Adjust naming convention for dependent Gnus sessions

* doc/misc/gnus.texi (Child Gnusae): Rename node from "Slave
Gnusae" and adjust wording.  Also remove at least one joke.

* lisp/gnus/gnus-start.el (gnus-no-server-1, gnus-1)
(gnus-setup-news, gnus-save-newsrc-file): Adjust parameter names.
(gnus-child-mode): Rename and add alias.
(gnus-child-save-newsrc): Rename.
(gnus-parent-read-child-newsrc): Ditto.

* lisp/gnus/gnus-group.el (gnus-group-mode)
(gnus-group-get-new-news): Ditto.

* lisp/gnus/gnus-agent.el (gnus-child-unplugged): Rename function
from gnus-slave-unplugged (and add the latter as an obsolete alias).

* lisp/gnus/gnus.el (gnus-other-frame-function): Adjust function
names in the defcustom to new naming scheme.
(gnus-other-frame-resume-function): Ditto.
(gnus): Adjust parameter names.

7 files changed, 116 insertions, 93 deletions

diff --git a/doc/misc/gnus.texi b/doc/misc/gnus.texi
index 718e269fc86..294d9590bc9 100644
--- a/doc/misc/gnus.texi
+++ b/doc/misc/gnus.texi
@@ -436,7 +436,7 @@ Starting Gnus
 
 * Finding the News::            Choosing a method for getting news.
 * The Server is Down::          How can I read my mail then?
-* Slave Gnusae::                You can have more than one Gnus active at a time.
+* Child Gnusae::                You can have more than one Gnus active at a time.
 * Fetching a Group::            Starting Gnus just to read a group.
 * New Groups::                  What is Gnus supposed to do with new groups?
 * Changing Servers::            You may want to move from one server to another.
@@ -976,7 +976,7 @@ terminology section (@pxref{Terminology}).
 @menu
 * Finding the News::      Choosing a method for getting news.
 * The Server is Down::    How can I read my mail then?
-* Slave Gnusae::          You can have more than one Gnus active at a time.
+* Child Gnusae::          You can have more than one Gnus active at a time.
 * New Groups::            What is Gnus supposed to do with new groups?
 * Changing Servers::      You may want to move from one server to another.
 * Startup Files::         Those pesky startup files---@file{.newsrc}.
@@ -1090,9 +1090,9 @@ your primary server---instead, it will just activate all groups on level
 levels.)  Also @pxref{Group Levels}.
 
 
-@node Slave Gnusae
-@section Slave Gnusae
-@cindex slave
+@node Child Gnusae
+@section Child Gnusae
+@cindex child
 
 You might want to run more than one Emacs with more than one Gnus at the
 same time.  If you are using different @file{.newsrc} files (e.g., if you
@@ -1103,31 +1103,27 @@ The problem appears when you want to run two Gnusae that use the same
 @file{.newsrc} file.
 
 To work around that problem some, we here at the Think-Tank at the Gnus
-Towers have come up with a new concept: @dfn{Masters} and
-@dfn{slaves}.  (We have applied for a patent on this concept, and have
-taken out a copyright on those words.  If you wish to use those words in
-conjunction with each other, you have to send $1 per usage instance to
-me.  Usage of the patent (@dfn{Master/Slave Relationships In Computer
-Applications}) will be much more expensive, of course.)
-
-@findex gnus-slave
+Towers have come up with a new concept: @dfn{Parents} and
+@dfn{children}.
+
+@findex gnus-child
 Anyway, you start one Gnus up the normal way with @kbd{M-x gnus} (or
-however you do it).  Each subsequent slave Gnusae should be started with
-@kbd{M-x gnus-slave}.  These slaves won't save normal @file{.newsrc}
-files, but instead save @dfn{slave files} that contain information only
-on what groups have been read in the slave session.  When a master Gnus
-starts, it will read (and delete) these slave files, incorporating all
-information from them.  (The slave files will be read in the sequence
+however you do it).  Each subsequent child Gnusae should be started with
+@kbd{M-x gnus-child}.  These children won't save normal @file{.newsrc}
+files, but instead save @dfn{child files} that contain information only
+on what groups have been read in the child session.  When a parent Gnus
+starts, it will read (and delete) these child files, incorporating all
+information from them.  (The child files will be read in the sequence
 they were created, so the latest changes will have precedence.)
 
