Update the documentation about labeled (locked) narrowing

* src/xdisp.c (syms_of_xdisp) <fontification-functions>: Update
docstring.

* src/keyboard.c (syms_of_keyboard) <pre-command-hook>:
(syms_of_keyboard) <post-command-hook>: Update docstring.

* src/editfns.c:
(narrowing_locks): Explain why an alist is used instead of a
buffer-local variable.
(reset_outermost_narrowings): Point to recipes that demonstrate
why it is necessary to restore the user narrowing bounds when
redisplay starts.
(Fwiden): Update docstring.
(Fnarrow_to_region): Update docstring.
(Finternal__lock_narrowing): Update docstring.
(Finternal__unlock_narrowing): Update docstring.
(Fsave_restriction): Update docstring.

* src/buffer.c (syms_of_buffer)
<long-line-optimizations-region-size>: Update docstring.
(syms_of_buffer) <long-line-optimizations-bol-search-limit>:
Update docstring.

* lisp/subr.el (with-narrowing): Update docstring.
(without-narrowing): Update docstring.

* etc/NEWS: Mention the 'long-line-optimizations-region-size' and
'long-line-optimizations-bol-search-limit' options.
Announce the 'with-narrowing' and 'without-narrowing' forms.

* doc/lispref/positions.texi (Narrowing): Update the documentation
of 'narrow-to-region', 'widen' and 'save-restriction'.  Document
the 'with-narrowing' and 'without-narrowing' special forms.

* doc/lispref/display.texi (Auto Faces): Update the documentation.

* doc/lispref/commands.texi (Command Overview): Document the fact
that the buffer is narrowed around 'pre-command-hook' and
'post-command-hook' when the buffer text includes very long lines.

1 files changed, 10 insertions, 14 deletions

diff --git a/src/keyboard.c b/src/keyboard.c
index 4417aa97d28..1d0b907bd8e 100644
--- a/src/keyboard.c
+++ b/src/keyboard.c
@@ -12731,13 +12731,11 @@ If an unhandled error happens in running this hook, the function in
 which the error occurred is unconditionally removed, since otherwise
 the error might happen repeatedly and make Emacs nonfunctional.
 
-Note that, when the current buffer contains one or more lines whose
-length is above `long-line-threshold', these hook functions are called
-with the buffer narrowed to a small portion around point (whose size
-is specified by `long-line-locked-narrowing-region-size'), and the
-narrowing is locked (see `narrowing-lock'), so that these hook
-functions cannot use `widen' to gain access to other portions of
-buffer text.
+Note that, when `long-line-optimizations-p' is non-nil in the buffer,
+these functions are called as if they were in a `with-narrowing' form,
+with a `long-line-optimizations-in-command-hooks' label and with the
+buffer narrowed to a portion around point whose size is specified by
+`long-line-optimizations-region-size'.
 
 See also `post-command-hook'.  */);
   Vpre_command_hook = Qnil;
@@ -12753,13 +12751,11 @@ It is a bad idea to use this hook for expensive processing.  If
 unavoidable, wrap your code in `(while-no-input (redisplay) CODE)' to
 avoid making Emacs unresponsive while the user types.
 
-Note that, when the current buffer contains one or more lines whose
-length is above `long-line-threshold', these hook functions are called
-with the buffer narrowed to a small portion around point (whose size
-is specified by `long-line-locked-narrowing-region-size'), and the
-narrowing is locked (see `narrowing-lock'), so that these hook
-functions cannot use `widen' to gain access to other portions of
-buffer text.
+Note that, when `long-line-optimizations-p' is non-nil in the buffer,
+these functions are called as if they were in a `with-narrowing' form,
+with a `long-line-optimizations-in-command-hooks' label and with the
+buffer narrowed to a portion around point whose size is specified by
+`long-line-optimizations-region-size'.
 
 See also `pre-command-hook'.  */);
   Vpost_command_hook = Qnil;