Rename '--new-daemon' to 'fg-daemon' and '--old-daemon' to '--bg-daemon'

* doc/emacs/cmdargs.texi (Initial Options):
* doc/lispref/os.texi (Startup Summary):
* etc/NEWS:
* etc/emacs.service:
* src/emacs.c (main):
* src/lisp.h: Rename '--new-daemon' to 'fg-daemon' and '--old-daemon' to
'--bg-daemon'.

doc/emacs/cmdargs.texi

@@ -336,16 +336,16 @@ setting @code{inhibit-x-resources} to @code{t} (@pxref{Resources}).
 @opindex -daemon
 @itemx --daemon[=@var{name}]
 @opindex --daemon
-@itemx --old-daemon[=@var{name}]
-@itemx --new-daemon[=@var{name}]
+@itemx --bg-daemon[=@var{name}]
+@itemx --fg-daemon[=@var{name}]
 Start Emacs as a daemon---after Emacs starts up, it starts the Emacs
 server without opening any frames.
 (Optionally, you can specify an explicit @var{name} for the server.)
 You can then use the @command{emacsclient} command to connect to Emacs
 for editing.  @xref{Emacs Server}, for information about using Emacs
-as a daemon.  An ``old-style'' daemon disconnects from the terminal
+as a daemon.  A ``background'' daemon disconnects from the terminal
 and runs in the background (@samp{--daemon} is an alias for
-@samp{--old-daemon}).
+@samp{--bg-daemon}).
 
 @item --no-desktop
 @opindex --no-desktop

doc/lispref/os.texi

@@ -337,10 +337,10 @@ Do not display a splash screen.
 Run without an interactive terminal.  @xref{Batch Mode}.
 
 @item --daemon
-@itemx --old-daemon
-@itemx --new-daemon
+@itemx --bg-daemon
+@itemx --fg-daemon
 Do not initialize any display; just start a server.
-(An ``old-style'' daemon automatically runs in the background.)
+(A ``background'' daemon automatically runs in the background.)
 
 @item --no-init-file
 @itemx -q

etc/NEWS

@@ -78,10 +78,11 @@ affected by this, as SGI stopped supporting IRIX in December 2013.
 
 * Startup Changes in Emacs 26.1
 
-** New option '--new-daemon'.  This is the same as '--daemon', except
++++
+** New option '--fg-daemon'.  This is the same as '--daemon', except
 it runs in the foreground and does not fork.  This is intended for
 modern init systems such as systemd, which manage many of the traditional
-aspects of daemon behavior themselves.  '--old-daemon' is now an alias
+aspects of daemon behavior themselves.  '--bg-daemon' is now an alias
 for '--daemon'.
 
 +++

etc/emacs.service

@@ -8,7 +8,7 @@ Documentation=info:emacs man:emacs(1) https://gnu.org/software/emacs/
 
 [Service]
 Type=simple
-ExecStart=emacs --new-daemon
+ExecStart=emacs --fg-daemon
 ExecStop=emacsclient --eval "(kill-emacs)"
 Environment=SSH_AUTH_SOCK=%t/keyring/ssh
 Restart=on-failure

src/emacs.c

@@ -219,8 +219,8 @@ Initialization options:\n\
     "\
 --batch                     do not do interactive display; implies -q\n\
 --chdir DIR                 change to directory DIR\n\
---daemon, --old-daemon[=NAME] start a (named) server in the background\n\
---new-daemon[=NAME]         start a (named) server in the foreground\n\
+--daemon, --bg-daemon[=NAME] start a (named) server in the background\n\
+--fg-daemon[=NAME]          start a (named) server in the foreground\n\
 --debug-init                enable Emacs Lisp debugger for init file\n\
 --display, -d DISPLAY       use X server DISPLAY\n\
 ",
@@ -991,15 +991,15 @@ main (int argc, char **argv)
 
   int sockfd = -1;
 
-  if (argmatch (argv, argc, "-new-daemon", "--new-daemon", 10, NULL, &skip_args)
-      || argmatch (argv, argc, "-new-daemon", "--new-daemon", 10, &dname_arg, &skip_args))
+  if (argmatch (argv, argc, "-fg-daemon", "--fg-daemon", 10, NULL, &skip_args)
+      || argmatch (argv, argc, "-fg-daemon", "--fg-daemon", 10, &dname_arg, &skip_args))
     {
       daemon_type = 1;           /* foreground */
     }
   else if (argmatch (argv, argc, "-daemon", "--daemon", 5, NULL, &skip_args)
       || argmatch (argv, argc, "-daemon", "--daemon", 5, &dname_arg, &skip_args)
-      || argmatch (argv, argc, "-old-daemon", "--old-daemon", 10, NULL, &skip_args)
-      || argmatch (argv, argc, "-old-daemon", "--old-daemon", 10, &dname_arg, &skip_args))
+      || argmatch (argv, argc, "-bg-daemon", "--bg-daemon", 10, NULL, &skip_args)
+      || argmatch (argv, argc, "-bg-daemon", "--bg-daemon", 10, &dname_arg, &skip_args))
     {
       daemon_type = 2;          /* background */
     }
@@ -1114,7 +1114,7 @@ Using an Emacs configured with --with-x-toolkit=lucid does not have this problem
                 char fdStr[80];
                 int fdStrlen =
                   snprintf (fdStr, sizeof fdStr,
-                            "--old-daemon=\n%d,%d\n%s", daemon_pipe[0],
+                            "--bg-daemon=\n%d,%d\n%s", daemon_pipe[0],
                             daemon_pipe[1], dname_arg ? dname_arg : "");
 
                 if (! (0 <= fdStrlen && fdStrlen < sizeof fdStr))
@@ -1711,8 +1711,8 @@ static const struct standard_args standard_args[] =
   { "-batch", "--batch", 100, 0 },
   { "-script", "--script", 100, 1 },
   { "-daemon", "--daemon", 99, 0 },
-  { "-old-daemon", "--old-daemon", 99, 0 },
-  { "-new-daemon", "--new-daemon", 99, 0 },
+  { "-bg-daemon", "--bg-daemon", 99, 0 },
+  { "-fg-daemon", "--fg-daemon", 99, 0 },
   { "-help", "--help", 90, 0 },
   { "-nl", "--no-loadup", 70, 0 },
   { "-nsl", "--no-site-lisp", 65, 0 },

src/lisp.h

@@ -4167,7 +4167,7 @@ extern bool no_site_lisp;
 extern bool build_details;
 
 #ifndef WINDOWSNT
-/* 0 not a daemon, 1 new-style (foreground), 2 old-style (background).  */
+/* 0 not a daemon, 1 foreground daemon, 2 background daemon.  */
 extern int daemon_type;
 #define IS_DAEMON (daemon_type != 0)
 #define DAEMON_RUNNING (daemon_type >= 0)