Bump version, update NEWS

Additional lines might have been passed to the server intact
as part of an argument, but we have /quote for that.

LICENSE

@@ -1,4 +1,4 @@
-Copyright (c) 2014 - 2023, Přemysl Eric Janouch <p@janouch.name>
+Copyright (c) 2014 - 2024, Přemysl Eric Janouch <p@janouch.name>
 
 Permission to use, copy, modify, and/or distribute this software for any
 purpose with or without fee is hereby granted.

NEWS

@@ -1,4 +1,4 @@
-2.0.0 (Unreleased)
+2.0.0 (2024-07-28) "Perfect Is the Enemy of Good"
 
  * xD: now using SHA-256 for client certificate fingerprints
 
@@ -16,6 +16,8 @@
 
  * xC: replaced behaviour.save_on_quit with general.autosave
 
+ * xC: the server *.command configuration option now supports multiple lines
+
  * xC: improved pager integration capabilities
 
  * xC: unsolicited JOINs will no longer automatically activate the buffer
@@ -33,8 +35,12 @@
 
  * Added a Win32 frontend for xC called xW
 
+ * Added a Cocoa frontend for xC called xM
+
  * Added a Go port of xD called xS
 
+ * Added a simple notifier called xN
+
 
 1.5.0 (2021-12-21) "The Show Must Go On"
 

README.adoc

@@ -1,9 +1,10 @@
 xK
 ==
 
-'xK' (chat kit) is an IRC software suite consisting of a daemon, bot, terminal
+'xK' (chat kit) is an IRC software suite consisting of a daemon, bot, notifier,
-client, and web + Win32 frontends for the client.  It's all you're ever going to
+terminal client, and web/Windows/macOS frontends for the client.  It's all
-need for chatting, so long as you can make do with slightly minimalist software.
+you're ever going to need for chatting, so long as you can make do with slightly
+minimalist software.
 
 They're all lean on dependencies, and offer a maximally permissive licence.
 
@@ -55,6 +56,10 @@ https://github.com/kiwiirc/webircgateway[].
 Any further development, such as P10 or TS6 linking for IRC services,
 or plugin support for arbitrary bridges, will happen here.
 
+xN
+--
+The IRC notifier, should you ever need to send automated messages from a script.
+
 xB
 --
 The IRC bot.  While originally intended to be a simple rewrite of my old GNU AWK
@@ -140,13 +145,23 @@ endpoint as the third command line argument in this case.
 xW
 ~~
 The Win32 frontend is a separate CMake subproject that should be compiled
-using MinGW-w64.  In order to run it, make a shortcut for the executable and
+using MinGW-w64.  To avoid having to specify the relay address each time you
-include the relay address in its _Target_ field:
+run it, create a shortcut for the executable and include the address in its
+_Target_ field:
 
  C:\...\xW.exe 127.0.0.1 9000
 
 It works reasonably well starting with Windows 7.
 
+xM
+~~
+The Cocoa frontend is a separate CMake subproject that requires Xcode to build.
+It is currently not that usable.  The relay address can either be passed on
+the command line, or preset in the _defaults_ database:
+
+ $ defaults write name.janouch.xM relayHost 127.0.0.1
+ $ defaults write name.janouch.xM relayPort 9000
+
 Client Certificates
 -------------------
 'xC' will use the SASL EXTERNAL method to authenticate using the TLS client

xC.c

@@ -1,7 +1,7 @@
 /*
  * xC.c: a terminal-based IRC client
  *
- * Copyright (c) 2015 - 2022, Přemysl Eric Janouch <p@janouch.name>
+ * Copyright (c) 2015 - 2024, Přemysl Eric Janouch <p@janouch.name>
  *
  * Permission to use, copy, modify, and/or distribute this software for any
  * purpose with or without fee is hereby granted.
@@ -8317,6 +8317,8 @@ irc_try_parse_welcome_for_userhost (struct server *s, const char *m)
 	strv_free (&v);
 }
 
