emacs-28 e0bac17bbc: Mention face quirks after the final line in the lispref manual

[Lars Ingebrigtsen]

branch: emacs-28
commit e0bac17bbc51fc53d3555011b540b775942961d9
Author: Lars Ingebrigtsen <larsi@gnus.org>
Commit: Lars Ingebrigtsen <larsi@gnus.org>

    Mention face quirks after the final line in the lispref manual
    
    * doc/lispref/display.texi (Face Attributes): Mention the quirks
    about point after the final line (bug#56011).
---
 doc/lispref/display.texi | 7 +++++++
 1 file changed, 7 insertions(+)

diff --git a/doc/lispref/display.texi b/doc/lispref/display.texi
index 1147ba112a..404cf1b247 100644
--- a/doc/lispref/display.texi
+++ b/doc/lispref/display.texi
@@ -2593,6 +2593,13 @@ doesn't specify an explicit value for a face, the value 
from the
 original face definition by @code{defface} is inherited
 (@pxref{Defining Faces}).
 
+Some modes, like @code{hl-line-mode}, use a face with an
+@code{:extend} property to mark the entire current line.  Note,
+however, that Emacs will always allow you to move point after the
+final character in a buffer, and if the buffer ends with a newline
+character, point can be placed on what is seemingly a line at the end
+of the buffer---but Emacs can't highlight that ``line'', because it
+doesn't really exist.
 @end table
 
 @defun font-family-list &optional frame