-Information from the slave files has, of course, precedence over the
-information in the normal (i.e., master) @file{.newsrc} file.
+Information from the child files has, of course, precedence over the
+information in the normal (i.e., parent) @file{.newsrc} file.
 
-If the @file{.newsrc*} files have not been saved in the master when the
-slave starts, you may be prompted as to whether to read an auto-save
-file.  If you answer ``yes'', the unsaved changes to the master will be
-incorporated into the slave.  If you answer ``no'', the slave may see some
-messages as unread that have been read in the master.
+If the @file{.newsrc*} files have not been saved in the parent when the
+child starts, you may be prompted as to whether to read an auto-save
+file.  If you answer ``yes'', the unsaved changes to the parent will be
+incorporated into the child.  If you answer ``no'', the child may see some
+messages as unread that have been read in the parent.
 
 
 
@@ -28487,9 +28483,9 @@ entry.
 The format spec @code{%C} for positioning point has changed to @code{%*}.
 
 @item
-@code{gnus-slave-unplugged}
+@code{gnus-child-unplugged}
 
-A new command which starts Gnus offline in slave mode.
+A new command which starts Gnus offline in child mode.
 
 @end itemize
 
diff --git a/etc/NEWS b/etc/NEWS
index 2afd4dee34f..4fdfcf95512 100644
--- a/etc/NEWS
+++ b/etc/NEWS
@@ -207,6 +207,12 @@ Bookmark locations can refer to VC directory buffers.
 
 ** Gnus
 
++++
+*** The name of dependent Gnus sessions has changed from "slave" to "child".
+The names of the commands 'gnus-slave', 'gnus-slave-no-server' and
+'gnus-slave-unplugged' have changed to 'gnus-child',
+'gnus-child-no-server' and 'gnus-child-unplugged' respectively.
+
 ---
 *** Change to default value of 'message-draft-headers' user option.
 The 'Date' symbol has been removed from the default value, meaning that
diff --git a/lisp/gnus/gnus-agent.el b/lisp/gnus/gnus-agent.el
index 1ed5000eb36..a617429de13 100644
--- a/lisp/gnus/gnus-agent.el
+++ b/lisp/gnus/gnus-agent.el
@@ -603,11 +603,18 @@ manipulated as follows:
   (gnus))
 
 ;;;###autoload
-(defun gnus-slave-unplugged (&optional arg)
-  "Read news as a slave unplugged."
+(defun gnus-child-unplugged (&optional arg)
+  "Read news as a child unplugged."
   (interactive "P")
   (setq gnus-plugged nil)
-  (gnus arg nil 'slave))
+  (gnus arg nil 'child))
+
+;;;###autoload
+(define-obsolete-function-alias 'gnus-slave-unplugged #'gnus-child-unplugged
+  "28.1")
+
+
+
 
 ;;;###autoload
 (defun gnus-agentize ()
diff --git a/lisp/gnus/gnus-group.el b/lisp/gnus/gnus-group.el
index da7db589ec3..b207c4f1e06 100644
--- a/lisp/gnus/gnus-group.el
+++ b/lisp/gnus/gnus-group.el
@@ -1129,8 +1129,8 @@ The following commands are available:
   (gnus-update-group-mark-positions)
   (when gnus-use-undo
     (gnus-undo-mode 1))
-  (when gnus-slave
-    (gnus-slave-mode)))
+  (when gnus-child
+    (gnus-child-mode)))
 
 (defun gnus-update-group-mark-positions ()
   (save-excursion
@@ -4024,9 +4024,9 @@ otherwise all levels below ARG will be scanned too."
     (gnus-run-hooks 'gnus-get-top-new-news-hook)
     (gnus-run-hooks 'gnus-get-new-news-hook)
 
-    ;; Read any slave files.
-    (unless gnus-slave
-      (gnus-master-read-slave-newsrc))
+    ;; Read any child files.
+    (unless gnus-child
+      (gnus-parent-read-child-newsrc))
 