+static void process_input
+	(struct app_context *, struct buffer *, const char *);
 static bool process_input_line
 	(struct app_context *, struct buffer *, const char *, int);
 static void on_autoaway_timer (struct app_context *ctx);
@@ -8345,7 +8347,7 @@ irc_on_registered (struct server *s, const char *nickname)
 	if (command)
 	{
 		log_server_debug (s, "Executing \"#s\"", command);
-		(void) process_input_line (s->ctx, s->buffer, command, 0);
+		(void) process_input (s->ctx, s->buffer, command);
 	}
 
 	int64_t command_delay = get_config_integer (s->config, "command_delay");
@@ -9439,6 +9441,9 @@ server_add (struct app_context *ctx,
 	str_map_set (&ctx->servers, s->name, s);
 	s->config = subtree;
 
+	relay_prepare_server_update (ctx, s);
+	relay_broadcast (ctx);
+
 	// Add a buffer and activate it
 	struct buffer *buffer = s->buffer = buffer_new (ctx->input,
 		BUFFER_SERVER, irc_make_buffer_name (s, NULL));
@@ -12937,6 +12942,16 @@ handle_command_kill (struct handler_args *a)
 	return true;
 }
 
+static bool
+handle_command_away (struct handler_args *a)
+{
+	if (*a->arguments)
+		irc_send (a->s, "AWAY :%s", a->arguments);
+	else
+		irc_send (a->s, "AWAY");
+	return true;
+}
+
 static bool
 handle_command_nick (struct handler_args *a)
 {
@@ -13002,7 +13017,6 @@ TRIVIAL_HANDLER (who,   "WHO")
 TRIVIAL_HANDLER (motd,  "MOTD")
 TRIVIAL_HANDLER (oper,  "OPER")
 TRIVIAL_HANDLER (stats, "STATS")
-TRIVIAL_HANDLER (away,  "AWAY")
 
 // - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
 
@@ -15543,14 +15557,13 @@ static void
 client_process_buffer_log
 	(struct client *c, uint32_t seq, struct buffer *buffer)
 {
-	struct relay_event_data_response *e = relay_prepare_response (c->ctx, seq);
+	// XXX: We log failures to the global buffer,
-	e->data.command = RELAY_COMMAND_BUFFER_LOG;
+	//   so the client just receives nothing if there is no log file.
-
+	struct str log = str_make ();
 	char *path = buffer_get_log_path (buffer);
 	FILE *fp = open_log_path (c->ctx, buffer, path);
 	if (fp)
 	{
-		struct str log = str_make ();
 		char buf[BUFSIZ];
 		size_t len;
 		while ((len = fread (buf, 1, sizeof buf, fp)))
@@ -15558,17 +15571,15 @@ client_process_buffer_log
 		if (ferror (fp))
 			log_global_error (c->ctx, "Failed to read `#l': #l",
 				path, strerror (errno));
-
-		// On overflow, it will later fail serialization.
-		e->data.buffer_log.log_len = MIN (UINT32_MAX, log.len);
-		e->data.buffer_log.log = (uint8_t *) str_steal (&log);
 		fclose (fp);
 	}
-
-	// XXX: We log failures to the global buffer,
-	//   so the client just receives nothing if there is no log file.
-
 	free (path);
+
+	struct relay_event_data_response *e = relay_prepare_response (c->ctx, seq);
+	e->data.command = RELAY_COMMAND_BUFFER_LOG;
+	// On overflow, it will later fail serialization (frame will be too long).
+	e->data.buffer_log.log_len = MIN (UINT32_MAX, log.len);
+	e->data.buffer_log.log = (uint8_t *) str_steal (&log);
 	relay_send (c);
 }
 
@@ -15856,6 +15867,7 @@ relay_start (struct app_context *ctx, char *address, struct error **e)
 	}
 
