diff --git a/doc/lispref/maps.texi b/doc/lispref/maps.texi
index 6ae98da49c7..f1a7fe258d5 100644
--- a/doc/lispref/maps.texi
+++ b/doc/lispref/maps.texi
@@ -30,7 +30,7 @@ A sparse keymap for subcommands of the prefix @kbd{C-x a}.@*
 @xref{Defining Abbrevs,,, emacs, The GNU Emacs Manual}.
 
 @item button-buffer-map
-A sparse keymap useful for buffers containing buffers.@*
+A sparse keymap useful for buffers containing buttons.@*
 You may want to use this as a parent keymap.  @xref{Buttons}.
 
 @item button-map
diff --git a/doc/misc/gnus.texi b/doc/misc/gnus.texi
index 71d548f3cee..200b68d2059 100644
--- a/doc/misc/gnus.texi
+++ b/doc/misc/gnus.texi
@@ -14374,6 +14374,8 @@ where you would put a @samp{SOCKS} wrapper for instance.
 @vindex nntp-address
 The address of the @acronym{NNTP} server.
 
+@cindex nntps
+@cindex snews
 @item nntp-port-number
 @vindex nntp-port-number
 Port number to connect to the @acronym{NNTP} server.  The default is
diff --git a/doc/misc/tramp.texi b/doc/misc/tramp.texi
index e1d50972583..943f6da7b04 100644
--- a/doc/misc/tramp.texi
+++ b/doc/misc/tramp.texi
@@ -1572,10 +1572,10 @@ for accessing the system storage, you should use it.
 
 @vindex tramp-sshfs-program
 On local hosts which have installed the @command{sshfs} client for
-mounting a file system based on @command{sftp}, this method can be
-used, see
-@uref{https://github.com/libfuse/sshfs/blob/master/README.rst/}.  If
-the @command{sshfs} program isn't found in your @env{PATH} environment
+mounting a file system based on the @command{sftp} subsystem of
+@command{ssh}, this method can be used, see
+@uref{https://github.com/libfuse/sshfs/blob/master/README.md}.  If the
+@command{sshfs} program isn't found in your @env{PATH} environment
 variable, you can tell @value{tramp} its absolute path via the user
 option @code{tramp-sshfs-program}.
 
diff --git a/etc/DEBUG b/etc/DEBUG
index 77fe78e32fd..a9ed8b26b64 100644
--- a/etc/DEBUG
+++ b/etc/DEBUG
@@ -283,7 +283,10 @@ breakpoints in advance.  GDB 13.1 changed the way C-c and C-BREAK are
 handled on Windows, so with those newer versions, you don't need the
 "set new-console 1" setting to be able to interrupt Emacs by typing
 C-c or C-BREAK into the console window from which you started Emacs
-and where you interact with GDB.
+and where you interact with GDB.  Instead, make sure that SIGINT will
+stop Emacs under the debugger:
+
+  (gdb) handle SIGINT stop nopass
 
 ** Examining Lisp object values.
 
diff --git a/etc/PROBLEMS b/etc/PROBLEMS
index 30506b3c87a..8de12a78613 100644
--- a/etc/PROBLEMS
+++ b/etc/PROBLEMS
@@ -1588,6 +1588,12 @@ https://debbugs.gnu.org/cgi/bugreport.cgi?bug=22000,
 https://debbugs.gnu.org/cgi/bugreport.cgi?bug=22898 and
 https://lists.gnu.org/r/emacs-devel/2016-07/msg00154.html.
 
+*** In Emacs built with GTK+ toolkit, menu-bar background becomes transparent.
+
+This happens when 'alpha-background' is less than 100.  This is due a
+GTK limitation, for which no workaround is currently known,
+unfortunately.
+
 *** Metacity: Resizing Emacs or ALT-Tab causes X to be unresponsive.
 
 This happens sometimes when using Metacity.  Resizing Emacs or ALT-Tab:bing
diff --git a/etc/TODO b/etc/TODO
index fa19d9f96d9..1a05f65abb6 100644
--- a/etc/TODO
+++ b/etc/TODO
@@ -35,6 +35,24 @@ is not always true.
 
 * High Priority Items
 
+** Overhaul the customization groups.
+The goal is to present new Emacs users with a reasonable and useful
+hierarchy of customization groups, thus allowing them to easily find a
+customization options they are looking for, by going down this
+hierarchy.
+
+The current customization groups (see "M-x customize-group RET RET") and
+their hierarchy are sporadic and do not systematically cover all the
+areas and domains of Emacs features.  They need to be extensively
+re-thought and overhauled.  One idea is to take the top-level chapters
+of the Emacs user manual and use those as customization groups, then
+define sub-groups using the sections.  Sub-sections could then be used
+where a third level of groups makes sense.  The place to define this
+hierarchy is mainly in cus-edit.el.
+
+Once the two- or three-level hierarchy of defgroups is defined, all the
+defcustom's should be audited and their groups redefined if necessary.
+
 ** Things related to elpa.gnu.org.
 We need to figure out how to best include GNU ELPA packages in the
 Emacs tarball before doing any of the items below.
diff --git a/lisp/gnus/gnus.el b/lisp/gnus/gnus.el
index 62a090bd9df..0d0e678309f 100644
--- a/lisp/gnus/gnus.el
+++ b/lisp/gnus/gnus.el
@@ -1402,9 +1402,14 @@ this variable.  I think."
 	    (string :tag "Address")
 	    (repeat :tag "Options"
 		    :inline t
-		    (list :format "%v"
-			  variable
-			  (sexp :tag "Value"))))))
+                    (radio
+		     (list :tag "Single var" :format "%v"
+			   variable
+			   (sexp :tag "Value"))
+                     (list :tag "Multiple var" :format "%v"
+			   variable
+                           variable
+			   (sexp :tag "Value")))))))
 
