Fix handling of 'minibuffer' frame parameter for tty frames

* src/frame.c (make_terminal_frame): Fix handling of
'minibuffer' frame parameter for tty child frames.  Support
'minibuffer-only' child frames.

(cherry picked from commit b7dc4ba213e3c1aac5637546e48088206b6e91eb)

diff --git a/src/frame.c b/src/frame.c
index 1e3713511979f3cdfec894cfb69c6d7bf61d7333..3cfc9d0bf552df7af279aad4c748958df76f59f7 100644 (file)
--- a/src/frame.c
+++ b/src/frame.c
@@ -1289,6 +1289,7 @@ make_terminal_frame (struct terminal *terminal, Lisp_Object parent,
     error ("Terminal is not live, can't create new frames on it");
 
   struct frame *f;
+
   if (NILP (parent))
     f = make_frame (true);
   else
@@ -1297,16 +1298,60 @@ make_terminal_frame (struct terminal *terminal, Lisp_Object parent,
 
       f = NULL;
       Lisp_Object mini = Fassq (Qminibuffer, params);
+
+      /* Handling the minibuffer parameter on a tty is different from
+        its handling on a GUI.  On a GUI any "client frame" can have,
+        in principle, its minibuffer window on any "minibuffer frame" -
+        a frame that has a minibuffer window.  If necessary, Emacs
+        tells the window manager to make the minibuffer frame visible,
+        raise it and give it input focus.
+
+        On a tty there's no window manager; so Emacs itself has to make
+        such a minibuffer frame visible, raise and focus it.  Since a
+        tty can show only one root frame (a frame that doesn't have a
+        parent frame) at any time, any client frame shown on a tty must
+        have a minibuffer frame whose root frame is the root frame of
+        that client frame.  If that minibuffer frame is a child frame,
+        Emacs will automatically make it visible, raise it and give it
+        input focus, if necessary.
+
+        Two trivial consequences of these observations for ttys are:
+
+        - A root frame cannot be the minibuffer frame of another root
+          frame.
+
+        - Since a child frame cannot be created before its parent
+           frame, each root frame must have its own minibuffer window.
+
+         The situation may change as soon as we can delete and create
+         minibuffer windows on the fly.  */
       if (CONSP (mini))
        {
          mini = Fcdr (mini);
-         struct kboard *kb = FRAME_KBOARD (XFRAME (parent));
+
          if (EQ (mini, Qnone) || NILP (mini))
-           f = make_frame_without_minibuffer (Qnil, kb, Qnil);
+           {
+             mini = root_frame (XFRAME (parent))->minibuffer_window;
+             f = make_frame (false);
+             fset_minibuffer_window (f, mini);
+             store_frame_param (f, Qminibuffer, mini);
+           }
          else if (EQ (mini, Qonly))
-           error ("minibuffer-only child frames are not implemented");
+           f = make_minibuffer_frame ();
          else if (WINDOWP (mini))
-           f = make_frame_without_minibuffer (mini, kb, Qnil);
+           {
+             if (!WINDOW_LIVE_P (mini)
+                 || !MINI_WINDOW_P (XWINDOW (mini))
+                 || (root_frame (WINDOW_XFRAME (XWINDOW (mini)))
+                     != root_frame (XFRAME (parent))))
+               error ("The `minibuffer' parameter does not specify a valid minibuffer window");
+             else
+               {
+                 f = make_frame (false);
+                 fset_minibuffer_window (f, mini);
+                 store_frame_param (f, Qminibuffer, mini);
+               }
+           }
        }
 
       if (f == NULL)