patch 9.2.0512: clientserver uses binary protocol

Problem:  clientserver feature uses binary protocol and is hard
          to understand
Solution: Rewrite the code based on channels and JSON messages
          (Foxe Chen).

closes: #19782

Signed-off-by: Foxe Chen <chen.foxe@gmail.com>
Signed-off-by: Christian Brabandt <cb@256bit.org>

Filelist

@@ -145,6 +145,7 @@ SRC_ALL =	\
 		src/session.c \
 		src/sha256.c \
 		src/sign.c \
+		src/socketserver.c \
 		src/sound.c \
 		src/spell.c \
 		src/spell.h \
@@ -344,6 +345,7 @@ SRC_ALL =	\
 		src/proto/session.pro \
 		src/proto/sha256.pro \
 		src/proto/sign.pro \
+		src/proto/socketserver.pro \
 		src/proto/sound.pro \
 		src/proto/spell.pro \
 		src/proto/spellfile.pro \

runtime/doc/remote.txt

@@ -79,9 +79,10 @@ The following command line arguments are available:
 								*--clientserver*
    --clientserver {method}	Use the specified method {method} as the
 				backend for clientserver functionality.  Can
-				either be "socket" or "x11".
+				either be "socket", "x11", or "mswin".
 				{only available when compiled with both |+X11|
-				and |+socketserver| features}
+				and |+socketserver| features, or
+				|+socketserver| on MS-Windows}
 
 
 Examples ~
@@ -220,12 +221,16 @@ When using gvim, the --remote-wait only works properly this way: >
 <
 ==============================================================================
 4. Socket server specific items			    *socketserver-clientserver*
-				    *E1563* *E1564* *E1565* *E1566* *E1567*
+						    *E1564* *E1565* *E1566*
 
-The communication between client and server is done using Unix domain sockets.
-These sockets are either placed in these directories in the following order of
+NOTE: Vim version before patch 9.2.511 use a different socketserver backend
+which is incompatible with the new one, which is based on channels and JSON.
+
+The communication between client and server is done using channels internally.
+When using the traditional/generic clientserver naming (only available on
+Unix), sockets are placed in these directories in the following order of
 availability:
-    1. "$XDG_RUTIME_DIR/vim" if $XDG_RUNTIME_DIR is set in the environment.
+    1. "$XDG_RUNTIME_DIR/vim" if $XDG_RUNTIME_DIR is set in the environment.
     2. "$TMPDIR/vim-[uid]", where "[uid]" is the uid of the user.  This
        directory will have the access permissions set to 700 so only the user
        can read or write from/to it.  If $TMPDIR is not set, "/tmp" is used.
@@ -237,45 +242,55 @@ absolute or relative path.  If the server id starts with either a "/"
 Otherwise the server id will be the filename of the socket which will be
 placed in the above common directories.  Note that a server id/name can only
 contain slashes "/" if it is taken as a path, so names such as "abc/dir" will
-be invalid.
+be invalid.  This feature is only available on Unix.
 
-Socket server functionality is available in both GTK GUI and terminal versions
-of Vim.  Unless Vim is compiled with |+autoservername| feature, the socket
-server will have to started explicitly, just like X11, even in the GUI.
+						    *socketserver-address*
+In addition, the socketserver can also be created as a |channel-address|. To
+do this, prefix the address with "channel:" (which will be ignored).  This is
+available on both Unix and MS-Windows, and is the only available naming for the
+socketserver backend on Windows.  However, note that |ch_listen()|
+restrictions apply, meaning only port numbers can be used for TCP sockets.
+
+If the name is prefixed with "name:", then the legacy servername behaviour is
+used, so "name:VIM" is the same as "VIM".
+
+Unless Vim is compiled with |+autoservername| feature, the socket server will
+have to started explicitly, similar to X11. This is unless a X11 GUI Vim is
+being used.
 
 If Vim crashes or does not exit cleanly, the socket server will not remove the
 socket file and it will be left around.  This is generally not a problem,
 because if a socket name is taken, Vim checks if the socket in its place is
 dead (not attached to any process), and can replace it instead of finding a
-new name.
-
-To send commands to a Vim socket server from another application, read the
-source file src/os_unix.c, there is detailed description of the protocol used.
+new name.  This is only relevant for Unix.
 
 						    *socketserver-differences*
-Most of the functionality is the same as X11, however unlike X11, where the
-client does not need to be a server in order to communicate with another
-server, the socket server requires the server to be running even as a client.
-The exception is |serverlist()| or the |--serverlist| argument, which does not
-require the server to be running.
+Most of the functionality is the same as the other clientserver backends.
 
-Additionally, the server id or client id will not be a number like X11 or
+However, the server id or client id will not be a number like X11 or
 MS-Windows (shown in hex representation), instead it is the absolute path to
-the socket.  This can be seen via the |v:servername| variable.
+the socket.  This can be seen via the |v:servername| variable.  If the name is
+a channel address, then it will be the address with the "a/" prefix as well.
 
-The |--serverlist| argument will act just like X11, however it only checks the
-given common directories above.  If a custom path is used for a socket, it
-will not be detected, such as a path either not in $XDG_RUNTIME_DIR or
-<$TMPDIR or /tmp>/vim of the |--serverlist| Vim process.
+Note when using |--remote-wait|, the client id will look like "t/<some
+number>". This naming is specifically for this command, and attempting to use
+it as an address will fail.
 
-If you have both |+socketserver| and |+X11| compiled, you will need to add
-|--clientserver| set to "socket" in combination with |--serverlist| to list
-the available servers.  You cannot list both types of backends in one command.
+If on Unix, the |--serverlist| argument will act just like X11, however it
+only checks the given common directories above.  If a custom path is used for
+a socket, it will not be detected, such as a path either not in
+$XDG_RUNTIME_DIR or <$TMPDIR or /tmp>/vim of the |--serverlist| Vim process.
+If on MS-Windows, then the |--serverlist| argument will output nothing.
+
+The |+socketserver| feature is automatically enabled when on Unix or
+MS-Windows, and the |+channel| feature is enabled
 
 						    *socketserver-x11*
-If Vim is compiled with both |+X11| and |+socketserver|, then deciding which
-backend to use is done at startup time, via the |--clientserver| argument.  By
-default if it is not specified, then X11 will be used.  A Vim instance using a
-socket server cannot communicate with one using X11.
+If Vim is compiled with |+socketserver| and another clientserver backend, then
+deciding which backend to use is done at startup time, via the
+|--clientserver| argument.  By default if it is not specified, then the native
+backend (X11 or MS-Window messages) will be used, if available.  A Vim
+instance using a socket server cannot communicate with one using another
+clientserver backend.
 
  vim:tw=78:sw=4:ts=8:noet:ft=help:norl:

runtime/doc/tags

@@ -4762,11 +4762,9 @@ E156	sign.txt	/*E156*
 E1560	vim9.txt	/*E1560*
 E1561	vim9.txt	/*E1561*
 E1562	options.txt	/*E1562*
-E1563	remote.txt	/*E1563*
 E1564	remote.txt	/*E1564*
 E1565	remote.txt	/*E1565*
 E1566	remote.txt	/*E1566*
-E1567	remote.txt	/*E1567*
 E1568	options.txt	/*E1568*
 E1569	builtin.txt	/*E1569*
 E157	sign.txt	/*E157*
@@ -10377,6 +10375,7 @@ slow-fast-terminal	term.txt	/*slow-fast-terminal*
 slow-start	starting.txt	/*slow-start*
 slow-terminal	term.txt	/*slow-terminal*
 socket-interface	channel.txt	/*socket-interface*
+socketserver-address	remote.txt	/*socketserver-address*
 socketserver-clientserver	remote.txt	/*socketserver-clientserver*
 socketserver-differences	remote.txt	/*socketserver-differences*
 socketserver-name	remote.txt	/*socketserver-name*

runtime/doc/version9.txt

@@ -1,4 +1,4 @@
-*version9.txt*	For Vim version 9.2.  Last change: 2026 May 19
+*version9.txt*	For Vim version 9.2.  Last change: 2026 May 22
 
 
 		  VIM REFERENCE MANUAL	  by Bram Moolenaar
@@ -52665,6 +52665,7 @@ Changed ~
   if needed, see |wayland-primary-selection| for an example.
 - On Unix, filename completion for single-file Ex commands now treats embedded
   whitespace as part of the filename, like on other platforms.
+- Rewrite the clientserver socketserver backend to use channels and JSON.
 
 
 							*added-9.3*

runtime/doc/vim.1

@@ -504,9 +504,10 @@ socketserver backend is being used, if the name starts with "/", "./", or "../",
 it is taken as either an absolute, relative or relative path to the socket.
 .TP
 \-\-clientserver {backend}
-Use {backend} as the backend for clientserver functionality, either "socket" or
-"x11" respectively.  Only available when compiled with both socketserver and X11
-features present
+Use {backend} as the backend for clientserver functionality, either "socket",
+"x11", or "mswin" respectively.  Only available when compiled with both
+socketserver and X11 features present, or if compiled with socketserver on
+MS-Windows.
 .TP
 \-\-socketid {id}
 GTK GUI only: Use the GtkPlug mechanism to run gVim in another window.

runtime/doc/vim.man

@@ -385,9 +385,10 @@ OPTIONS
 
        --clientserver {backend}
                    Use {backend} as the backend for  clientserver  functional‐
-                   ity, either "socket" or "x11" respectively.  Only available
-                   when  compiled  with  both  socketserver  and  X11 features
-                   present
+                   ity, either "socket", "x11", or "mswin" respectively.  Only
+                   available when compiled with both socketserver and X11 fea‐
+                   tures  present, or if compiled with socketserver on MS-Win‐
+                   dows.
 
        --socketid {id}
                    GTK GUI only: Use the GtkPlug mechanism to run gVim in  an‐

src/Make_cyg_ming.mak

@@ -877,6 +877,7 @@ OBJ = \
 	$(OUTDIR)/session.o \
 	$(OUTDIR)/sha256.o \
 	$(OUTDIR)/sign.o \
+	$(OUTDIR)/socketserver.o \
 	$(OUTDIR)/spell.o \
 	$(OUTDIR)/spellfile.o \
 	$(OUTDIR)/spellsuggest.o \

src/Make_mvc.mak

@@ -772,6 +772,7 @@ OBJ = \
 	$(OUTDIR)\session.obj \
 	$(OUTDIR)\sha256.obj \
 	$(OUTDIR)\sign.obj \
+	$(OUTDIR)\socketserver.obj \
 	$(OUTDIR)\spell.obj \
 	$(OUTDIR)\spellfile.obj \
 	$(OUTDIR)\spellsuggest.obj \
@@ -1767,6 +1768,8 @@ $(OUTDIR)/sha256.obj: $(OUTDIR) sha256.c $(INCL)
 
 $(OUTDIR)/sign.obj: $(OUTDIR) sign.c $(INCL)
 
+$(OUTDIR)/socketserver.obj: $(OUTDIR) socketserver.c $(INCL)
+
 $(OUTDIR)/spell.obj: $(OUTDIR) spell.c $(INCL)
 
 $(OUTDIR)/spellfile.obj: $(OUTDIR) spellfile.c $(INCL)
@@ -2017,6 +2020,7 @@ proto.h: \
 	proto/session.pro \
 	proto/sha256.pro \
 	proto/sign.pro \
+	proto/socketserver.pro \
 	proto/spell.pro \
 	proto/spellfile.pro \
 	proto/spellsuggest.pro \

src/Makefile

@@ -1571,6 +1571,7 @@ BASIC_SRC = \
 	session.c \
 	sha256.c \
 	sign.c \
+	socketserver.c \
 	sound.c \
 	spell.c \
 	spellfile.c \
@@ -1749,6 +1750,7 @@ OBJ_COMMON = \
 	objects/session.o \
 	objects/sha256.o \
 	objects/sign.o \
+	objects/socketserver.o \
 	objects/sound.o \
 	objects/spell.o \
 	objects/spellfile.o \
@@ -3592,6 +3594,9 @@ objects/sha256.o: sha256.c
 objects/sign.o: sign.c
 	$(CCC) -o $@ sign.c
 