     (gnus-get-unread-articles (gnus-group-default-level arg t)
                               nil one-level)
diff --git a/lisp/gnus/gnus-kill.el b/lisp/gnus/gnus-kill.el
index 5edbaaf201b..a772281d4c3 100644
--- a/lisp/gnus/gnus-kill.el
+++ b/lisp/gnus/gnus-kill.el
@@ -653,7 +653,7 @@ Usage: emacs -batch -l ~/.emacs -l gnus -f gnus-batch-score"
          gnus-options-not-subscribe)
     ;; Eat all arguments.
     (setq command-line-args-left nil)
-    (gnus-slave)
+    (gnus-child)
     ;; Apply kills to specified newsgroups in command line arguments.
     (setq newsrc (cdr gnus-newsrc-alist))
     (while (setq info (pop newsrc))
diff --git a/lisp/gnus/gnus-start.el b/lisp/gnus/gnus-start.el
index 873923e6c57..78e07498de7 100644
--- a/lisp/gnus/gnus-start.el
+++ b/lisp/gnus/gnus-start.el
@@ -730,7 +730,7 @@ the first newsgroup."
   ;; Remove Gnus frames.
   (gnus-kill-gnus-frames))
 
-(defun gnus-no-server-1 (&optional arg slave)
+(defun gnus-no-server-1 (&optional arg child)
   "Read network news.
 If ARG is a positive number, Gnus will use that as the startup
 level.  If ARG is nil, Gnus will be started at level 2
@@ -739,11 +739,11 @@ and not a positive number, Gnus will prompt the user for the name
 of an NNTP server to use.  As opposed to \\[gnus], this command
 will not connect to the local server."
   (let ((val (or arg (1- gnus-level-default-subscribed))))
-    (gnus val t slave)
+    (gnus val t child)
     (make-local-variable 'gnus-group-use-permanent-levels)
     (setq gnus-group-use-permanent-levels val)))
 
-(defun gnus-1 (&optional arg dont-connect slave)
+(defun gnus-1 (&optional arg dont-connect child)
   "Read network news.
 If ARG is non-nil and a positive number, Gnus will use that as the
 startup level.  If ARG is non-nil and not a positive number, Gnus will
@@ -761,7 +761,7 @@ prompt the user for the name of an NNTP server to use."
     (gnus-splash)
     (gnus-run-hooks 'gnus-before-startup-hook)
     (nnheader-init-server-buffer)
-    (setq gnus-slave slave)
+    (setq gnus-child child)
     (gnus-read-init-file)
 
     ;; Add "native" to gnus-predefined-server-alist just to have a
@@ -790,7 +790,7 @@ prompt the user for the name of an NNTP server to use."
                 (gnus-make-newsrc-file gnus-startup-file))
 
           ;; Read the dribble file.
-          (when (or gnus-slave gnus-use-dribble-file)
+          (when (or gnus-child gnus-use-dribble-file)
             (gnus-dribble-read-file))
 
           ;; Do the actual startup.
@@ -1008,11 +1008,11 @@ If LEVEL is non-nil, the news will be set up at level LEVEL."
 
     ;; Possibly eval the dribble file.
     (and init
-         (or gnus-use-dribble-file gnus-slave)
+         (or gnus-use-dribble-file gnus-child)
          (gnus-dribble-eval-file))
 
-    ;; Slave Gnusii should then clear the dribble buffer.
-    (when (and init gnus-slave)
+    ;; Child Gnusii should then clear the dribble buffer.
+    (when (and init gnus-child)
       (gnus-dribble-clear))
 
     (gnus-update-format-specifications)
@@ -1030,7 +1030,7 @@ If LEVEL is non-nil, the news will be set up at level LEVEL."
     ;; Find new newsgroups and treat them.
     (when (and init gnus-check-new-newsgroups (not level)
                (gnus-check-server gnus-select-method)
-               (not gnus-slave)
+               (not gnus-child)
                gnus-plugged)
       (gnus-find-new-newsgroups))
 
@@ -1040,8 +1040,8 @@ If LEVEL is non-nil, the news will be set up at level LEVEL."
                (gnus-server-opened gnus-select-method))
       (gnus-check-bogus-newsgroups))
 
-    ;; Read any slave files.
-    (gnus-master-read-slave-newsrc)
+    ;; Read any child files.
+    (gnus-parent-read-child-newsrc)
 
     ;; Find the number of unread articles in each non-dead group.
     (let ((gnus-read-active-file (and (not level) gnus-read-active-file)))
@@ -2737,15 +2737,15 @@ values from `gnus-newsrc-hashtb', and write a new value of
       (gnus-agent-save-local force))
 
     (save-excursion
-      (if (and (or gnus-use-dribble-file gnus-slave)
+      (if (and (or gnus-use-dribble-file gnus-child)
                (not force)
                (or (not (buffer-live-p gnus-dribble-buffer))
                    (zerop (with-current-buffer gnus-dribble-buffer
                             (buffer-size)))))
           (gnus-message 4 "(No changes need to be saved)")
         (gnus-run-hooks 'gnus-save-newsrc-hook)
-        (if gnus-slave
-            (gnus-slave-save-newsrc)
+        (if gnus-child
+            (gnus-child-save-newsrc)
           ;; Save .newsrc only if the select method is an NNTP method.
           ;; The .newsrc file is for interoperability with other
           ;; newsreaders, so saving non-NNTP groups there doesn't make
@@ -2988,55 +2988,61 @@ SPECIFIC-VARIABLES, or those in `gnus-variable-list'."
 
