Merge from origin/emacs-27

7ceb45f61f (origin/emacs-27) Reformulate c-end-of-macro, handling mul...
888ffd960c Fix unexec failure on macOS 10.15.4
b392c9f365 Fix 'reverse-region' when less than one line is in region
7448834f73 Correct default regexp in 'package-menu-hide-package'
faada7ca42 Remove obsolete menu entry "Redisplay buffer"
78d76cd93c Remove redundant 'msft' compilation error rule (bug#39595)
75a9eee8b8 ; * src/editfns.c (Fbuffer_size): Tiny clarification.
4d8d25d641 * doc/lispref/variables.texi (special-variable-p): Clarify...
9f6a4bbcc9 Remove the optional KEEP-ORDER argument to regexp-opt
d1e8ce8bb6 Make after-change-functions called from call-process get t...

# Conflicts:
#	etc/NEWS

2 files changed, 7 insertions, 6 deletions

diff --git a/doc/lispref/searching.texi b/doc/lispref/searching.texi
index 5f4509a8b43..1f6db0643e8 100644
--- a/doc/lispref/searching.texi
+++ b/doc/lispref/searching.texi
@@ -1745,7 +1745,7 @@ any special characters.
 @end defun
 
 @cindex optimize regexp
-@defun regexp-opt strings &optional paren keep-order
+@defun regexp-opt strings &optional paren
 This function returns an efficient regular expression that will match
 any of the strings in the list @var{strings}.  This is useful when you
 need to make matching or searching as fast as possible---for example,
@@ -1783,11 +1783,8 @@ if it is necessary to ensure that a postfix operator appended to
 it will apply to the whole expression.
 @end table
 
-The optional argument @var{keep-order}, if non-@code{nil}, forces the
-match to be performed in the order given, as if the strings were made
-into a regexp by joining them with the @samp{\|} operator.  If nil or
-omitted, the returned regexp will always match the longest string
-possible.
+The returned regexp is ordered in such a way that it will always match
+the longest string possible.
 
 Up to reordering, the resulting regexp of @code{regexp-opt} is
 equivalent to but usually more efficient than that of a simplified
diff --git a/doc/lispref/variables.texi b/doc/lispref/variables.texi
index 1e357754abe..35eb4d59fb0 100644
--- a/doc/lispref/variables.texi
+++ b/doc/lispref/variables.texi
@@ -1229,6 +1229,10 @@ This function returns non-@code{nil} if @var{symbol} is a special
 variable (i.e., it has a @code{defvar}, @code{defcustom}, or
 @code{defconst} variable definition).  Otherwise, the return value is
 @code{nil}.
+
+Note that since this is a function, it can only return
+non-@code{nil} for variables which are permanently special, but not
+for those that are only special in the current lexical scope.
 @end defun
 
   The use of a special variable as a formal argument in a function is