+objects/socketserver.o: socketserver.c
+	$(CCC) -o $@ socketserver.c
+
 objects/sound.o: sound.c
 	$(CCC) -o $@ sound.c
 
@@ -4267,6 +4272,11 @@ objects/sign.o: auto/osdef.h sign.c vim.h protodef.h auto/config.h feature.h os_
  structs.h regexp.h gui.h libvterm/include/vterm.h \
  libvterm/include/vterm_keycodes.h alloc.h ex_cmds.h spell.h proto.h \
  globals.h errors.h
+objects/socketserver.o: socketserver.c vim.h protodef.h auto/config.h feature.h \
+ os_unix.h auto/osdef.h ascii.h keymap.h termdefs.h macros.h option.h \
+ beval.h structs.h regexp.h gui.h libvterm/include/vterm.h \
+ libvterm/include/vterm_keycodes.h xdiff/xdiff.h xdiff/../vim.h alloc.h \
+ ex_cmds.h spell.h proto.h globals.h errors.h
 objects/sound.o: auto/osdef.h sound.c vim.h protodef.h auto/config.h feature.h os_unix.h \
  ascii.h keymap.h termdefs.h macros.h option.h beval.h \
  structs.h regexp.h gui.h libvterm/include/vterm.h \
@@ -4793,6 +4803,7 @@ proto/search.pro: search.c
 proto/session.pro: session.c
 proto/sha256.pro: sha256.c
 proto/sign.pro: sign.c
+proto/socketserver.pro: socketserver.c
 proto/sound.pro: sound.c
 proto/spell.pro: spell.c
 proto/spellfile.pro: spellfile.c

src/auto/configure

@@ -850,7 +850,6 @@ enable_netbeans
 enable_channel
 enable_terminal
 enable_autoservername
-enable_socketserver
 enable_multibyte
 enable_rightleft
 enable_arabic
@@ -1532,7 +1531,6 @@ Optional Features:
   --disable-channel       Disable process communication support.
   --enable-terminal       Enable terminal emulation support.
   --enable-autoservername Automatically define servername at vim startup.
-  --enable-socketserver Use sockets for clientserver communication.
   --enable-multibyte      Include multibyte editing support.
   --disable-rightleft     Do not include Right-to-Left language support.
   --disable-arabic        Do not include Arabic language support.
@@ -9077,36 +9075,6 @@ if test "$enable_autoservername" = "yes"; then
 
 fi
 
-{ printf "%s\n" "$as_me:${as_lineno-$LINENO}: checking --enable-socketserver argument" >&5
-printf %s "checking --enable-socketserver argument... " >&6; }
-# Check whether --enable-socketserver was given.
-if test ${enable_socketserver+y}
-then :
-  enableval=$enable_socketserver; enable_socketserver=$enableval
-else case e in #(
-  e) if test "x$features" = xtiny
-then :
-  enable_socketserver=no_msg
-			 { printf "%s\n" "$as_me:${as_lineno-$LINENO}: result: cannot use socketserver with tiny features" >&5
-printf "%s\n" "cannot use socketserver with tiny features" >&6; }
-else case e in #(
-  e) enable_socketserver=yes ;;
-esac
-fi ;;
-esac
-fi
-
-
-if test "$enable_socketserver" = "yes"; then
-  printf "%s\n" "#define WANT_SOCKETSERVER 1" >>confdefs.h
-
-  { printf "%s\n" "$as_me:${as_lineno-$LINENO}: result: yes" >&5
-printf "%s\n" "yes" >&6; }
-elif test "$enable_socketserver" = "no"; then
-  { printf "%s\n" "$as_me:${as_lineno-$LINENO}: result: no" >&5
-printf "%s\n" "no" >&6; }
-fi
-
 { printf "%s\n" "$as_me:${as_lineno-$LINENO}: checking --enable-multibyte argument" >&5
 printf %s "checking --enable-multibyte argument... " >&6; }
 # Check whether --enable-multibyte was given.

src/channel.c

@@ -820,7 +820,7 @@ channel_connect(
  * Returns the channel for success.
  * Returns NULL for failure.
  */
-    static channel_T *
+    channel_T *
 channel_open_unix(
 	const char *path,
 	void (*nb_close_cb)(void))
@@ -1290,6 +1290,46 @@ channel_set_options(channel_T *channel, jobopt_T *opt)
     channel->ch_part[PART_IN].ch_io = opt->jo_io[PART_IN];
 }
 
+/*
+ * Parse the address for socketserver and store port in "port", or the path in
+ * "unix_path" if it is a unix domain socket. Returns OK on success and FAIL on
+ * failure.
+ */
+    int
+channel_parse_socketserver_address(
+	char_u	*address,
+	int	*port,
+	char_u	**unix_path,
+	bool	quiet)
+{
+    char    *rest;
+    long    val;
+
+    if (*address == NUL)
+	goto fail;
+
+    if (!STRNCMP(address, "unix:", 5))
+    {
+	*unix_path = vim_strsave(address + 5);
+	return OK;
+    }
+
+    val = strtol((char *)(address), &rest, 10);
+    if (val < 0 || val >= 65536 || *rest != NUL)
+    {
+	if (!quiet)
+	    semsg(_(e_invalid_argument_str), address);
+	return FAIL;
+    }
+    *port = (int)val;
+
+    return OK;
+fail:
+    if (!quiet)
+	semsg(_(e_invalid_argument_str), address);
+    return FAIL;
+}
+
 /*
  * Implements ch_open().
  */
@@ -1449,7 +1489,7 @@ channel_listen_func(typval_T *argvars)
     }
 
     if (is_unix)
-	channel = channel_listen_unix((char *)arg, NULL);
+	channel = channel_listen_unix((char *)arg, NULL, true);
     else
 	channel = channel_listen(port, NULL);
     if (channel != NULL)
@@ -1571,13 +1611,15 @@ channel_listen(
 
 /*
  * Listen to a Unix domain socket channel.
+ * If "replace" is true, then unlink the path first beforehand.
  * Returns the channel for success.
  * Returns NULL for failure.
  */
     channel_T *
 channel_listen_unix(
 	char *path,
-	void (*nb_close_cb)(void))
+	void (*nb_close_cb)(void),
+	bool replace)
 {
     int			sd = -1;
     struct sockaddr_un	server;
@@ -1619,8 +1661,9 @@ channel_listen_unix(
 	return NULL;
     }
 
-    // Unlink the socket in case it already exists
-    unlink(server.sun_path);
+    if (replace)
+	// Unlink the socket in case it already exists
+	unlink(server.sun_path);
 
     // Bind the socket to the path
     server_len = offsetof(struct sockaddr_un, sun_path) + path_len + 1;
@@ -1983,7 +2026,7 @@ channel_buffer_free(buf_T *buf)
 /*
  * Write any lines waiting to be written to "channel".
  */
-    static void
+    void
 channel_write_input(channel_T *channel)
 {
     chanpart_T	*in_part = &channel->ch_part[PART_IN];
@@ -2364,7 +2407,7 @@ channel_save(channel_T *channel, ch_part_T part, char_u *buf, int len,
  * Try to fill the buffer of "reader".
  * Returns FALSE when nothing was added.
  */
-    static int
+    int
 channel_fill(js_read_T *reader)
 {
     channel_T	*channel = (channel_T *)reader->js_cookie;
@@ -2484,11 +2527,12 @@ channel_process_lspdap_http_hdr(js_read_T *reader)
 
 /*
  * Use the read buffer of "channel"/"part" and parse a JSON message that is
- * complete.  The messages are added to the queue.
+ * complete.  The messages are added to the queue. If "socketserver" is true,
+ * then ignore the channel mode.
  * Return TRUE if there is more to read.
  */
-    static int
-channel_parse_json(channel_T *channel, ch_part_T part)
+    int
+channel_parse_json(channel_T *channel, ch_part_T part, bool socketserver)
 {
     js_read_T	reader;
     typval_T	listtv;
@@ -2507,8 +2551,8 @@ channel_parse_json(channel_T *channel, ch_part_T part)
     reader.js_cookie = channel;
     reader.js_cookie_arg = part;
 
-    if (chanpart->ch_mode == CH_MODE_LSP
-	    || chanpart->ch_mode == CH_MODE_DAP)
+    if (!socketserver && (chanpart->ch_mode == CH_MODE_LSP
+	    || chanpart->ch_mode == CH_MODE_DAP))
 	status = channel_process_lspdap_http_hdr(&reader);
 
     // When a message is incomplete we wait for a short while for more to
@@ -2526,14 +2570,16 @@ channel_parse_json(channel_T *channel, ch_part_T part)
     {
 	// Only accept the response when it is a list with at least two
 	// items.
-	if ((chanpart->ch_mode == CH_MODE_LSP || chanpart->ch_mode == CH_MODE_DAP)
+	if (!socketserver && (chanpart->ch_mode == CH_MODE_LSP
+		    || chanpart->ch_mode == CH_MODE_DAP)
 		&& listtv.v_type != VAR_DICT)
 	{
 	    ch_error(channel, "Did not receive a LSP dict, discarding");
 	    clear_tv(&listtv);
 	}
-	else if (chanpart->ch_mode != CH_MODE_LSP && chanpart->ch_mode != CH_MODE_DAP
-	      && (listtv.v_type != VAR_LIST || listtv.vval.v_list->lv_len < 2))
+	else if (!socketserver && chanpart->ch_mode != CH_MODE_LSP
+		&& chanpart->ch_mode != CH_MODE_DAP
+		&& (listtv.v_type != VAR_LIST || listtv.vval.v_list->lv_len < 2))
 	{
 	    if (listtv.v_type != VAR_LIST)
 		ch_error(channel, "Did not receive a list, discarding");
@@ -2668,7 +2714,7 @@ remove_cb_node(cbq_T *head, cbq_T *node)
  * Remove "node" from the queue that it is in and free it.
  * Caller should have freed or used node->jq_value.
  */
-    static void
+    void
 remove_json_node(jsonq_T *head, jsonq_T *node)
 {
     if (node->jq_prev == NULL)
@@ -3227,8 +3273,12 @@ may_invoke_callback(channel_T *channel, ch_part_T part)
     int		called_otc;		// one time callbackup
     int		raw_len = 0;
 
-    if (channel->ch_nb_close_cb != NULL)
-	// this channel is handled elsewhere (netbeans)
+    if (channel->ch_nb_close_cb != NULL
+#ifdef FEAT_SOCKETSERVER
+	    || channel->ch_socketserver
+#endif
+	    )
+	// this channel is handled elsewhere (netbeans or socketserver)
 	return FALSE;
 
     // Use a message-specific callback, part callback or channel callback
@@ -3267,7 +3317,7 @@ may_invoke_callback(channel_T *channel, ch_part_T part)
 		(void)channel_collapse(channel, part, FALSE);
 
 	    // Parse readahead, return when there is still no message.
-	    channel_parse_json(channel, part);
+	    channel_parse_json(channel, part, false);
 	    if (channel_get_json(channel, part, -1, FALSE, &listtv) == FAIL)
 		return FALSE;
 	}
@@ -3595,7 +3645,7 @@ channel_readahead_pointer(channel_T *channel, ch_part_T part)
 	if (head->jq_next == NULL)
 	    // Parse json from readahead, there might be a complete message to
 	    // process.
-	    channel_parse_json(channel, part);
+	    channel_parse_json(channel, part, false);
 
 	return head->jq_next;
     }
@@ -3842,6 +3892,11 @@ channel_close(channel_T *channel, int invoke_close_cb)
     }
 
     channel->ch_nb_close_cb = NULL;
+#ifdef FEAT_SOCKETSERVER
+    channel->ch_socketserver = false;
+    channel->ch_ss_accept_cb = NULL;
+    channel->ch_ss_close_cb = NULL;
+#endif
 