 
 ;;;
-;;; Slave functions.
+;;; Child functions.
 ;;;
 
-(defvar gnus-slave-mode nil)
+(defvar gnus-child-mode nil)
 
-(defun gnus-slave-mode ()
-  "Minor mode for slave Gnusae."
-  ;; FIXME: gnus-slave-mode appears to never be set (i.e. it'll always be nil):
+(defun gnus-child-mode ()
+  "Minor mode for child Gnusae."
+  ;; FIXME: gnus-child-mode appears to never be set (i.e. it'll always be nil):
   ;; Remove, or fix and use define-minor-mode.
-  (add-minor-mode 'gnus-slave-mode " Slave" (make-sparse-keymap))
-  (gnus-run-hooks 'gnus-slave-mode-hook))
+  (add-minor-mode 'gnus-child-mode " Child" (make-sparse-keymap))
+  (gnus-run-hooks 'gnus-child-mode-hook))
 
-(defun gnus-slave-save-newsrc ()
+(define-obsolete-function-alias 'gnus-slave-mode #'gnus-child-mode "28.1")
+(define-obsolete-variable-alias 'gnus-slave-mode-hook 'gnus-child-mode-hook
+  "28.1")
+
+(defun gnus-child-save-newsrc ()
   (with-current-buffer gnus-dribble-buffer
     (with-file-modes (or (ignore-errors
                            (file-modes
                             (concat gnus-current-startup-file ".eld")))
                          (default-file-modes))
-      (let ((slave-name
-             (make-temp-file (concat gnus-current-startup-file "-slave-"))))
+      (let ((child-name
+             (make-temp-file (concat gnus-current-startup-file "-child-"))))
         (let ((coding-system-for-write gnus-ding-file-coding-system))
-          (gnus-write-buffer slave-name))))))
+          (gnus-write-buffer child-name))))))
 
-(defun gnus-master-read-slave-newsrc ()
-  (let ((slave-files
+(defun gnus-parent-read-child-newsrc ()
+  (let ((child-files
          (directory-files
           (file-name-directory gnus-current-startup-file)
           t (concat
              "^" (regexp-quote
-                  (concat
-                   (file-name-nondirectory gnus-current-startup-file)
-                   "-slave-")))
+                  (file-name-nondirectory gnus-current-startup-file))
+             ;; When the obsolete variables like
+             ;; `gnus-slave-mode-hook' etc are removed, the "slave"
+             ;; bit of this regexp should also be removed.
+             "\\(-child-\\|-slave-\\)")
           t))
         file)
-    (if (not slave-files)
-        ()                              ; There are no slave files to read.
-      (gnus-message 7 "Reading slave newsrcs...")
-      (with-current-buffer (gnus-get-buffer-create " *gnus slave*")
-        (setq slave-files
+    (if (not child-files)
+        ()                              ; There are no child files to read.
+      (gnus-message 7 "Reading child newsrcs...")
+      (with-current-buffer (gnus-get-buffer-create " *gnus child*")
+        (setq child-files
               (sort (mapcar (lambda (file)
                               (list (file-attribute-modification-time
                                      (file-attributes file))
                                     file))
-                            slave-files)
+                            child-files)
                     (lambda (f1 f2)
                       (time-less-p (car f1) (car f2)))))
-        (while slave-files
+        (while child-files
           (erase-buffer)
-          (setq file (nth 1 (car slave-files)))
+          (setq file (nth 1 (car child-files)))
           (nnheader-insert-file-contents file)
           (when (condition-case ()
                     (progn
@@ -3045,12 +3051,12 @@ SPECIFIC-VARIABLES, or those in `gnus-variable-list'."
                   (error
                    (gnus-error 3.2 "Possible error in %s" file)
                    nil))
-            (unless gnus-slave          ; Slaves shouldn't delete these files.
+            (unless gnus-child          ; Children shouldn't delete these files.
               (ignore-errors
                 (delete-file file))))
-          (setq slave-files (cdr slave-files))))
+          (setq child-files (cdr child-files))))
       (gnus-dribble-touch)
-      (gnus-message 7 "Reading slave newsrcs...done"))))
+      (gnus-message 7 "Reading child newsrcs...done"))))
 
