Variable: mode-line-compact
mode-line-compact is a customizable variable defined in xdisp.c.
Value
nil
Documentation
Non-nil means that mode lines should be compact.
This means that repeating spaces will be replaced with a single space.
If this variable is long, only mode lines that are wider than the
currently selected window are compressed.
This variable was added, or its default value changed, in Emacs 28.1.
Probably introduced at or before Emacs version 28.1.
Source Code
// Defined in /usr/src/emacs/src/xdisp.c
DEFVAR_LISP ("mode-line-compact", Vmode_line_compact,
doc: /* Non-nil means that mode lines should be compact.
This means that repeating spaces will be replaced with a single space.
If this variable is `long', only mode lines that are wider than the
currently selected window are compressed. */);