 (gnus-redefine-select-method-widget)
 
diff --git a/lisp/net/rcirc.el b/lisp/net/rcirc.el
index c41e2ec153f..33e4008fc0b 100644
--- a/lisp/net/rcirc.el
+++ b/lisp/net/rcirc.el
@@ -2448,7 +2448,8 @@ This function does not alter the INPUT string."
 
 (defun rcirc-next-active-buffer (arg)
   "Switch to the next rcirc buffer with activity.
-With prefix ARG, go to the next low priority buffer with activity."
+With prefix ARG, go to the next low priority buffer with activity.
+When there are no buffers with activity, bury all rcirc buffers."
   (interactive "P")
   (let* ((pair (rcirc-split-activity rcirc-activity))
          (lopri (car pair))
diff --git a/lisp/progmodes/compile.el b/lisp/progmodes/compile.el
index ac1042e21e6..6784a12fd63 100644
--- a/lisp/progmodes/compile.el
+++ b/lisp/progmodes/compile.el
@@ -61,16 +61,18 @@ If nil, use Emacs default."
 
 (defcustom compilation-transform-file-match-alist
   '(("/bin/[a-z]*sh\\'" nil))
-  "Alist of regexp/replacements to alter file names in compilation errors.
-If the replacement is nil, the file will not be considered an error
-after all.  If not nil, it should be a regexp replacement string.
+  "Alist of regexp/replacements to alter file names in compiler messages.
+If the replacement is nil, the matching message will not be considered
+an error or warning.  If not nil, it should be a replacement string
+for the matched regexp.
 
-When a replacement regexp is specified, the value of the file name used
-to locate the error is changed, but the compilation buffer still
-displays the original value.
+If a non-nil replacement is specified, the value of the matched file name
+used to locate the warning or error is modified using the replacement, but
+the compilation buffer still displays the original value.
 
-For example, to prepend a subdirectory \"bar/\" to all file names, add
-an entry matching \"\\\\=`\" and a replacement regexp of \"bar/\", i.e.:
+For example, to prepend a subdirectory \"bar/\" to all file names in
+compiler messages, add an entry matching \"\\\\=`\" and a replacement
+string of \"bar/\", i.e.:
 
     (\"\\\\=`\" \"bar/\")
 
@@ -803,10 +805,10 @@ Alternatively, FACE can evaluate to a property list of the
 form (face FACE PROP1 VAL1 PROP2 VAL2 ...), in which case all the
 listed text properties PROP# are given values VAL# as well.
 
-After identifying errors and warnings determined by this
+After identifying compilation errors and warnings determined by this
 variable, the `compilation-transform-file-match-alist' variable
 is then consulted.  It allows further transformations of the
-matched file names, and weeding out false positives."
+matched file names, and ignoring false positives."
   :type '(repeat (choice (symbol :tag "Predefined symbol")
 			 (sexp :tag "Error specification")))
   :link `(file-link :tag "example file"
diff --git a/lisp/progmodes/executable.el b/lisp/progmodes/executable.el
index cb4a5eedb80..97baf86e017 100644
--- a/lisp/progmodes/executable.el
+++ b/lisp/progmodes/executable.el
@@ -43,10 +43,9 @@
 ;; It also allows debugging scripts, with an adaptation of compile, as far
 ;; as interpreters give out meaningful error messages.
 
-;; Modes that use this should nconc `executable-map' to the end of their own
-;; keymap and `executable-font-lock-keywords' to the end of their own font
-;; lock keywords.  Their mode-setting commands should call
-;; `executable-set-magic'.
+;; Modes that use this should nconc `executable-font-lock-keywords' to
+;; the end of their own font lock keywords.  Their mode-setting commands
+;; should call `executable-set-magic'.
 
 ;;; Code:
 
diff --git a/lisp/time-stamp.el b/lisp/time-stamp.el
index 50d75ecac01..c9f451cb8cc 100644
--- a/lisp/time-stamp.el
+++ b/lisp/time-stamp.el
@@ -569,6 +569,8 @@ and all `time-stamp-format' compatibility."
 		     (setq field-width "1" flag-minimize t))
 		    ((eq cur-char ?_)
 		     (setq field-width "2" flag-pad-with-spaces t))))
+            (if (> (string-to-number field-width) 99)
+                (setq field-width (if flag-pad-with-zeros "099" "99")))
 	    (setq field-result
 	          (cond
 	           ((eq cur-char ?%)