 #ifdef FEAT_TERMINAL
     term_channel_closed(channel);
@@ -4181,6 +4236,10 @@ channel_close_now(channel_T *channel)
     ch_log(channel, "Closing channel because all readable fds are closed");
     if (channel->ch_nb_close_cb != NULL)
 	(*channel->ch_nb_close_cb)();
+#ifdef FEAT_SOCKETSERVER
+    if (channel->ch_ss_close_cb != NULL)
+	channel->ch_ss_close_cb(channel);
+#endif
     channel_close(channel, TRUE);
 }
 
@@ -4252,6 +4311,14 @@ channel_read(channel_T *channel, ch_part_T part, char *func)
 	    channel_gui_register_one(newchannel, PART_SOCK);
 #endif
 
+#ifdef FEAT_SOCKETSERVER
+	    if (channel->ch_ss_accept_cb != NULL)
+	    {
+		channel->ch_ss_accept_cb(newchannel);
+		return;
+	    }
+#endif
+
 	    if (client.ss_family == AF_INET)
 	    {
 #ifdef HAVE_INET_NTOP
@@ -4323,6 +4390,16 @@ channel_read(channel_T *channel, ch_part_T part, char *func)
 #endif
 }
 
+#ifdef FEAT_SOCKETSERVER
+
+    void
+channel_check(channel_T *channel, ch_part_T part)
+{
+    channel_read(channel, part, "channel_check");
+}
+
+#endif
+
 /*
  * Read from RAW or NL "channel"/"part".  Blocks until there is something to
  * read or the timeout expires.
@@ -4465,7 +4542,7 @@ channel_read_json_block(
 	    // received messages.
 	    (void)channel_collapse(channel, part, FALSE);
 
-	more = channel_parse_json(channel, part);
+	more = channel_parse_json(channel, part, false);
 
 	// search for message "id"
 	if (channel_get_json(channel, part, id, TRUE, rettv) == OK)
@@ -5915,4 +5992,17 @@ channel_to_string_buf(typval_T *varp, char_u *buf)
     return buf;
 }
 
+/*
+ * Return the channel with the given ID. Returns NULL if not found.
+ */
+    channel_T *
+channel_find(int ch_id)
+{
+    channel_T *ch;
+    FOR_ALL_CHANNELS(ch)
+	if (ch->ch_id == ch_id)
+	    return ch;
+    return NULL;
+}
+
 #endif // FEAT_JOB_CHANNEL

src/clientserver.c

@@ -15,11 +15,6 @@
 
 #if defined(FEAT_CLIENTSERVER)
 
-# ifdef FEAT_SOCKETSERVER
-#  include <sys/socket.h>
-#  include "sys/un.h"
-# endif
-
 static void cmdsrv_main(int *argc, char **argv, char_u *serverName_arg, char_u **serverStr);
 static char_u *serverMakeName(char_u *arg, char *cmd);
 
@@ -206,23 +201,6 @@ exec_on_server(mparm_T *parmp)
     serverInitMessaging();
 # endif
 
-# ifdef FEAT_SOCKETSERVER
-    // If servername is specified and we are using sockets, always init the
-    // sockt server. We may need to receive replies back to us. If --serverlist
-    // is passed, the socket server will be uninitialized before listing
-    // sockets then initialized after. This is so we don't add our own socket
-    // in the list. This does not happen in serverlist().
-    if ((parmp->serverArg || parmp->serverName_arg != NULL) &&
-	    clientserver_method == CLIENTSERVER_METHOD_SOCKET)
-    {
-	parmp->servername = serverMakeName(parmp->serverName_arg,
-		parmp->argv[0]);
-	if (socket_server_init(parmp->servername) == OK)
-	    TIME_MSG("initialize socket server");
-	made_name = TRUE;
-    }
-# endif
-
     /*
      * When a command server argument was found, execute it.  This may
      * exit Vim when it was successful.  Otherwise it's executed further
@@ -242,10 +220,12 @@ exec_on_server(mparm_T *parmp)
 	parmp->servername = serverMakeName(parmp->serverName_arg,
 		parmp->argv[0]);
 # ifdef MSWIN
-    if (parmp->servername != NULL)
+    if (parmp->servername != NULL && clientserver_method == CLIENTSERVER_METHOD_MSWIN)
     {
 	serverSetName(parmp->servername);
+#  ifndef FEAT_SOCKETSERVER
 	vim_free(parmp->servername);
+#  endif
     }
 # endif
 }
@@ -262,16 +242,31 @@ prepare_server(mparm_T *parmp)
      * Only register nongui-vim's with an explicit --servername argument,
      * or when compiling with autoservername.
      * When running as root --servername is also required.
+     *
+     * If we are Windows and socketserver is being used, then don't use
+     * autoservername, since traditional naming isn't supported.
      */
 
     if (
-#  ifdef FEAT_X11
-	    X_DISPLAY != NULL &&
+#  if defined(FEAT_X11) || (defined(FEAT_SOCKETSERVER) && !defined(MSWIN))
+	    (
+#   ifdef FEAT_X11
+	    X_DISPLAY != NULL
+#   endif
+#   if defined(FEAT_X11) && defined(FEAT_SOCKETSERVER) && !defined(MSWIN)
+	    ||
+#   endif
+#   if defined(FEAT_SOCKETSERVER) && !defined(MSWIN)
+	    clientserver_method == CLIENTSERVER_METHOD_SOCKET
+#   endif
+	    ) &&
 #  endif
-
 	    parmp->servername != NULL && (
 #  if defined(FEAT_AUTOSERVERNAME) || defined(FEAT_GUI)
 		(
+#   if defined(FEAT_SOCKETSERVER) && defined(MSWIN)
+		 clientserver_method != CLIENTSERVER_METHOD_SOCKET &&
+#   endif
 #   if defined(FEAT_AUTOSERVERNAME)
 		    1
 #   else
@@ -284,12 +279,10 @@ prepare_server(mparm_T *parmp)
 #  endif
 		parmp->serverName_arg != NULL))
     {
+
 #  ifdef FEAT_SOCKETSERVER
 	if (clientserver_method == CLIENTSERVER_METHOD_SOCKET)
-	{
-	    if (socket_server_init(parmp->servername) == OK)
-		TIME_MSG("initialize socket server");
-	}
+	    socketserver_start(parmp->servername, false);
 #  endif
 #  ifdef FEAT_X11
 	if (clientserver_method == CLIENTSERVER_METHOD_X11)
@@ -300,10 +293,15 @@ prepare_server(mparm_T *parmp)
 #  endif
 	vim_free(parmp->servername);
     }
-#  ifdef FEAT_X11
     else
-	serverDelayedStartName = parmp->servername;
+    {
+#  ifdef FEAT_X11
+	if (clientserver_method == CLIENTSERVER_METHOD_X11)
+	    serverDelayedStartName = parmp->servername;
+	else
 #  endif
+	    vim_free(parmp->servername);
+    }
 # endif
 
     /*
@@ -343,9 +341,6 @@ cmdsrv_main(
 # define ARGTYPE_SEND		3
     int		silent = FALSE;
     int		tabs = FALSE;
-# ifdef FEAT_SOCKETSERVER
-    char_u	*receiver;
-# endif
 # ifdef MSWIN
     HWND	srv;
 # elif defined(FEAT_X11)
@@ -353,6 +348,9 @@ cmdsrv_main(
 
     setup_term_clip();
 # endif
+# ifdef FEAT_SOCKETSERVER
+    channel_T	*ch = NULL;
+# endif
 
     sname = serverMakeName(serverName_arg, argv[0]);
     if (sname == NULL)
@@ -434,9 +432,8 @@ cmdsrv_main(
 
 # ifdef FEAT_SOCKETSERVER
 	    if (clientserver_method == CLIENTSERVER_METHOD_SOCKET)
-		ret = socket_server_send(
-			sname, *serverStr, NULL, &receiver,
-			0, -1, silent);
+		ret = socketserver_send(sname, *serverStr, NULL, false, -1,
+			silent, &ch);
 # endif
 # ifdef FEAT_X11
 	    if (clientserver_method == CLIENTSERVER_METHOD_X11)
@@ -452,8 +449,10 @@ cmdsrv_main(
 	    }
 # endif
 # ifdef MSWIN
-	    // Win32 always works?
-	    ret = serverSendToVim(sname, *serverStr, NULL, &srv, 0, 0, silent);
+	    if (clientserver_method == CLIENTSERVER_METHOD_MSWIN)
+		// Win32 always works?
+		ret = serverSendToVim(sname, *serverStr, NULL, &srv, 0, 0,
+			silent);
 # endif
 	    if (ret < 0)
 	    {
@@ -513,23 +512,23 @@ cmdsrv_main(
 		    char_u  *p = NULL;
 		    int	    j;
 # ifdef MSWIN
-		    p = serverGetReply(srv, NULL, TRUE, TRUE, 0);
-		    if (p == NULL)
-			break;
-# else
-#  ifdef FEAT_SOCKETSERVER
+		    if (clientserver_method == CLIENTSERVER_METHOD_MSWIN)
+			p = serverGetReply(srv, NULL, TRUE, TRUE, 0);
+# endif
+# ifdef FEAT_SOCKETSERVER
 		    if (clientserver_method == CLIENTSERVER_METHOD_SOCKET
-			    && socket_server_read_reply(receiver, &p, -1) == FAIL)
+			    && (ch == NULL
+				|| socketserver_read_reply(sname, &p, -1, true)
+				== FAIL))
 			    break;
-#  endif
-#  ifdef FEAT_X11
+# endif
+# ifdef FEAT_X11
 		    if (clientserver_method == CLIENTSERVER_METHOD_X11
 			    && serverReadReply(xterm_dpy, srv, &p, TRUE, -1) < 0)
 			    break;
-#  endif
+# endif
 		    if (p == NULL)
 			break;
-# endif
 		    j = atoi((char *)p);
 		    vim_free(p);
 		    if (j >= 0 && j < numFiles)
@@ -543,6 +542,13 @@ cmdsrv_main(
 			done[j] = 1;
 		    }
 		}
+# ifdef FEAT_SOCKETSERVER
+		if (ch != NULL)
+		{
+		    channel_close(ch, false);
+		    channel_clear(ch);
+		}
+# endif
 # ifdef FEAT_GUI_MSWIN
 		Shell_NotifyIcon(NIM_DELETE, &ni);
 # endif
@@ -551,25 +557,24 @@ cmdsrv_main(
 	}
 	else if (STRICMP(argv[i], "--remote-expr") == 0)
 	{
+	    int status = OK;
+
 	    if (i == *argc - 1)
 		mainerr_arg_missing((char_u *)argv[i]);
 # ifdef MSWIN
 	    // Win32 always works?
-	    if (serverSendToVim(sname, (char_u *)argv[i + 1],
+	    if (clientserver_method == CLIENTSERVER_METHOD_MSWIN
+		    && serverSendToVim(sname, (char_u *)argv[i + 1],
 						  &res, NULL, 1, 0, FALSE) < 0)
-# else
-#  ifdef FEAT_SOCKETSERVER
-	    if (clientserver_method == CLIENTSERVER_METHOD_SOCKET)
-	    {
-		if (!socket_server_valid())
-		    mch_errmsg(_("Socket server not online:"
-				"Send expression failed"));
-		else if (socket_server_send(sname, (char_u *)argv[i + 1],
-			    &res, NULL, 1, 0, FALSE) < 0)
-		    goto expr_fail;
-	    }
-#  endif
-#  ifdef FEAT_X11
+		status = FAIL;
+# endif
+# ifdef FEAT_SOCKETSERVER
+	    if (clientserver_method == CLIENTSERVER_METHOD_SOCKET
+		&& socketserver_send(sname, (char_u *)argv[i + 1],
+			    &res, 1, 0, false, NULL) < 0)
+		status = FAIL;
+# endif
+# ifdef FEAT_X11
 	    if (clientserver_method == CLIENTSERVER_METHOD_X11)
 	    {
 		if (xterm_dpy == NULL)
@@ -577,15 +582,11 @@ cmdsrv_main(
 		else if (serverSendToVim(xterm_dpy, sname,
 			    (char_u *)argv[i + 1], &res,
 			    NULL, 1, 0, 1, FALSE) < 0)
-		    goto expr_fail;
+		    status = FAIL;
 	    }
-#  endif
-	    if (FALSE)
 # endif
+	    if (status == FAIL)
 	    {
-# if !defined(MSWIN)
-expr_fail:
-# endif
 		if (res != NULL && *res != NUL)
 		{
 		    // Output error from remote
@@ -598,28 +599,22 @@ expr_fail:
 	else if (STRICMP(argv[i], "--serverlist") == 0)
 	{
 # ifdef MSWIN
-	    // Win32 always works?
-	    res = serverGetVimNames();
-# else
-#  ifdef FEAT_SOCKETSERVER
+	    if (clientserver_method == CLIENTSERVER_METHOD_MSWIN)
+		// Win32 always works?
+		res = serverGetVimNames();
+# endif
+# ifdef FEAT_SOCKETSERVER
 	    if (clientserver_method == CLIENTSERVER_METHOD_SOCKET)
-	    {
-		int was_init = socket_server_valid();
-
-		// Don't want to add ourselves to the list. So shutdown the
-		// server before listing then startup back again.
-		socket_server_uninit();
-		res = socket_server_list_sockets();
-
-		if (was_init)
-		    socket_server_init(NULL);
-	    }
+#  ifdef MSWIN
+		res = vim_strsave((char_u *)"");
+#  else
+		res = socketserver_list();
 #  endif
-#  ifdef FEAT_X11
+# endif
+# ifdef FEAT_X11
 	    if (clientserver_method == CLIENTSERVER_METHOD_X11 &&
 		    xterm_dpy != NULL)
 		res = serverGetVimNames(xterm_dpy);
-#  endif
 # endif
 	    if (did_emsg)
 		mch_errmsg("\n");
@@ -648,9 +643,6 @@ expr_fail:
 