 
 ;;;
diff --git a/lisp/gnus/gnus.el b/lisp/gnus/gnus.el
index caeab7f55af..f40ce0c7926 100644
--- a/lisp/gnus/gnus.el
+++ b/lisp/gnus/gnus.el
@@ -2226,8 +2226,8 @@ Disabling the agent may result in noticeable loss of performance."
   :group 'gnus-start
   :type '(choice (function-item gnus)
                  (function-item gnus-no-server)
-                 (function-item gnus-slave)
-                 (function-item gnus-slave-no-server)))
+                 (function-item gnus-child)
+                 (function-item gnus-child-no-server)))
 
 (declare-function gnus-group-get-new-news "gnus-group")
 
@@ -2238,8 +2238,8 @@ Disabling the agent may result in noticeable loss of performance."
   :type '(choice (function-item gnus)
                  (function-item gnus-group-get-new-news)
                  (function-item gnus-no-server)
-                 (function-item gnus-slave)
-                 (function-item gnus-slave-no-server)))
+                 (function-item gnus-child)
+                 (function-item gnus-child-no-server)))
 
 (defcustom gnus-other-frame-parameters nil
   "Frame parameters used by `gnus-other-frame' to create a Gnus frame."
@@ -2417,8 +2417,8 @@ such as a mark that says whether an article is stored in the cache
 (defvar gnus-article-buffer "*Article*")
 (defvar gnus-server-buffer "*Server*")
 
-(defvar gnus-slave nil
-  "Whether this Gnus is a slave or not.")
+(defvar gnus-child nil
+  "Whether this Gnus is a child or not.")
 
 (defvar gnus-batch-mode nil
   "Whether this Gnus is running in batch mode or not.")
@@ -4034,13 +4034,17 @@ Allow completion over sensible values."
 ;;; User-level commands.
 
 ;;;###autoload
-(defun gnus-slave-no-server (&optional arg)
-  "Read network news as a slave, without connecting to the local server."
+(defun gnus-child-no-server (&optional arg)
+  "Read network news as a child, without connecting to the local server."
   (interactive "P")
   (gnus-no-server arg t))
 
 ;;;###autoload
-(defun gnus-no-server (&optional arg slave)
+(define-obsolete-function-alias 'gnus-slave-no-server #'gnus-child-no-server
+  "28.1")
+
+;;;###autoload
+(defun gnus-no-server (&optional arg child)
   "Read network news.
 If ARG is a positive number, Gnus will use that as the startup level.
 If ARG is nil, Gnus will be started at level 2.  If ARG is non-nil
@@ -4049,13 +4053,17 @@ an NNTP server to use.
 As opposed to `gnus', this command will not connect to the local
 server."
   (interactive "P")
-  (gnus-no-server-1 arg slave))
+  (gnus-no-server-1 arg child))
 
 ;;;###autoload
-(defun gnus-slave (&optional arg)
-  "Read news as a slave."
+(defun gnus-child (&optional arg)
+  "Read news as a child."
   (interactive "P")
-  (gnus arg nil 'slave))
+  (gnus arg nil 'child))
+
+;;;###autoload
+(define-obsolete-function-alias 'gnus-slave #'gnus-child "28.1")
+
 
 (defun gnus-delete-gnus-frame ()
   "Delete gnus frame unless it is the only one.
@@ -4116,7 +4124,7 @@ current display is used."
   (add-hook 'gnus-suspend-gnus-hook #'gnus-delete-gnus-frame)))))
 
 ;;;###autoload
-(defun gnus (&optional arg dont-connect slave)
+(defun gnus (&optional arg dont-connect child)
   "Read network news.
 If ARG is non-nil and a positive number, Gnus will use that as the
 startup level.  If ARG is non-nil and not a positive number, Gnus will
@@ -4130,7 +4138,7 @@ prompt the user for the name of an NNTP server to use."
     (message "You should byte-compile Gnus")
     (sit-for 2))
   (let ((gnus-action-message-log (list nil)))
-    (gnus-1 arg dont-connect slave)
+    (gnus-1 arg dont-connect child)
     (gnus-final-warning)))
 
 (declare-function debbugs-gnu "ext:debbugs-gnu"