 	// Just try the first one, disregarding IPv4/IPv6 ordering.
+	// Use 0.0.0.0 or [::] to request either one specifically.
 	int fd = relay_listen_with_context (ctx, result, e);
 	freeaddrinfo (result);
 	if (fd == -1)

xK-version

@@ -1 +1 @@
-1.5.0
+2.0.0

xM/CMakeLists.txt

@@ -0,0 +1,45 @@
+# Swift language support
+cmake_minimum_required (VERSION 3.15)
+
+file (READ ../xK-version project_version)
+configure_file (../xK-version xK-version.tag COPYONLY)
+string (STRIP "${project_version}" project_version)
+
+# There were two issues when building this from the main CMakeLists.txt:
+# a) renaming main.swift to xM.swift requires removing top-level statements,
+# b) there is a "redefinition of module 'FFI'" error.
+project (xM VERSION "${project_version}"
+	DESCRIPTION "Cocoa frontend for xC" LANGUAGES Swift)
+
+set (root "${PROJECT_SOURCE_DIR}/..")
+add_custom_command (OUTPUT xC-proto.swift
+	COMMAND env LC_ALL=C awk
+		-f ${root}/liberty/tools/lxdrgen.awk
+		-f ${root}/liberty/tools/lxdrgen-swift.awk
+		-v PrefixCamel=Relay
+		${root}/xC.lxdr > xC-proto.swift
+	DEPENDS
+		${root}/liberty/tools/lxdrgen.awk
+		${root}/liberty/tools/lxdrgen-swift.awk
+		${root}/xC.lxdr
+	COMMENT "Generating xC relay protocol code" VERBATIM)
+
+set (MACOSX_BUNDLE_GUI_IDENTIFIER name.janouch.${PROJECT_NAME})
+set (MACOSX_BUNDLE_ICON_FILE xM.icns)
+
+# Avoid including binary files in the repository by generating icons in code.
+# sips(1) + Javascript + iconutil(1) could probably also be used.
+find_program (SWIFT_EXECUTABLE swift REQUIRED)
+
+set (icon "${PROJECT_BINARY_DIR}/${MACOSX_BUNDLE_ICON_FILE}")
+add_custom_command (OUTPUT "${icon}"
+	COMMAND ${SWIFT_EXECUTABLE} "${PROJECT_SOURCE_DIR}/gen-icon.swift" "${icon}"
+	DEPENDS gen-icon.swift
+	COMMENT "Generating xM application icon" VERBATIM)
+set_source_files_properties ("${icon}" PROPERTIES
+	MACOSX_PACKAGE_LOCATION Resources)
+
+# Other requirements: macOS 10.14 for Network, and macOS 11 for Logger.
+set (CMAKE_Swift_LANGUAGE_VERSION 5)
+add_executable (xM MACOSX_BUNDLE
+	main.swift "${icon}" "${PROJECT_BINARY_DIR}/xC-proto.swift")

