sf = XFRAME (selected_frame);
-      /* I don't think that any frames may validly have a null minibuffer
-         window anymore.  */
-      if (NILP (sf->minibuffer_window))
-        emacs_abort ();
+      /* I don't think that any frames may validly have a null
+         minibuffer window anymore.  (2021-04-15): Tooltip frames have
+         a null MB.  Comment out the following.  */
+      /* if (NILP (sf->minibuffer_window)) */
+      /*        emacs_abort (); */
 
       minibuf_window = sf->minibuffer_window;
     }
@@ -195,7 +197,9 @@ move_minibuffers_onto_frame (struct frame *of, bool for_deletion)
         && (for_deletion || minibuf_follows_frame () || FRAME_INITIAL_P (of))))
     return;
   if (FRAME_LIVE_P (f)
-      && !EQ (f->minibuffer_window, of->minibuffer_window))
+      && !EQ (f->minibuffer_window, of->minibuffer_window)
+      && WINDOW_LIVE_P (f->minibuffer_window) /* F not a tootip frame */
+      && WINDOW_LIVE_P (of->minibuffer_window))
     {
       zip_minibuffer_stacks (f->minibuffer_window, of->minibuffer_window);
       if (for_deletion && XFRAME (MB_frame) != of)
@@ -636,6 +640,7 @@ read_minibuf (Lisp_Object map, Lisp_Object initial, Lisp_Object prompt,
   mini_frame = WINDOW_FRAME (XWINDOW (minibuf_window));
 
   if (minibuf_level > 1
+      && WINDOW_LIVE_P (XFRAME (MB_frame)->minibuffer_window)
       && !EQ (XWINDOW (XFRAME (selected_frame)->minibuffer_window)->frame,
               MB_frame)
       && minibuf_moves_frame_when_opened ()
@@ -908,11 +913,13 @@ read_minibuf (Lisp_Object map, Lisp_Object initial, Lisp_Object prompt,
   unbind_to (count, Qnil);
 
   /* Switch the frame back to the calling frame.  */
-  if ((!EQ (selected_frame, calling_frame)
-       || !EQ (XWINDOW (XFRAME (calling_frame)->minibuffer_window)->frame,
-               calling_frame))
-      && FRAMEP (calling_frame)
-      && FRAME_LIVE_P (XFRAME (calling_frame)))
+  if (FRAMEP (calling_frame)
+      && FRAME_LIVE_P (XFRAME (calling_frame))
+      && (!EQ (selected_frame, calling_frame)
+          || (WINDOW_LIVE_P (XFRAME (calling_frame)->minibuffer_window)
+              && !EQ (XWINDOW (XFRAME (calling_frame)->minibuffer_window)
+                      ->frame,
+                      calling_frame))))
     call2 (intern ("select-frame-set-input-focus"), calling_frame, Qnil);
 
   /* Add the value to the appropriate history list, if any.  This is
@@ -1056,10 +1063,13 @@ read_minibuf_unwind (void)
     {
       f = XFRAME (exp_MB_frame);
       window = f->minibuffer_window;
-      w = XWINDOW (window);
-      if (EQ (w->frame, exp_MB_frame)
-          && EQ (w->contents, nth_minibuffer (minibuf_level)))
-        goto found;
+      if (WINDOW_LIVE_P (window))
+        {
+          w = XWINDOW (window);
+          if (EQ (w->frame, exp_MB_frame)
+              && EQ (w->contents, nth_minibuffer (minibuf_level)))
+            goto found;
+        }
     }
   return; /* expired minibuffer not found.  Maybe we should output an
              error, here. */