master d92b725 2/6: Merge from origin/emacs-27

[Glenn Morris]

branch: master
commit d92b725ffc95b72b595818216b92184446245e7e
Merge: 843eb21 f60eb98
Author: Glenn Morris <rgm@gnu.org>
Commit: Glenn Morris <rgm@gnu.org>

    Merge from origin/emacs-27
    
    f60eb988f6 Fix typos and omissions for (elisp)Button Buffer Commands
    876b95bf90 Teach Rmail about NBSP in "Re:"
    
    # Conflicts:
    #   lisp/mail/rmail.el
---
 doc/lispref/display.texi | 6 +++---
 lisp/mail/rmail.el       | 4 ++--
 2 files changed, 5 insertions(+), 5 deletions(-)

diff --git a/doc/lispref/display.texi b/doc/lispref/display.texi
index f003d52..2e1b4a6 100644
--- a/doc/lispref/display.texi
+++ b/doc/lispref/display.texi
@@ -7056,11 +7056,11 @@ end of the buffer continues from the other end.  If
 @var{display-message} is non-@code{nil}, the button's help-echo string
 is displayed.  Any button with a non-@code{nil} @code{skip} property
 is skipped over.  Returns the button found, and signals an error if no
-buttons can be found.  If @var{no-error} in non-@code{nil}, return nil
+buttons can be found.  If @var{no-error} is non-@code{nil}, return nil
 instead of signaling the error.
 @end deffn
 
-@deffn Command backward-button n &optional wrap display-message
+@deffn Command backward-button n &optional wrap display-message no-error
 Move to the @var{n}th previous button, or @var{n}th next button if
 @var{n} is negative.  If @var{n} is zero, move to the start of any
 button at point.  If @var{wrap} is non-@code{nil}, moving past either
@@ -7068,7 +7068,7 @@ end of the buffer continues from the other end.  If
 @var{display-message} is non-@code{nil}, the button's help-echo string
 is displayed.  Any button with a non-@code{nil} @code{skip} property
 is skipped over.  Returns the button found, and signals an error if no
-buttons can be found.  If @var{no-error} in non-@code{nil}, return nil
+buttons can be found.  If @var{no-error} is non-@code{nil}, return nil
 instead of signaling the error.
 @end deffn
 
diff --git a/lisp/mail/rmail.el b/lisp/mail/rmail.el
index 2bd3ffa..c7960f8 100644
--- a/lisp/mail/rmail.el
+++ b/lisp/mail/rmail.el
@@ -551,7 +551,7 @@ Examples:
 (defvar rmail-reply-regexp
   (concat "\\`\\("
           rmail-re-abbrevs
-          "\\(([0-9]+)\\|\\[[0-9]+\\]\\|\\^[0-9]+\\)?[:：] *\\)*")
+          "\\(([0-9]+)\\|\\[[0-9]+\\]\\|\\^[0-9]+\\)?\u00a0*[:：] *\\)*")
   "Regexp to delete from Subject line before inserting `rmail-reply-prefix'.")
 
 (defcustom rmail-display-summary nil
@@ -3356,7 +3356,7 @@ whitespace, replacing whitespace runs with a single space 
and
 removing prefixes such as Re:, Fwd: and so on and mailing list
 tags such as [tag]."
   (let ((subject (or (rmail-get-header "Subject" msgnum) ""))
-       (regexp "\\`[ \t\n]*\\(\\(\\w\\{1,4\\}[:：]\\|\\[[^]]+]\\)[ \t\n]+\\)*"))
+       (regexp "\\`[ \t\n]*\\(\\(\\w\\{1,4\\}\u00a0*[:：]\\|\\[[^]]+]\\)[ 
\t\n]+\\)*"))
     (setq subject (rfc2047-decode-string subject))
     (setq subject (replace-regexp-in-string regexp "" subject))
     (replace-regexp-in-string "[ \t\n]+" " " subject)))