     if (didone)
     {
-# ifdef FEAT_SOCKETSERVER
-	socket_server_uninit();
-# endif
 	display_errors();	// display any collected messages
 	exit(exiterr);	// Mission accomplished - get out
     }
@@ -807,12 +799,12 @@ serverMakeName(char_u *arg, char *cmd)
     if (arg != NULL && *arg != NUL)
     {
 # ifdef FEAT_SOCKETSERVER
-	// If we are using a socket server, we want to preserve the original
-	// name if it is a path, else uppercase it if its just a generic name.
+	// When using socketserver backend, do not change the name if path or
+	// channel address.
 	if (clientserver_method == CLIENTSERVER_METHOD_SOCKET)
 	{
-	    if (arg[0] == '/' || STRNCMP(arg, "./", 2) == 0 ||
-		    STRNCMP(arg, "../", 3) == 0)
+	    if (STRNICMP(arg, "channel:", 8) == 0 || arg[0] == '/' ||
+		    STRNCMP(arg, "./", 2) == 0 || STRNCMP(arg, "../", 3) == 0)
 		p = vim_strsave(arg);
 	    else
 		p = vim_strsave_up(arg);
@@ -853,6 +845,8 @@ make_connection(void)
     static int
 check_connection(void)
 {
+    if (clientserver_method != CLIENTSERVER_METHOD_X11)
+	return OK;
     make_connection();
     if (X_DISPLAY == NULL)
     {
@@ -878,10 +872,8 @@ remote_common(typval_T *argvars, typval_T *rettv, int expr)
 #  ifdef FEAT_X11
     Window	w;
 #  endif
-#  ifdef FEAT_SOCKETSERVER
-    char_u	*client = NULL;
-#  endif
 # endif
+    int		ret = OK;
 
     if (check_restricted() || check_secure())
 	return;
@@ -899,35 +891,29 @@ remote_common(typval_T *argvars, typval_T *rettv, int expr)
 	return;		// type error; errmsg already given
     keys = tv_get_string_buf(&argvars[1], buf);
 # ifdef MSWIN
-    if (serverSendToVim(server_name, keys, &r, &w, expr, timeout, TRUE) < 0)
-# else
-#  ifdef FEAT_SOCKETSERVER
-    if (clientserver_method == CLIENTSERVER_METHOD_SOCKET)
-	if (socket_server_send(server_name, keys, &r, &client, expr,
-		    timeout * 1000, TRUE) < 0)
-	    goto fail;
-#  endif
-#  ifdef FEAT_X11
+    if (clientserver_method == CLIENTSERVER_METHOD_MSWIN
+	    && serverSendToVim(server_name, keys, &r, &w, expr,
+		timeout, TRUE) < 0)
+	ret = FAIL;
+# endif
+# ifdef FEAT_SOCKETSERVER
+    if (clientserver_method == CLIENTSERVER_METHOD_SOCKET
+	&& socketserver_send(server_name, keys, &r, expr,
+	    timeout * 1000, true, NULL) < 0)
+	ret = FAIL;
+# endif
+# ifdef FEAT_X11
     if (clientserver_method == CLIENTSERVER_METHOD_X11)
 	if (serverSendToVim(X_DISPLAY, server_name, keys, &r, &w, expr, timeout,
 		    0, TRUE) < 0)
-	    goto fail;
-#  endif
+	ret = FAIL;
 # endif
-# if !defined(MSWIN)
-    if (FALSE)
+    if (ret == FAIL)
     {
-fail:
-# else
-    {
-# endif
 	if (r != NULL)
 	{
 	    emsg((char *)r);	// sending worked but evaluation failed
 	    vim_free(r);
-# ifdef FEAT_SOCKETSERVER
-	    vim_free(client);
-# endif
 	}
 	else
 	    semsg(_(e_unable_to_send_to_str), server_name);
@@ -939,40 +925,42 @@ fail:
     if (argvars[2].v_type != VAR_UNKNOWN)
     {
 	dictitem_T	v;
-# if defined(FEAT_SOCKETSERVER)
-	struct sockaddr_un addr;
-	char_u		str[sizeof(addr.sun_path)];
-# else
-	char_u		str[30];
+# if defined(MSWIN) || defined(FEAT_X11)
+	char_u		sbuf[30];
 # endif
+	char_u		*str = NULL;
 	char_u		*idvar;
 
 	idvar = tv_get_string_chk(&argvars[2]);
 	if (idvar != NULL && *idvar != NUL)
 	{
-	    str[0] = NUL;
 # ifdef MSWIN
-	    sprintf((char *)str, PRINTF_HEX_LONG_U, (long_u)w);
-# else
-#  ifdef FEAT_X11
-	    if (clientserver_method == CLIENTSERVER_METHOD_X11)
-		sprintf((char *)str, PRINTF_HEX_LONG_U, (long_u)w);
-#  endif
-#  ifdef FEAT_SOCKETSERVER
-	    if (clientserver_method == CLIENTSERVER_METHOD_SOCKET)
-		vim_snprintf((char *)str, sizeof(addr.sun_path),
-			"%s", client);
-#  endif
+	    if (clientserver_method == CLIENTSERVER_METHOD_MSWIN)
+	    {
+		sprintf((char *)sbuf, PRINTF_HEX_LONG_U, (long_u)w);
+		str = sbuf;
+	    }
 # endif
+# ifdef FEAT_X11
+	    if (clientserver_method == CLIENTSERVER_METHOD_X11)
+	    {
+		sprintf((char *)sbuf, PRINTF_HEX_LONG_U, (long_u)w);
+		str = sbuf;
+	    }
+# endif
+# ifdef FEAT_SOCKETSERVER
+	    if (clientserver_method == CLIENTSERVER_METHOD_SOCKET)
+		str = server_name;
+# endif
+	    if (str == NULL)
+		str = (char_u *)"";
+
 	    v.di_tv.v_type = VAR_STRING;
 	    v.di_tv.vval.v_string = vim_strsave(str);
 	    set_var(idvar, &v.di_tv, FALSE);
 	    vim_free(v.di_tv.vval.v_string);
 	}
     }
-# ifdef FEAT_SOCKETSERVER
-    vim_free(client);
-# endif
 }
 #endif
 
@@ -1054,20 +1042,23 @@ f_remote_peek(typval_T *argvars UNUSED, typval_T *rettv)
     if (serverid == NULL)
 	return;		// type error; errmsg already given
 #  ifdef MSWIN
-    sscanf((const char *)serverid, SCANF_HEX_LONG_U, &n);
-    if (n == 0)
-	rettv->vval.v_number = -1;
-    else
+    if (clientserver_method == CLIENTSERVER_METHOD_MSWIN)
     {
-	s = serverGetReply((HWND)n, FALSE, FALSE, FALSE, 0);
-	rettv->vval.v_number = (s != NULL);
+	sscanf((const char *)serverid, SCANF_HEX_LONG_U, &n);
+	if (n == 0)
+	    rettv->vval.v_number = -1;
+	else
+	{
+	    s = serverGetReply((HWND)n, FALSE, FALSE, FALSE, 0);
+	    rettv->vval.v_number = (s != NULL);
+	}
     }
-#  else
-#   ifdef FEAT_SOCKETSERVER
+#  endif
+#  ifdef FEAT_SOCKETSERVER
     if (clientserver_method == CLIENTSERVER_METHOD_SOCKET)
-	rettv->vval.v_number = socket_server_peek_reply(serverid, &s);
-#   endif
-#   ifdef FEAT_X11
+	rettv->vval.v_number = socketserver_peek_reply(serverid, &s);
+#  endif
+#  ifdef FEAT_X11
     if (clientserver_method == CLIENTSERVER_METHOD_X11)
     {
 	if (check_connection() == FAIL)
@@ -1076,7 +1067,6 @@ f_remote_peek(typval_T *argvars UNUSED, typval_T *rettv)
 	rettv->vval.v_number = serverPeekReply(X_DISPLAY,
 		serverStrToWin(serverid), &s);
     }
-#   endif
 #  endif
 
     if (argvars[1].v_type != VAR_UNKNOWN && rettv->vval.v_number > 0)
@@ -1121,24 +1111,27 @@ f_remote_read(typval_T *argvars UNUSED, typval_T *rettv)
 	    timeout = tv_get_number(&argvars[1]);
 
