Variable: header-line-indent-mode-hook
header-line-indent-mode-hook is a customizable variable defined in
display-line-numbers.el.gz.
Value
nil
Documentation
Hook run after entering or leaving header-line-indent-mode(var)/header-line-indent-mode(fun).
No problems result if this variable is not bound.
add-hook automatically binds it. (This is true for all hook variables.)
Source Code
;; Defined in /usr/src/emacs/lisp/display-line-numbers.el.gz