Rewrite minibuffer window resizing code

* src/frame.c (resize_mini_frames): New variable.
* src/window.c (resize_mini_window_apply): New function.
(grow_mini_window, shrink_mini_window): Remove PIXELWISE
argument.  Call resize_mini_window_apply to apply changes.
(Fresize_mini_window_internal): Call resize_mini_window_apply
to apply changes.
(Qwindow__resize_mini_frame): New symbol.
* src/window.h (grow_mini_window, shrink_mini_window): Adjust
external declarations.
* src/xdisp.c (resize_mini_window): For minibuffer-only frames
call 'window--resize-mini-frame' if resize_mini_frames is
non-nil.  Offload parts of logic to grow_mini_window and
shrink_mini_window which are now called without the PIXELWISE
argument.
(Vresize_mini_windows): Mention 'resize-mini-frames' in
doc-string.
* lisp/cus-start.el (resize-mini-frames): Add customization
support.
* lisp/window.el (window--resize-mini-window): Simplify code.
(window--resize-mini-frame): New function.
* doc/lispref/minibuf.texi (Minibuffer Windows): Describe new
option 'resize-mini-frames'.
* etc/NEWS: Mention new option 'resize-mini-frames'.

1 files changed, 13 insertions, 0 deletions

diff --git a/src/frame.c b/src/frame.c
index c336369dbb5..46bdf222315 100644
--- a/src/frame.c
+++ b/src/frame.c
@@ -6079,6 +6079,19 @@ setting this variable does not change that frame's previous association.
 
 This variable is local to the current terminal and cannot be buffer-local.  */);
 
+  DEFVAR_LISP ("resize-mini-frames", resize_mini_frames,
+    doc: /* Non-nil means resize minibuffer-only frames automatically.
+If this is nil, do not resize minibuffer-only frames automatically.
+
+If this is a function, call that function with the minibuffer-only
+frame that shall be resized as sole argument.  The buffer of the root
+window of that frame is the buffer whose text will be eventually shown
+in the minibuffer window.
+
+Any other non-nil value means to resize minibuffer-only frames by
+calling `fit-frame-to-buffer'.  */);
+  resize_mini_frames = Qnil;
+
   DEFVAR_LISP ("focus-follows-mouse", focus_follows_mouse,
                doc: /* Non-nil if window system changes focus when you move the mouse.
 You should set this variable to tell Emacs how your window manager