 #  ifdef MSWIN
-	sscanf((char *)serverid, SCANF_HEX_LONG_U, &n);
-	if (n != 0)
-	    r = serverGetReply((HWND)n, FALSE, TRUE, TRUE, timeout);
-	if (r == NULL)
-	    emsg(_(e_unable_to_read_server_reply));
-#  else
-#   ifdef FEAT_SOCKETSERVER
+	if (clientserver_method == CLIENTSERVER_METHOD_MSWIN)
+	{
+	    sscanf((char *)serverid, SCANF_HEX_LONG_U, &n);
+	    if (n != 0)
+		r = serverGetReply((HWND)n, FALSE, TRUE, TRUE, timeout);
+	    if (r == NULL)
+		emsg(_(e_unable_to_read_server_reply));
+	}
+#  endif
+#  ifdef FEAT_SOCKETSERVER
 	if (clientserver_method == CLIENTSERVER_METHOD_SOCKET &&
-		socket_server_read_reply(serverid, &r, timeout * 1000) == FAIL)
+		socketserver_read_reply(serverid, &r, timeout * 1000, false)
+		== FAIL)
 	    emsg(_(e_unable_to_read_server_reply));
-#   endif
-#   ifdef FEAT_X11
+#  endif
+#  ifdef FEAT_X11
 	if (clientserver_method == CLIENTSERVER_METHOD_X11 &&
 		(check_connection() == FAIL
 		|| serverReadReply(X_DISPLAY, serverStrToWin(serverid),
 						       &r, FALSE, timeout) < 0))
 	    emsg(_(e_unable_to_read_server_reply));
-#   endif
 #  endif
     }
 # endif
@@ -1184,17 +1177,17 @@ f_remote_startserver(typval_T *argvars UNUSED, typval_T *rettv UNUSED)
 
     char_u *server = tv_get_string_chk(&argvars[0]);
 #  ifdef MSWIN
-    serverSetName(server);
-#  else
-#   ifdef FEAT_SOCKETSERVER
+    if (clientserver_method == CLIENTSERVER_METHOD_MSWIN)
+	serverSetName(server);
+#  endif
+#  ifdef FEAT_SOCKETSERVER
     if (clientserver_method == CLIENTSERVER_METHOD_SOCKET)
-	socket_server_init(server);
-#   endif
-#   ifdef FEAT_X11
+	socketserver_start(server, true);
+#  endif
+#  ifdef FEAT_X11
     if (clientserver_method == CLIENTSERVER_METHOD_X11 &&
 	    check_connection() == OK)
 	serverRegisterName(X_DISPLAY, server);
-#   endif
 #  endif
 
 # else
@@ -1209,6 +1202,7 @@ f_server2client(typval_T *argvars UNUSED, typval_T *rettv)
     char_u	buf[NUMBUFLEN];
     char_u	*server;
     char_u	*reply;
+    int		ret = OK;
 
     rettv->vval.v_number = -1;
     if (check_restricted() || check_secure())
@@ -1226,28 +1220,22 @@ f_server2client(typval_T *argvars UNUSED, typval_T *rettv)
 
 #  ifdef FEAT_SOCKETSERVER
     if (clientserver_method == CLIENTSERVER_METHOD_SOCKET &&
-	    socket_server_send_reply(server, reply) == FAIL)
-	goto fail;
+	    socketserver_send_reply(server, reply) == FAIL)
+	ret = FAIL;
 #  endif
-
 #  ifdef FEAT_X11
-    if (clientserver_method == CLIENTSERVER_METHOD_X11 &&
-	    check_connection() == FAIL)
-	return;
-
     if (clientserver_method == CLIENTSERVER_METHOD_X11 &&
 	    serverSendReply(server, reply) < 0)
+	ret = FAIL;
 #  endif
 #  ifdef MSWIN
-    if (serverSendReply(server, reply) < 0)
-#  endif
-#  if defined(FEAT_SOCKETSERVER) && !defined(FEAT_X11) && !defined(MSWIN)
-    if (FALSE)
+    if (clientserver_method == CLIENTSERVER_METHOD_MSWIN
+	    && serverSendReply(server, reply) < 0)
+	ret = FAIL;
 #  endif
+
+    if (ret == FAIL)
     {
-#  ifdef FEAT_SOCKETSERVER
-fail:
-#  endif
 	emsg(_(e_unable_to_send_to_client));
 	return;
     }
@@ -1264,20 +1252,24 @@ f_serverlist(typval_T *argvars UNUSED, typval_T *rettv)
 
 # ifdef FEAT_CLIENTSERVER
 #  ifdef MSWIN
-    r = serverGetVimNames();
-#  else
-#   ifdef FEAT_SOCKETSERVER
+    if (clientserver_method == CLIENTSERVER_METHOD_MSWIN)
+	r = serverGetVimNames();
+#  endif
+#  ifdef FEAT_SOCKETSERVER
     if (clientserver_method == CLIENTSERVER_METHOD_SOCKET)
-	r = socket_server_list_sockets();
+#   ifdef MSWIN
+	r = vim_strsave((char_u *)"");
+#   else
+	r = socketserver_list();
 #   endif
-#   ifdef FEAT_X11
+#  endif
+#  ifdef FEAT_X11
     if (clientserver_method == CLIENTSERVER_METHOD_X11)
     {
     make_connection();
     if (X_DISPLAY != NULL)
 	r = serverGetVimNames(X_DISPLAY);
     }
-#   endif
 #  endif
 # endif
     rettv->v_type = VAR_STRING;

src/configure.ac

@@ -2363,22 +2363,6 @@ if test "$enable_autoservername" = "yes"; then
   AC_DEFINE(FEAT_AUTOSERVERNAME)
 fi
 
-AC_MSG_CHECKING(--enable-socketserver argument)
-AC_ARG_ENABLE(socketserver,
-	[  --enable-socketserver Use sockets for clientserver communication.],
-	[enable_socketserver=$enableval],
-	AS_IF([test "x$features" = xtiny],
-			[enable_socketserver=no_msg
-			 AC_MSG_RESULT([cannot use socketserver with tiny features])],
-			[enable_socketserver=yes]))
-
-if test "$enable_socketserver" = "yes"; then
-  AC_DEFINE(WANT_SOCKETSERVER)
-  AC_MSG_RESULT([yes])
-elif test "$enable_socketserver" = "no"; then
-  AC_MSG_RESULT([no])
-fi
-
 AC_MSG_CHECKING(--enable-multibyte argument)
 AC_ARG_ENABLE(multibyte,
 	[  --enable-multibyte      Include multibyte editing support.], ,

src/errors.h

@@ -1139,7 +1139,7 @@ EXTERN char e_cant_read_postscript_resource_file_str[]
 	INIT(= N_("E457: Can't read PostScript resource file \"%s\""));
 #endif
 // E458 unused
-#if defined(UNIX) || defined(FEAT_SESSION)
+#if defined(UNIX) || defined(FEAT_SESSION) || defined(FEAT_SOCKETSERVER)
 EXTERN char e_cannot_go_back_to_previous_directory[]
 	INIT(= N_("E459: Cannot go back to previous directory"));
 #endif
@@ -3777,16 +3777,14 @@ EXTERN char e_diff_anchors_with_hidden_windows[]
 	INIT(= N_("E1562: Diff anchors cannot be used with hidden diff windows"));
 #endif
 #ifdef FEAT_SOCKETSERVER
-EXTERN char e_socket_path_too_big[]
-	INIT(= N_("E1563: Socket path is too big"));
 EXTERN char e_socket_name_no_slashes[]
-	INIT(= N_("E1564: Socket name cannot have slashes in it without being a path"));
+	INIT(= N_("E1564: Socket name '%s' cannot have slashes in it without being a path"));
 EXTERN char e_socket_server_not_online[]
 	INIT(= N_("E1565: Socket server is not online, call remote_startserver() first"));
 EXTERN char e_socket_server_failed_connecting[]
-	INIT(= N_("E1566: Failed connecting to socket %s: %s"));
-EXTERN char e_socket_server_unavailable[]
-	INIT(= N_("E1567: Cannot start socket server, socket path is unavailable"));
+	INIT(= N_("E1566: Failed connecting to socket '%s'"));
+EXTERN char e_socket_server_version_mismatch[]
+	INIT(= N_("E1567: Socket server protocol version mismatch, check what Vim version you are using"));
 #endif
 EXTERN char e_osc_response_timed_out[]
 	INIT(= N_("E1568: OSC command response timed out: %.*s"));

src/feature.h

@@ -953,9 +953,16 @@
 #endif
 
 /*
- * +socketserver	 Use UNIX domain sockets for clientserver communication
+ * The +channel feature requires +eval.
  */
-#if defined(UNIX) && defined(WANT_SOCKETSERVER)
+#if !defined(FEAT_EVAL) && defined(FEAT_JOB_CHANNEL)
+# undef FEAT_JOB_CHANNEL
+#endif
+
+/*
+ * +socketserver	 Use channels for clientserver communication
+ */
+#if (defined(UNIX) || defined(MSWIN)) && defined(FEAT_JOB_CHANNEL)
 # define FEAT_SOCKETSERVER
 #endif
 
@@ -966,6 +973,9 @@
 #if (defined(MSWIN) || defined(FEAT_XCLIPBOARD) || defined(FEAT_SOCKETSERVER)) \
     && defined(FEAT_EVAL)
 # define FEAT_CLIENTSERVER
+# if defined(FEAT_SOCKETSERVER) && (defined(FEAT_XCLIPBOARD) || defined(MSWIN))
+#  define FEAT_CLIENTSERVER_BACKENDS
+# endif
 #endif
 
 /*
@@ -1053,14 +1063,6 @@
  * +tgetent
  */
 
-
-/*
- * The +channel feature requires +eval.
- */
-#if !defined(FEAT_EVAL) && defined(FEAT_JOB_CHANNEL)
-# undef FEAT_JOB_CHANNEL
-#endif
-
 /*
  * The Netbeans feature requires +eval and +job_channel
  */

src/gc.c

@@ -208,6 +208,9 @@ garbage_collect(int testing)
 #ifdef FEAT_NETBEANS_INTG
     abort = abort || set_ref_in_nb_channel(copyID);
 #endif
+#ifdef FEAT_SOCKETSERVER
+    abort = abort || set_ref_in_socketserver_channel(copyID);
+#endif
 
 #ifdef FEAT_TIMERS
     abort = abort || set_ref_in_timer(copyID);

src/getchar.c

@@ -2650,6 +2650,9 @@ parse_queued_messages(void)
 	// Process the queued netbeans messages.
 	netbeans_parse_messages();
 # endif
+# ifdef FEAT_SOCKETSERVER
+	socketserver_parse_messages();
+# endif
 # ifdef FEAT_JOB_CHANNEL
 	// Write any buffer lines still to be written.
 	channel_write_any_lines();

src/globals.h

@@ -2122,25 +2122,28 @@ EXTERN int wayland_no_connect INIT(= FALSE);
 
 #endif
 
-#if defined(FEAT_CLIENTSERVER) && !defined(MSWIN)
+#if defined(FEAT_CLIENTSERVER)
 
 // Backend for clientserver functionality
 typedef enum {
     CLIENTSERVER_METHOD_NONE,
+# ifdef FEAT_X11
     CLIENTSERVER_METHOD_X11,
+# endif
+# ifdef MSWIN
+    CLIENTSERVER_METHOD_MSWIN,
+# endif
+# ifdef FEAT_SOCKETSERVER
     CLIENTSERVER_METHOD_SOCKET
+# endif
 } clientserver_method_T;
 
-// Default to X11 if compiled with support for it, else use socket server.
-# if defined(FEAT_X11) && defined(FEAT_SOCKETSERVER)
 EXTERN clientserver_method_T clientserver_method
-# else
-// Since we aren't going to be changing clientserver_method, make it constant to
-// allow compiler optimizations.
-EXTERN const clientserver_method_T clientserver_method
-# endif
+
 # ifdef FEAT_X11
 INIT(= CLIENTSERVER_METHOD_X11);
+# elif defined(MSWIN)
+INIT(= CLIENTSERVER_METHOD_MSWIN);
 # elif defined(FEAT_SOCKETSERVER)
 INIT(= CLIENTSERVER_METHOD_SOCKET);
 # else

src/gui.c

@@ -158,12 +158,6 @@ gui_start(char_u *arg UNUSED)
 	choose_clipmethod();
 #endif
 
-#if defined(FEAT_SOCKETSERVER) && defined(FEAT_GUI_GTK)
-    // Install socket server listening socket if we are running it
-    if (socket_server_valid())
-	gui_gtk_init_socket_server();
-#endif
-
 #ifdef FEAT_GUI_MSWIN
     // Enable fullscreen mode
     if (vim_strchr(p_go, GO_FULLSCREEN) != NULL)

src/gui_gtk_x11.c

@@ -80,13 +80,6 @@ extern void bonobo_dock_item_set_behavior(BonoboDockItem *dock_item, BonoboDockI
 # include <X11/Sunkeysym.h>
 #endif
 
