Subject: 31.0.50; tab-line mode adds extra space during in-buffer completion

From: Arash Esbati <[email-masked]>
Date: Mon, 20 Jan 2025 14:18:14 +0100

Hi all,

it seems that some recent changes in tab-line mode produce additional
vertical space during in-buffer completion.  To reproduce, start with
"emacs -Q" and then eval:

(progn
  (package-initialize t)
  (package-activate 'corfu)
  (global-corfu-mode)
  (setq tab-always-indent 'complete))

Now enter '(def' and hit TAB which gives for me:

Now activate tab-line mode and eval:

(global-tab-line-mode 1)

and hit TAB again after '(def' which now looks like this:

Note the extra line between the text and the candidates.  I haven't
bisect this, but this behavior is new.

Best, Arash

In GNU Emacs 31.0.50 (build 1, aarch64-apple-darwin24.2.0, NS
 appkit-2575.30 Version 15.2 (Build 24C101)) of 2025-01-20 built on
 MacMutant.local
Repository revision: 458135155675a29a2c064998afc0cb416cd38b52
Repository branch: master
Windowing system distributor 'Apple', version 10.3.2575
System Description:  macOS 15.2

Configured using:
 'configure --with-ns --without-pop --without-mailutils --with-threads
 --with-modules --with-native-compilation --without-compress-install
 'CFLAGS=-O2 -g0 -pipe '
 'CPPFLAGS=-I/opt/homebrew/Cellar/gcc/14.2.0_1/include
 -I/opt/homebrew/Cellar/libgccjit/14.2.0_1/include
 -I/opt/homebrew/Cellar/gmp/6.3.0/include
 -I/opt/homebrew/Cellar/libxml2/2.13.5/include '
 'LDFLAGS=-L/opt/homebrew/Cellar/gcc/14.2.0_1/lib/gcc/current
 -L/opt/homebrew/Cellar/gmp/6.3.0/lib
 -L/opt/homebrew/Cellar/libxml2/2.13.5/lib ''

Configured features:
ACL GLIB GMP GNUTLS LCMS2 LIBXML2 MODULES NATIVE_COMP NOTIFY KQUEUE NS
PDUMPER PNG RSVG SQLITE3 THREADS TOOLKIT_SCROLL_BARS TREE_SITTER WEBP
XIM ZLIB

Important settings:
  value of $LANG: en_US.UTF-8
  locale-coding-system: utf-8-unix