Make frames record when their selected window was the mini-window

When a frame in this state is selected again by Fselect_frame (but not by
Fselect_window), the mini-window rather than the frame's currently selected
window, is chosen for selection, should there still be an active minibuffer in
it.

This fixes bug #48674.

* src/frame.h (struct frame): Add new boolean field select_mini_window_flag.

* src/frame.c (make_frame): Initialize select_mini_window_flag to false.
(do_switch_frame): Set the new flag appropriately for the old frame, and
process the new frame's setting of this flag, before setting it to false.

* src/window.c (select_window): Set f->select_mini_window_flag to false.
(Fset_frame_selected_window, Fdelete_other_windows_internal)
(Fdelete_window_internal): Add comments clarifying that there is no clearing
of f->select_mini_window_flag in these functions.

1 files changed, 10 insertions, 0 deletions

diff --git a/src/window.c b/src/window.c
index 9961c54161d..2d98ae5f156 100644
--- a/src/window.c
+++ b/src/window.c
@@ -468,6 +468,7 @@ Return WINDOW.  */)
   else
     {
       fset_selected_window (XFRAME (frame), window);
+      /* Don't clear FRAME's select_mini_window_flag here.  */
       return window;
     }
 }
@@ -517,6 +518,9 @@ select_window (Lisp_Object window, Lisp_Object norecord,
     /* Do not select a tooltip window (Bug#47207).  */
     error ("Cannot select a tooltip window");
 
+  /* We deinitely want to select WINDOW, not the mini-window.  */
+  f->select_mini_window_flag = false;
+
   /* Make the selected window's buffer current.  */
   Fset_buffer (w->contents);
 
@@ -3242,6 +3246,9 @@ window-start value is reasonable when this function is called.  */)
           if (EQ (selected_frame, w->frame))
             Fselect_window (window, Qnil);
           else
+            /* Do not clear f->select_mini_window_flag here.  If the
+               last selected window on F was an active minibuffer, we
+               want to return to it on a later Fselect_frame.  */
             fset_selected_window (f, window);
         }
     }
@@ -5153,6 +5160,9 @@ Signal an error when WINDOW is the only window on its frame.  */)
           if (EQ (FRAME_SELECTED_WINDOW (f), selected_window))
             Fselect_window (new_selected_window, Qt);
           else
+            /* Do not clear f->select_mini_window_flag here.  If the
+               last selected window on F was an active minibuffer, we
+               want to return to it on a later Fselect_frame.  */
             fset_selected_window (f, new_selected_window);
 
           unblock_input ();