-#ifdef FEAT_SOCKETSERVER
-# include <glib-unix.h>
-
-// Used to track the source for the listening socket
-static uint socket_server_source_id = 0;
-#endif
-
 /*
  * Easy-to-use macro for multihead support.
  */
@@ -2690,54 +2683,6 @@ global_event_filter(GdkXEvent *xev,
 }
 #endif // !USE_GNOME_SESSION
 
-#if defined(FEAT_SOCKETSERVER)
-
-/*
- * Callback for new events from the socket server listening socket
- */
-    static int
-socket_server_poll_in(int fd UNUSED, GIOCondition cond, void *user_data UNUSED)
-{
-    if (cond & G_IO_IN)
-	socket_server_accept_client();
-    else if (cond & (G_IO_ERR | G_IO_HUP))
-    {
-	socket_server_uninit();
-	return FALSE;
-    }
-
-    return TRUE;
-}
-
-/*
- * Initialize socket server for use in the GUI (does not actually initialize the
- * socket server, only attaches a source).
- */
-    void
-gui_gtk_init_socket_server(void)
-{
-    if (socket_server_source_id > 0)
-	return;
-    // Register source for file descriptor to global default context
-    socket_server_source_id = g_unix_fd_add(socket_server_get_fd(),
-	    G_IO_IN | G_IO_ERR | G_IO_HUP, socket_server_poll_in, NULL);
-}
-
-/*
- * Remove the source for the socket server listening socket.
- */
-    void
-gui_gtk_uninit_socket_server(void)
-{
-    if (socket_server_source_id > 0)
-    {
-	g_source_remove(socket_server_source_id);
-	socket_server_source_id = 0;
-    }
-}
-
-#endif
-
     static GdkPixbuf *
 pixbuf_new_from_png_data(const unsigned char *data, unsigned int len)
 {

src/json.c

@@ -51,6 +51,8 @@ json_encode(typval_T *val, int options)
     // Store bytes in the growarray.
     ga_init2(&ga, 1, 4000);
     json_encode_gap(&ga, val, options);
+    if (options & JSON_NL)
+	ga_append(&ga, NL);
     ga_append(&ga, NUL);
     return ga.ga_data;
 }

src/main.c

@@ -1844,6 +1844,9 @@ getout(int exitval)
 #ifdef FEAT_NETBEANS_INTG
     netbeans_end();
 #endif
+#ifdef FEAT_SOCKETSERVER
+    socketserver_stop();
+#endif
 #ifdef FEAT_CSCOPE
     cs_end();
 #endif
@@ -1910,7 +1913,7 @@ early_arg_scan(mparm_T *parmp UNUSED)
 		gui.dofork = false;
 #  endif
 	}
-#  if defined(FEAT_X11) && defined(FEAT_SOCKETSERVER)
+#  ifdef FEAT_CLIENTSERVER_BACKENDS
 	else if (STRNICMP(argv[i], "--clientserver", 14) == 0)
 	{
 	    char_u *arg;
@@ -1920,8 +1923,14 @@ early_arg_scan(mparm_T *parmp UNUSED)
 
 	    if (STRICMP(arg, "socket") == 0)
 		clientserver_method = CLIENTSERVER_METHOD_SOCKET;
+#   ifdef FEAT_X11
 	    else if (STRICMP(arg, "x11") == 0)
 		clientserver_method = CLIENTSERVER_METHOD_X11;
+#   endif
+#   ifdef MSWIN
+	    else if (STRICMP(arg, "mswin") == 0)
+		clientserver_method = CLIENTSERVER_METHOD_MSWIN;
+#   endif
 	    else
 		mainerr(ME_UNKNOWN_OPTION, arg);
 	}
@@ -2247,9 +2256,9 @@ command_line_scan(mparm_T *parmp)
 		    ; // already processed -- no arg
 		else if (STRNICMP(argv[0] + argv_idx, "servername", 10) == 0
 		       || STRNICMP(argv[0] + argv_idx, "serversend", 10) == 0
-#  if defined(FEAT_X11) && defined(FEAT_SOCKETSERVER)
+		       // Don't put this under FEAT_CLIENTSERVER_BACKENDS, just
+		       // let it be ignored. Makes tests less complicated
 		       || STRNICMP(argv[0] + argv_idx, "clientserver", 12) == 0
-#  endif
 		       )
 		{
 		    // already processed -- snatch the following arg
@@ -3747,8 +3756,8 @@ usage(void)
     main_msg(_("-Y\t\t\tDo not connect to Wayland compositor"));
 # endif
 # ifdef FEAT_CLIENTSERVER
-#  if defined(FEAT_X11) && defined(FEAT_SOCKETSERVER)
-    main_msg(_("--clientserver <socket|x11> Backend for clientserver communication"));
+#  ifdef FEAT_CLIENTSERVER_BACKENDS
+    main_msg(_("--clientserver <socket|x11|mswin> Backend for clientserver communication"));
 #  endif
     main_msg(_("--remote <files>\tEdit <files> in a Vim server if possible"));
     main_msg(_("--remote-silent <files>  Same, don't complain if there is no server"));

src/po/vim.pot

@@ -254,9 +254,6 @@ msgstr ""
 msgid "%d of %d edited"
 msgstr ""
 
-msgid "Socket server not online:Send expression failed"
-msgstr ""
-
 msgid "No display: Send expression failed.\n"
 msgstr ""
 
@@ -1722,7 +1719,8 @@ msgstr ""
 msgid "-Y\t\t\tDo not connect to Wayland compositor"
 msgstr ""
 
-msgid "--clientserver <socket|x11> Backend for clientserver communication"
+msgid ""
+"--clientserver <socket|x11|mswin> Backend for clientserver communication"
 msgstr ""
 
 msgid "--remote <files>\tEdit <files> in a Vim server if possible"
@@ -2531,10 +2529,6 @@ msgstr ""
 msgid "XSMP SmcOpenConnection failed: %s"
 msgstr ""
 
-#, c-format
-msgid "Failed creating socket directory: %s"
-msgstr ""
-
 msgid "At line"
 msgstr ""
 
@@ -2806,6 +2800,10 @@ msgstr ""
 msgid " (not supported)"
 msgstr ""
 
+#, c-format
+msgid "Failed creating socket directory: %s"
+msgstr ""
+
 #, c-format
 msgid "Warning: Cannot find word list \"%s_%s.spl\" or \"%s_ascii.spl\""
 msgstr ""
@@ -8834,20 +8832,20 @@ msgstr ""
 msgid "E1562: Diff anchors cannot be used with hidden diff windows"
 msgstr ""
 
-msgid "E1563: Socket path is too big"
-msgstr ""
-
-msgid "E1564: Socket name cannot have slashes in it without being a path"
+#, c-format
+msgid "E1564: Socket name '%s' cannot have slashes in it without being a path"
 msgstr ""
 
 msgid "E1565: Socket server is not online, call remote_startserver() first"
 msgstr ""
 
 #, c-format
-msgid "E1566: Failed connecting to socket %s: %s"
+msgid "E1566: Failed connecting to socket '%s'"
 msgstr ""
 
-msgid "E1567: Cannot start socket server, socket path is unavailable"
+msgid ""
+"E1567: Socket server protocol version mismatch, check what Vim version you "
+"are using"
 msgstr ""
 
 #, c-format

src/proto.h

@@ -277,6 +277,9 @@ void mbyte_im_set_active(int active_arg);
 #  include "job.pro"
 #  include "channel.pro"
 # endif
+# ifdef FEAT_SOCKETSERVER
+#  include "socketserver.pro"
+# endif
 
 # ifdef FEAT_EVAL
 // Not generated automatically so that we can add an extra attribute.

src/proto/channel.pro

@@ -7,15 +7,18 @@ int channel_unref(channel_T *channel);
 int free_unused_channels_contents(int copyID, int mask);
 void free_unused_channels(int copyID, int mask);
 void channel_gui_register_all(void);
+channel_T *channel_open_unix(const char *path, void (*nb_close_cb)(void));
 channel_T *channel_open(const char *hostname, int port, int waittime, void (*nb_close_cb)(void));
+int channel_parse_socketserver_address(char_u *address, int *port, char_u **unix_path, bool quiet);
 channel_T *channel_listen_func(typval_T *argvars);
 channel_T *channel_listen(int port_in, void (*nb_close_cb)(void));
-channel_T *channel_listen_unix(char *path, void (*nb_close_cb)(void));
+channel_T *channel_listen_unix(char *path, void (*nb_close_cb)(void), bool replace);
 void ch_close_part(channel_T *channel, ch_part_T part);
 void channel_set_pipes(channel_T *channel, sock_T in, sock_T out, sock_T err);
 void channel_set_job(channel_T *channel, job_T *job, jobopt_T *options);
 void channel_write_in(channel_T *channel);
 void channel_buffer_free(buf_T *buf);
+void channel_write_input(channel_T *channel);
 void channel_write_any_lines(void);
 void channel_write_new_lines(buf_T *buf);
 readq_T *channel_peek(channel_T *channel, ch_part_T part);
@@ -23,11 +26,15 @@ char_u *channel_first_nl(readq_T *node);
 char_u *channel_get(channel_T *channel, ch_part_T part, int *outlen);
 void channel_consume(channel_T *channel, ch_part_T part, int len);
 int channel_collapse(channel_T *channel, ch_part_T part, int want_nl);
+int channel_fill(js_read_T *reader);
+int channel_parse_json(channel_T *channel, ch_part_T part, bool socketserver);
+void remove_json_node(jsonq_T *head, jsonq_T *node);
 int channel_can_write_to(channel_T *channel);
 int channel_is_open(channel_T *channel);
 void channel_close(channel_T *channel, int invoke_close_cb);
 void channel_clear(channel_T *channel);
 void channel_free_all(void);
+void channel_check(channel_T *channel, ch_part_T part);
 int channel_in_blocking_wait(void);
 channel_T *get_channel_arg(typval_T *tv, int check_open, int reading, ch_part_T part);
 void channel_handle_events(int only_keep_open);
@@ -59,4 +66,5 @@ void f_ch_sendraw(typval_T *argvars, typval_T *rettv);
 void f_ch_setoptions(typval_T *argvars, typval_T *rettv);
 void f_ch_status(typval_T *argvars, typval_T *rettv);
 char_u *channel_to_string_buf(typval_T *varp, char_u *buf);
+channel_T *channel_find(int ch_id);
 /* vim: set ft=c : */

src/proto/gui_gtk_x11.pro

@@ -8,8 +8,6 @@ void gui_mch_stop_blink(int may_call_gui_update_cursor);
 void gui_mch_start_blink(void);
 int gui_mch_early_init_check(int give_message);
 int gui_mch_init_check(void);
-void gui_gtk_init_socket_server(void);
-void gui_gtk_uninit_socket_server(void);
 void gui_mch_set_dark_theme(int dark);
 void gui_mch_show_tabline(int showit);
 int gui_mch_showing_tabline(void);

src/proto/os_unix.pro

@@ -96,15 +96,4 @@ void stop_timeout(void);
 volatile sig_atomic_t *start_timeout(long msec);
 void delete_timer(void);
 int mch_create_anon_file(void);
-int socket_server_init(char_u *name);
-void socket_server_uninit(void);
-char_u *socket_server_list_sockets(void);
-int socket_server_accept_client(void);
-int socket_server_valid(void);
-int socket_server_send(char_u *name, char_u *str, char_u **result, char_u **receiver, int is_expr, int timeout, int silent);
-int socket_server_read_reply(char_u *client, char_u **str, int timeout);
-int socket_server_peek_reply(char_u *sender, char_u **str);
-int socket_server_send_reply(char_u *client, char_u *str);
-int socket_server_get_fd(void);
-int socket_server_waiting_accept(void);
 /* vim: set ft=c : */

src/proto/socketserver.pro

@@ -0,0 +1,11 @@
+/* socketserver.c */
+int socketserver_start(char_u *name, bool quiet);
+void socketserver_stop(void);
+char_u *socketserver_list(void);
+int set_ref_in_socketserver_channel(int copyID);
+void socketserver_parse_messages(void);
+int socketserver_send(char_u *name, char_u *str, char_u **result, bool is_expr, int timeout, bool silent, channel_T **ch);
+int socketserver_send_reply(char_u *client, char_u *str);
+int socketserver_read_reply(char_u *client, char_u **str, int timeout, bool remotewait);
+int socketserver_peek_reply(char_u *sender, char_u **str);
+/* vim: set ft=c : */

src/structs.h

@@ -2795,6 +2795,13 @@ struct channel_S {
     void	(*ch_nb_close_cb)(void);
 				// callback for Netbeans when channel is
 				// closed
+#ifdef FEAT_SOCKETSERVER
+    bool	ch_socketserver; // If channel is used by socketserver
+    void	(*ch_ss_close_cb)(channel_T *);
+    void	(*ch_ss_accept_cb)(channel_T *);
+    channel_T	*ch_ss_next;
+    channel_T	*ch_ss_prev;
+#endif
 
