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, 19 insertions, 0 deletions

diff --git a/doc/lispref/minibuf.texi b/doc/lispref/minibuf.texi
index a2b6e145502..6c37fa92d6c 100644
--- a/doc/lispref/minibuf.texi
+++ b/doc/lispref/minibuf.texi
@@ -2402,6 +2402,25 @@ will not work.  If you want to prevent resizing of minibuffer windows
 when displaying long messages, bind the @code{message-truncate-lines}
 variable instead (@pxref{Echo Area Customization}).
 
+The option @code{resize-mini-windows} does not affect the behavior of
+minibuffer-only frames (@pxref{Frame Layout}).  The following option
+allows to automatically resize such frames as well.
+
+@defopt resize-mini-frames
+If this is @code{nil}, minibuffer-only frames are never resized
+automatically.
+
+If this is a function, that function is called with the
+minibuffer-only frame to be resized as sole argument.  At the time
+this function is called, the buffer of the minibuffer window of that
+frame is the buffer whose contents will be shown the next time that
+window is redisplayed.  The function is expected to fit the frame to
+the buffer in some appropriate way.
+
+Any other non-@code{nil} value means to resize minibuffer-only frames
+by calling @code{fit-frame-to-buffer} (@pxref{Resizing Windows}).
+@end defopt
+
 
 @node Minibuffer Contents
 @section Minibuffer Contents