bug#53216: 27.2; last line may be hidden in multi-line message

bug#53216: 27.2; last line may be hidden in multi-line message

[awrhygty]

Evaluate the form below and type 't', multi-line message is shown.
But I only see line '9' and line '10'.
The last line '11' is not shown.

(let ((buf (generate-new-buffer "tmp"))
      (map (make-sparse-keymap))
      (func (lambda ()
              (interactive)
              (message (propertize "1\n2\n3\n4\n5\n6\n7\n8\n9\n10\n11"
                                   'face '(:height 5.0))))))
  (switch-to-buffer buf)
  (define-key map "t" func)
  (use-local-map map))



In GNU Emacs 27.2 (build 1, x86_64-w64-mingw32)
 of 2021-03-26 built on CIRROCUMULUS
Repository revision: deef5efafb70f4b171265b896505b92b6eef24e6
Repository branch: HEAD
Windowing system distributor 'Microsoft Corp.', version 10.0.19043
System Description: Microsoft Windows 10 Pro (v10.0.2009.19043.1415)

Recent messages:

Configured using:
 'configure --without-dbus --host=x86_64-w64-mingw32
 --without-compress-install 'CFLAGS=-O2 -static''

Configured features:
XPM JPEG TIFF GIF PNG RSVG SOUND NOTIFY W32NOTIFY ACL GNUTLS LIBXML2
HARFBUZZ ZLIB TOOLKIT_SCROLL_BARS MODULES THREADS JSON PDUMPER LCMS2 GMP

Important settings:
  value of $LANG: JPN
  locale-coding-system: cp932

Major mode: Lisp Interaction

Minor modes in effect:
  tooltip-mode: t
  global-eldoc-mode: t
  eldoc-mode: t
  electric-indent-mode: t
  mouse-wheel-mode: t
  tool-bar-mode: t
  menu-bar-mode: t
  file-name-shadow-mode: t
  global-font-lock-mode: t
  font-lock-mode: t
  blink-cursor-mode: t
  auto-composition-mode: t
  auto-encryption-mode: t
  auto-compression-mode: t
  line-number-mode: t
  transient-mark-mode: t

Load-path shadows:
None found.

Features:
(shadow sort mail-extr emacsbug message rmc puny dired dired-loaddefs
format-spec rfc822 mml easymenu mml-sec password-cache epa derived epg
epg-config gnus-util rmail rmail-loaddefs text-property-search time-date
subr-x seq byte-opt gv bytecomp byte-compile cconv mm-decode mm-bodies
mm-encode mail-parse rfc2231 mailabbrev gmm-utils mailheader cl-loaddefs
cl-lib sendmail rfc2047 rfc2045 ietf-drums mm-util mail-prsvr mail-utils
term/bobcat japan-util tooltip eldoc electric uniquify ediff-hook
vc-hooks lisp-float-type mwheel dos-w32 ls-lisp disp-table term/w32-win
w32-win w32-vars term/common-win tool-bar dnd fontset image regexp-opt
fringe tabulated-list replace newcomment text-mode elisp-mode lisp-mode
prog-mode register page tab-bar menu-bar rfn-eshadow isearch timer
select scroll-bar mouse jit-lock font-lock syntax facemenu font-core
term/tty-colors frame minibuffer cl-generic cham georgian utf-8-lang
misc-lang vietnamese tibetan thai tai-viet lao korean japanese eucjp-ms
cp51932 hebrew greek romanian slovak czech european ethiopic indian
cyrillic chinese composite charscript charprop case-table epa-hook
jka-cmpr-hook help simple abbrev obarray cl-preloaded nadvice loaddefs
button faces cus-face macroexp files text-properties overlay sha1 md5
base64 format env code-pages mule custom widget hashtable-print-readable
backquote threads w32notify w32 lcms2 multi-tty make-network-process
emacs)

Memory information:
((conses 16 49515 10626)
 (symbols 48 6089 1)
 (strings 32 16934 922)
 (string-bytes 1 523236)
 (vectors 16 10650)
 (vector-slots 8 207224 9832)
 (floats 8 22 47)
 (intervals 56 229 0)
 (buffers 1000 11))

bug#53216: 27.2; last line may be hidden in multi-line message

[Eli Zaretskii]

> From: awrhygty@outlook.com
> Date: Thu, 13 Jan 2022 02:06:10 +0900
> 
> 
> Evaluate the form below and type 't', multi-line message is shown.
> But I only see line '9' and line '10'.
> The last line '11' is not shown.
> 
> (let ((buf (generate-new-buffer "tmp"))
>       (map (make-sparse-keymap))
>       (func (lambda ()
>               (interactive)
>               (message (propertize "1\n2\n3\n4\n5\n6\n7\n8\n9\n10\n11"
>                                    'face '(:height 5.0))))))
>   (switch-to-buffer buf)
>   (define-key map "t" func)
>   (use-local-map map))

This is the expected behavior; see the variable
max-mini-window-height.

Closing.

bug#53216: 27.2; last line may be hidden in multi-line message

[martin rudalics]

[-- Attachment #1: Type: text/plain, Size: 648 bytes --]

 > Evaluate the form below and type 't', multi-line message is shown.
 > But I only see line '9' and line '10'.
 > The last line '11' is not shown.
 >
 > (let ((buf (generate-new-buffer "tmp"))
 >        (map (make-sparse-keymap))
 >        (func (lambda ()
 >                (interactive)
 >                (message (propertize "1\n2\n3\n4\n5\n6\n7\n8\n9\n10\n11"
 >                                     'face '(:height 5.0))))))
 >    (switch-to-buffer buf)
 >    (define-key map "t" func)
 >    (use-local-map map))

The attached patch seems to fix this here but
'redisplay-adhoc-scroll-in-resize-mini-windows' is terra incognita for
me.

martin

[-- Attachment #2: xdisp.c.diff --]
[-- Type: text/x-patch, Size: 579 bytes --]

@@ -12295,7 +12299,7 @@ resize_mini_window (struct window *w, bool exact_p)
                  don't force w->start to be at the beginning of a screen
                  line, important parts of the stuff in the mini-window,
                  such as user prompt, will be hidden from view.  */
-              move_it_by_lines (&it, 0);
+	      move_it_by_lines (&it, last_height > 0 ? 1 : 0);
               start = it.current.pos;
               /* Prevent redisplay_window from recentering, and thus from
                  overriding the window-start point we computed here.  */