 #ifdef MSWIN
     int		ch_named_pipe;	// using named pipe instead of pty

src/testdir/dumps/Test_clientserver_1.dump

@@ -0,0 +1,8 @@
+|~+0#4040ff13#ffffff0| @73
+|~| @73
+|~| @73
+|E+0#ffffff16#e000002|1|5|6|7|:| |S|o|c|k|e|t| |s|e|r|v|e|r| |p|r|o|t|o|c|o|l| |v|e|r|s|i|o|n| |m|i|s|m|a|t|c|h|,| |c|h|e|c|k| |w|h|a|t| |V|i|m| |v|e|r|s|i|o|n| |y|o|u| 
+|a|r|e| |u|s|i|n|g| +0#0000000#ffffff0@65
+|E+0#ffffff16#e000002|2|4|1|:| |U|n|a|b|l|e| |t|o| |s|e|n|d| |t|o| |c|h|a|n@1|e|l|:|2|0@2| +0#0000000#ffffff0@38
+@75
+|P+0#00e0003&|r|e|s@1| |E|N|T|E|R| |o|r| |t|y|p|e| |c|o|m@1|a|n|d| |t|o| |c|o|n|t|i|n|u|e> +0#0000000&@35

src/testdir/test_clientserver.vim

@@ -1,5 +1,6 @@
 " Tests for the +clientserver feature.
 
+source util/screendump.vim
 CheckFeature job
 
 if !has('clientserver')
@@ -10,10 +11,6 @@ CheckFeature clientserver
 
 source util/shared.vim
 
-" Unlike X11, we need the socket server running if we want to send commands to
-" a server via sockets.
-RunSocketServer
-
 func Check_X11_Connection()
   if has('x11')
     CheckX11
@@ -192,9 +189,9 @@ func Test_client_server()
 
   " When using socket server, server id is not a number, but the path to the
   " socket.
-  if has('socketserver') && !has('X11')
-    call assert_fails("let x = remote_read('vim/10')", ['E573:.*vim/10'])
-    call assert_fails("call server2client('a/b/c', 'xyz')", ['E573:.*a/b/c'])
+  if (has('socketserver') && !has('X11') && !has('win32')) || index(v:argv, "socket") != -1
+    call assert_fails("let x = remote_read('vim/10')", ['E1564:'])
+    call assert_fails("call server2client('x/b/c', 'xyz')", ['E1564:'])
   else
     call assert_fails("let x = remote_read('vim10')",
           \ has('unix') ? ['E573:.*vim10'] : 'E277:')
@@ -246,89 +243,65 @@ func Test_client_server_stopinsert()
   endtry
 endfunc
 
-" Test if socket server and X11 backends can be chosen and work properly.
-func Test_client_server_x11_and_socket_server()
-  CheckNotMSWindows
-  CheckFeature socketserver
-  CheckFeature x11
+" Test if socket server, X11, and mswin backends can be chosen and work properly.
+func Test_client_server_multiple_backends()
+    CheckFeature socketserver
 
-  let g:test_is_flaky = 1
-  let cmd = GetVimCommand()
+    let g:test_is_flaky = 1
+    let cmd = GetVimCommand()
 
-  if cmd == ''
-    throw 'GetVimCommand() failed'
-  endif
-  call Check_X11_Connection()
-
-  let types = ['socket', 'x11']
-
-  for type in types
-    let name = 'VIMTEST_' .. toupper(type)
-    let actual_cmd = cmd .. ' --clientserver ' .. type
-    let actual_cmd .= ' --servername ' .. name
-    let job = job_start(actual_cmd, {'stoponexit': 'kill', 'out_io': 'null'})
-
-    call WaitForAssert({-> assert_equal("run", job_status(job))})
-    call WaitForAssert({-> assert_match(name, system(cmd .. ' --clientserver ' .. type .. ' --serverlist'))})
-
-    call assert_match(name, system(actual_cmd .. ' --remote-expr "v:servername"'))
-
-    call system(actual_cmd .. " --remote-expr 'execute(\"qa!\")'")
-    try
-      call WaitForAssert({-> assert_equal("dead", job_status(job))})
-    finally
-      if job_status(job) != 'dead'
-        call assert_report('Server did not exit')
-        call job_stop(job, 'kill')
-      endif
-    endtry
-  endfor
-endfunc
-
-" Test if socket server works in the GUI
-func Test_client_server_socket_server_gui()
-  CheckNotMSWindows
-  CheckFeature socketserver
-  CheckFeature gui_gtk
-
-  let g:test_is_flaky = 1
-  let cmd = GetVimCommand()
-
-  if cmd == ''
-    throw 'GetVimCommand() failed'
-  endif
-  call Check_X11_Connection()
-
-  let name = 'VIMTESTSOCKET'
-  let cmd .= ' --clientserver socket'
-  let cmd .= ' --servername ' .. name
-
-  let job = job_start(cmd, {'stoponexit': 'kill', 'out_io': 'null'})
-
-  call WaitForAssert({-> assert_equal("run", job_status(job))})
-  call WaitForAssert({-> assert_match(name, system(cmd .. ' --serverlist'))})
-
-  call system(cmd .. " --remote-expr 'execute(\"gui\")'")
-
-  call assert_match('1', system(cmd .. " --remote-expr 'has(\"gui_running\")'"))
-  call assert_match(name, system(cmd .. ' --remote-expr "v:servername"'))
-
-  call system(cmd .. " --remote-expr 'execute(\"qa!\")'")
-  try
-    call WaitForAssert({-> assert_equal("dead", job_status(job))})
-  finally
-    if job_status(job) != 'dead'
-      call assert_report('Server did not exit')
-      call job_stop(job, 'kill')
+    if cmd == ''
+      throw 'GetVimCommand() failed'
     endif
-  endtry
-endfunc
+    call Check_X11_Connection()
+
+    let types = [
+          \ ['socket', "channel:2000"],
+          \ ['x11', "TEST"],
+          \ ['mswin', "TEST"],
+          \ ]
+
+    for [type, expected] in types
+      if (type == 'x11' && (!has('x11') || !empty($WAYLAND_DISPLAY) || empty($DISPLAY))
+            \ || (type == 'mswin' && !has('win32')))
+        continue
+      endif
+      if has('win32') && has('gui_running')
+        " Windows gVim --remote-expr shows a dialog window, which blocks tests
+        " from running. Using --gui-dialog-file does not seem to work either.
+        continue
+      endif
+
+      let actual_cmd = cmd .. ' --clientserver ' .. type
+      let actual_cmd ..= ' --servername ' .. expected
+      let job = job_start(actual_cmd, {'stoponexit': 'kill', 'out_io': 'null'})
+
+      call WaitForAssert({-> assert_equal("run", job_status(job))})
+      call assert_match(expected, system(actual_cmd .. ' --remote-expr "v:servername"'))
+
+      " On Windows using --remote-expr causes E282, possibly due to some shell
+      " escaping quirk? When gtk gui is running, using system() seems to cause a
+      " deadlock when using the x11 backend only... don't use it for now...
+      if has('win32') || has('gui_running')
+        call job_stop(job, 'kill')
+      else
+        call system(actual_cmd .. " --remote-expr 'execute(\"qa!\")'")
+      endif
+      try
+        call WaitForAssert({-> assert_equal("dead", job_status(job))})
+      finally
+        if job_status(job) != 'dead'
+          call assert_report('Server did not exit')
+          call job_stop(job, 'kill')
+        endif
+      endtry
+    endfor
+  endfunc
 
 " Test if custom paths work for socketserver
-func Test_client_socket_server_custom_path()
-  CheckNotMSWindows
+func Test_client_server_socketserver_custom_path()
   CheckFeature socketserver
-  CheckNotFeature x11
+  CheckNotMSWindows
 
   let g:test_is_flaky = 1
   let cmd = GetVimCommand()
@@ -342,7 +315,7 @@ func Test_client_socket_server_custom_path()
   let paths = ['./' .. name, '../testdir/' .. name, getcwd(-1) .. '/' .. name]
 
   for path in paths
-    let actual = cmd .. ' --servername ' .. path
+    let actual = cmd .. ' --clientserver socket --servername ' .. path
 
     let job = job_start(actual, {'stoponexit': 'kill', 'out_io': 'null'})
 
@@ -361,6 +334,170 @@ func Test_client_socket_server_custom_path()
   endfor
 endfunc
 
+" Test if "channel:" prefix works correctly to use channel address for
+" socketserver.
+func Test_client_server_socketserver_address()
+  CheckFeature socketserver
+
+  let g:test_is_flaky = 1
+  let cmd = GetVimCommand()
+
+  if cmd == ''
+    throw 'GetVimCommand() failed'
+  endif
+
+  let actual = cmd .. ' --clientserver socket --servername channel:2000'
+
+  let job = job_start(actual, {'stoponexit': 'kill', 'out_io': 'null'})
+
+  call WaitForAssert({-> assert_equal("run", job_status(job))})
+
+  if !has('win32') || !has('gui_running')
+    " Does not work with gVim on Windows because it shows an OK dialog box which
+    " blocks tests from running
+      call assert_match('channel:2000', system(actual .. ' --remote-expr "v:servername"'))
+  endif
+
+  if has('win32')
+    call job_stop(job, 'kill')
+  else
+    call system(actual .. " --remote-expr 'execute(\"qa!\")'")
+  endif
+  try
+    call WaitForAssert({-> assert_equal("dead", job_status(job))})
+  finally
+    if job_status(job) != 'dead'
+      call assert_report('Server did not exit')
+      call job_stop(job, 'kill')
+    endif
+  endtry
+endfunc
+
+" Test if --remote-wait works properly with multiple files
+func Test_client_server_multiple_remote_wait()
+  CheckRunVimInTerminal
+
+  call Check_X11_Connection()
+
+  let buf = RunVimInTerminal('--servername TEST', {'rows': 8})
+  call TermWait(buf)
+
+  call writefile(["1"], 'XRemoteOne', 'D')
+  call writefile(["2"], 'XRemoteTwo', 'D')
+
+  let cmd = GetVimCommand()
+
+  if cmd == ''
+    throw 'GetVimCommand() failed'
+  endif
+
+  let actual = cmd .. ' -n --servername TEST  --remote-wait ./XRemoteOne ./XRemoteTwo'
+  let job = job_start(actual, {'stoponexit': 'kill', 'out_io': 'null'})
+
+  sleep 500m " Wait for server to receive request
+  call assert_equal("run", job_status(job))
+
+  call term_sendkeys(buf, "\<Esc>:next\<CR>")
+  call TermWait(buf)
+  call assert_equal("run", job_status(job))
+
+  call term_sendkeys(buf, "\<Esc>:q!\<CR>") " Don't use qa! because we only want to quit one file
+  call WaitForAssert({-> assert_equal("dead", job_status(job))})
+endfunc
+
+" Check if socket is removed even if Vim changes directory
+func Test_client_server_socketserver_chdir()
+  CheckFeature socketserver
+  CheckRunVimInTerminal
+  CheckNotMSWindows
+
+  let buf = RunVimInTerminal('--clientserver socket --servername ./TEST',
+        \ {'rows': 8})
+  call TermWait(buf)
+
+  call term_sendkeys(buf, "\<Esc>:cd ../\<CR>")
+  call StopVimInTerminal(buf)
+
+  call assert_equal("", glob("./TEST"))
+endfunc
+
+func DummyServerCallback(ch, addr)
+  let msg = json_encode(#{type: "ver"}) .. "\n"
+  call ch_sendraw(a:ch, msg)
+endfunc
+
+" Test if commands with different version are ignored and handled properly.
+func Test_client_server_socketserver_version_mismatch()
+  CheckFeature socketserver
+  CheckRunVimInTerminal
+  CheckScreendump
+
+  let cmd = GetVimCommand()
+
+  if cmd == ''
+    throw 'GetVimCommand() failed'
+  endif
+
+  let buf = RunVimInTerminal('--clientserver socket --servername
+        \ channel:2000', {'rows': 8})
+  call TermWait(buf)
+
+  let ch = ch_open('localhost:2000', #{mode: 'nl'})
+  let msg = json_encode(#{
+        \ type: "expr",
+        \ str: "v:servername",
+        \ version: 999999999
+        \ }) .. "\n"
+
+  call ch_sendraw(ch, msg)
+  let resp = ch_readraw(ch)
+
+  call assert_equal(#{type: "ver"}, json_decode(resp))
+
+  call StopVimInTerminal(buf)
+
+  let ch = ch_listen("2000", #{
+        \ mode: 'nl',
+        \ callback: function('DummyServerCallback')
+        \ })
+
+  let buf = RunVimInTerminal('--clientserver socket --servername channel:3000', {'rows': 8})
+  call TermWait(buf)
+
+  call term_sendkeys(buf, "\<Esc>:echo remote_expr('channel:2000', 'v:servername', '', 1)\<CR>")
+  call TermWait(buf)
+
+  call VerifyScreenDump(buf, 'Test_clientserver_1', #{wait: 3000})
+
+  call StopVimInTerminal(buf)
+endfunc
+
+" Test if invalid messages do not crash Vim socketserver.
+func Test_clientserver_socketserver_invalid_msg()
+  CheckFeature socketserver
+  CheckRunVimInTerminal
+
+  let cmd = GetVimCommand()
+
+  if cmd == ''
+    throw 'GetVimCommand() failed'
+  endif
+
+  let buf = RunVimInTerminal('--clientserver socket --servername
+        \ channel:3000', {'rows': 8})
+  call TermWait(buf)
+
+  let ch = ch_open('localhost:3000', #{mode: 'nl'})
+
+  call ch_sendraw(ch, "wjdaljdsjalsj\n")
+  call ch_sendraw(ch, "{\"type\": \"unknown\"}\n")
+
+  call assert_match("channel:3000", system(cmd .. " --clientserver socket --servername channel:3000 --remote-expr 'v:servername'"))
+  call assert_equal("running", term_getstatus(buf))
+
+  call StopVimInTerminal(buf)
+endfunc
+
 " Uncomment this line to get a debugging log
 " call ch_logfile('channellog', 'w')
 

src/testdir/test_remote.vim

@@ -16,18 +16,6 @@ func Verify_remote_feature_works()
   let buf = RunVimInTerminal('--servername XVIMTEST', {'rows': 8})
   call TermWait(buf)
 
-  " For some reason when the socket server is being used, the terminal Vim never
-  " receives the `:w! XVimRemoteTest.txt` command from term_sendkeys.
-  if has('socketserver') && !has('X11')
-    if match(serverlist(), "XVIMTEST") == -1
-      call StopVimInTerminal(buf)
-      throw s:skip
-    endif
-
-    let s:remote = 1
-    return
-  endif
-
   let cmd = GetVimCommandCleanTerm() .. '--serverlist'
   call term_sendkeys(buf, ":r! " .. cmd .. "\<CR>")
   call TermWait(buf)
@@ -71,6 +59,14 @@ func Test_remote_servername()
   " open XTEST.txt, if wildignore setting is not ignored, the server
   " will continue with the Xdummy.log file
   let buf2 = RunVimInTerminal('--servername XVIMTEST --remote-silent XTEST.txt', {'rows': 5, 'wait_for_ruler': 0})
+
+  " It may take a while for the command to be sent to XVIMTEST and be executed.
+  " Do a blocking --remote-expr so that is assured the command was executed.
+  botright new
+  let buf3 = RunVimInTerminal('--servername XVIMTEST --remote-expr "v:servername"', {'rows': 5, 'wait_for_ruler': 0})
+  call WaitForAssert({-> assert_equal("finished", term_getstatus(buf3))})
+  exe buf3 .. 'bw!'
+
   " job should be no-longer running, so we can just close it
   exe buf2 .. 'bw!'
   call term_sendkeys(buf, ":sil :3,$d\<CR>")

src/testdir/test_usercommands.vim

@@ -402,7 +402,6 @@ func Test_CmdCompletion()
     exe 'delcommand ' .. cmd
   endfor
   delcommand MissingFeature
-  delcommand RunSocketServer
 
   command! DoCmd1 :
   command! DoCmd2 :

src/testdir/test_vim9_builtin.vim

@@ -1,7 +1,6 @@
 " Test using builtin functions in the Vim9 script language.
 
 source util/screendump.vim
-source util/socketserver.vim
 import './util/vim9.vim' as v9
 
 " Test for passing too many or too few arguments to builtin functions
@@ -3525,11 +3524,12 @@ enddef
 
 def Test_remote_expr()
   CheckFeature clientserver
-  TrySocketServer
+  CheckNotMSWindows
 
-  if !g:socketserver_only
+  if has("x11")
     CheckEnv DISPLAY
   endif
+
   v9.CheckSourceDefAndScriptFailure(['remote_expr(1, "b")'], ['E1013: Argument 1: type mismatch, expected string but got number', 'E1174: String required for argument 1'])
   v9.CheckSourceDefAndScriptFailure(['remote_expr("a", 2)'], ['E1013: Argument 2: type mismatch, expected string but got number', 'E1174: String required for argument 2'])
   v9.CheckSourceDefAndScriptFailure(['remote_expr("a", "b", 3)'], ['E1013: Argument 3: type mismatch, expected string but got number', 'E1174: String required for argument 3'])
@@ -3551,10 +3551,12 @@ enddef
 
 def Test_remote_peek()
   CheckFeature clientserver
-  TrySocketServer
-  if !g:socketserver_only
+  CheckNotMSWindows
+
+  if has("x11")
     CheckEnv DISPLAY
   endif
+
   v9.CheckSourceDefAndScriptFailure(['remote_peek(0z10)'], ['E1013: Argument 1: type mismatch, expected string but got blob', 'E1174: String required for argument 1'])
   v9.CheckSourceDefAndScriptFailure(['remote_peek("a5b6c7", [1])'], ['E1013: Argument 2: type mismatch, expected string but got list<number>', 'E1174: String required for argument 2'])
   v9.CheckSourceDefExecAndScriptFailure(['remote_peek("")'], 'E573: Invalid server id used')
@@ -3562,7 +3564,12 @@ enddef
 
 def Test_remote_read()
   CheckFeature clientserver
-  CheckEnv DISPLAY
+  CheckNotMSWindows
+
+  if has("x11")
+    CheckEnv DISPLAY
+  endif
+
   v9.CheckSourceDefAndScriptFailure(['remote_read(1)'], ['E1013: Argument 1: type mismatch, expected string but got number', 'E1174: String required for argument 1'])
   v9.CheckSourceDefAndScriptFailure(['remote_read("a", "x")'], ['E1013: Argument 2: type mismatch, expected number but got string', 'E1210: Number required for argument 2'])
   v9.CheckSourceDefExecAndScriptFailure(['remote_read("")'], 'E573: Invalid server id used')
@@ -3570,10 +3577,12 @@ enddef
 
 def Test_remote_send()
   CheckFeature clientserver
-  TrySocketServer
-  if !g:socketserver_only
+  CheckNotMSWindows
+
+  if has("x11")
     CheckEnv DISPLAY
   endif
+
   v9.CheckSourceDefAndScriptFailure(['remote_send(1, "b")'], ['E1013: Argument 1: type mismatch, expected string but got number', 'E1174: String required for argument 1'])
   v9.CheckSourceDefAndScriptFailure(['remote_send("a", 2)'], ['E1013: Argument 2: type mismatch, expected string but got number', 'E1174: String required for argument 2'])
   v9.CheckSourceDefAndScriptFailure(['remote_send("a", "b", 3)'], ['E1013: Argument 3: type mismatch, expected string but got number', 'E1174: String required for argument 3'])
@@ -3582,10 +3591,12 @@ enddef
 
 def Test_remote_startserver()
   CheckFeature clientserver
-  TrySocketServer
-  if !g:socketserver_only
+  CheckNotMSWindows
+
+  if has("x11")
     CheckEnv DISPLAY
   endif
+
   v9.CheckSourceDefAndScriptFailure(['remote_startserver({})'], ['E1013: Argument 1: type mismatch, expected string but got dict<any>', 'E1174: String required for argument 1'])
 enddef
 

src/testdir/util/check.vim

@@ -348,17 +348,6 @@ func CheckGithubActions()
   endif
 endfunc
 
-command RunSocketServer call RunSocketServer()
-func RunSocketServer()
-  if has("socketserver") && v:servername == ""
-    try
-      call remote_startserver('VIMSOCKETSERVERTEST')
-    catch " not possible to start a remote server
-      throw 'Skipped: Cannot start remote server'
-    endtry
-  endif
-endfunc
-
 let &cpo = s:cpo_save
 unlet s:cpo_save
 " vim: shiftwidth=2 sts=2 expandtab

src/testdir/util/socketserver.vim

@@ -1,17 +0,0 @@
-" Check if only the socketserver backend is available for clientserver (only on
-" Unix), and set g:socketserver_only to v:true along with starting the
-" socketserver.
-command TrySocketServer call TrySocketServer()
-func TrySocketServer()
-  if has("socketserver") && !has("x11")
-    let g:socketserver_only = v:true
-
-    if v:servername == ""
-      call remote_startserver('VIMSOCKETSERVERTEST')
-    endif
-  else
-      let g:socketserver_only = v:false
-    endif
-endfunc
-
-" vim: shiftwidth=2 sts=2 expandtab

src/ui.c

@@ -406,20 +406,10 @@ inchar_loop(
 # endif
 
 	if ((resize_func != NULL && resize_func(TRUE))
-# if defined(FEAT_CLIENTSERVER) && defined(UNIX)
-		|| (
-#  ifdef FEAT_X11
-		    (clientserver_method == CLIENTSERVER_METHOD_X11 &&
-		    server_waiting())
-#  endif
-#  if defined(FEAT_X11) && defined(FEAT_SOCKETSERVER)
-		    ||
-#  endif
-#  ifdef FEAT_SOCKETSERVER
-		    (clientserver_method == CLIENTSERVER_METHOD_SOCKET &&
-		     socket_server_waiting_accept())
-#  endif
-		)
+# if defined(FEAT_CLIENTSERVER) && defined(FEAT_X11)
+		||
+		(clientserver_method == CLIENTSERVER_METHOD_X11 &&
+		 server_waiting())
 # endif
 # ifdef MESSAGE_QUEUE
 		|| interrupted

src/version.c

@@ -729,6 +729,8 @@ static char *(features[]) =
 
 static int included_patches[] =
 {   /* Add new patch number below this line */
+/**/
+    512,
 /**/
     511,
 /**/