xM/gen-icon.swift

@@ -0,0 +1,96 @@
+// gen-icon.swift: generate a program icon for xM in the Apple icon format
+//
+// Copyright (c) 2023, Přemysl Eric Janouch <p@janouch.name>
+// SPDX-License-Identifier: 0BSD
+//
+// NSGraphicsContext mostly just weirdly wraps over Quartz,
+// so we do it all in Quartz directly.
+import CoreGraphics
+import Foundation
+import ImageIO
+import UniformTypeIdentifiers
+
+// Apple uses something that's close to a "quintic superellipse" in their icons,
+// but doesn't quite match. Either way, it looks better than rounded rectangles.
+func addSquircle(context: CGContext, bounds: CGRect) {
+	context.move(to: CGPoint(x: bounds.maxX, y: bounds.midY))
+	for theta in stride(from: 0.0, to: .pi * 2, by: .pi / 1e4) {
+		let x = pow(abs(cos(theta)), 2 / 5.0) * bounds.width / 2
+			* CGFloat(signOf: cos(theta), magnitudeOf: 1) + bounds.midX
+		let y = pow(abs(sin(theta)), 2 / 5.0) * bounds.height / 2
+			* CGFloat(signOf: sin(theta), magnitudeOf: 1) + bounds.midY
+		context.addLine(to: CGPoint(x: x, y: y))
+	}
+	context.closePath()
+}
+
+func drawIcon(scale: CGFloat) -> CGImage? {
+	let size = CGSizeMake(1024, 1024)
+
+	let colorspace = CGColorSpaceCreateDeviceRGB()
+	let context = CGContext(data: nil,
+		width: Int(size.width * scale), height: Int(size.height * scale),
+		bitsPerComponent: 8, bytesPerRow: 0, space: colorspace,
+		bitmapInfo: CGImageAlphaInfo.premultipliedLast.rawValue)!
+	context.scaleBy(x: scale, y: scale)
+
+	let bounds = CGRectMake(100, 100, size.width - 200, size.height - 200)
+	addSquircle(context: context, bounds: bounds)
+	let squircle = context.path!
+
+	// Gradients don't draw shadows, so draw it separately.
+	context.saveGState()
+	context.setShadow(offset: CGSizeMake(0, -12).applying(context.ctm),
+		blur: 28 * scale, color: CGColor(gray: 0, alpha: 0.5))
+	context.setFillColor(CGColor(red: 1, green: 0x55p-8, blue: 0, alpha: 1))
+	context.fillPath()
+	context.restoreGState()
+
+	context.saveGState()
+	context.addPath(squircle)
+	context.clip()
+	context.drawLinearGradient(
+		CGGradient(colorsSpace: colorspace, colors: [
+			CGColor(red: 1, green: 0x00p-8, blue: 0, alpha: 1),
+			CGColor(red: 1, green: 0xaap-8, blue: 0, alpha: 1)
+		] as CFArray, locations: [0, 1])!,
+		start: CGPointMake(0, 100), end: CGPointMake(0, size.height - 100),
+		options: CGGradientDrawingOptions(rawValue: 0))
+	context.restoreGState()
+
+	context.move(to: CGPoint(x: size.width * 0.30, y: size.height * 0.30))
+	context.addLine(to: CGPoint(x: size.width * 0.30, y: size.height * 0.70))
+	context.addLine(to: CGPoint(x: size.width * 0.575, y: size.height * 0.425))
+	context.move(to: CGPoint(x: size.width * 0.70, y: size.height * 0.30))
+	context.addLine(to: CGPoint(x: size.width * 0.70, y: size.height * 0.70))
+	context.addLine(to: CGPoint(x: size.width * 0.425, y: size.height * 0.425))
+	context.setLineWidth(80)
+	context.setLineCap(.round)
+	context.setLineJoin(.round)
+	context.setStrokeColor(CGColor.white)
+	context.strokePath()
+	return context.makeImage()
+}
+
+if CommandLine.arguments.count != 2 {
+	print("Usage: \(CommandLine.arguments.first!) OUTPUT.icns")
+	exit(EXIT_FAILURE)
+}
+
+let filename = CommandLine.arguments[1]
+
+let macOSSizes: Array<CGFloat> = [16, 32, 128, 256, 512]
+let icns = CGImageDestinationCreateWithURL(
+	URL(fileURLWithPath: filename) as CFURL,
+	UTType.icns.identifier as CFString, macOSSizes.count * 2, nil)!
+for size in macOSSizes {
+	CGImageDestinationAddImage(icns, drawIcon(scale: size / 1024.0)!, nil)
+	CGImageDestinationAddImage(icns, drawIcon(scale: size / 1024.0 * 2)!, [
+			kCGImagePropertyDPIWidth: 144,
+			kCGImagePropertyDPIHeight: 144,
+		] as CFDictionary)
+}
+if !CGImageDestinationFinalize(icns) {
+	print("ICNS finalization failed.")
+	exit(EXIT_FAILURE)
+}

xN/.gitignore

@@ -0,0 +1,3 @@
+/xN
+/xN.1
+/irc.go

xN/Makefile

@@ -0,0 +1,21 @@
+.POSIX:
+.SUFFIXES:
+AWK = env LC_ALL=C awk
+
+outputs = irc.go xN xN.1
+all: $(outputs)
+
+# If we want to keep module dependencies separate, we don't have many options.
+# Symlinking seems to work good enough.
+irc.go: ../xS/irc.go
+	ln -sf ../xS/irc.go $@
+
+xN: xN.go ../xK-version irc.go
+	go build -ldflags "-X 'main.projectVersion=$$(cat ../xK-version)'" -o $@
+xN.1: ../xK-version ../liberty/tools/asciiman.awk xN.adoc
+	env "asciidoc-release-version=$$(cat ../xK-version)" \
+		$(AWK) -f ../liberty/tools/asciiman.awk xN.adoc > $@
+test: all
+	go test
+clean:
+	rm -f $(outputs)

xN/go.mod

@@ -0,0 +1,3 @@
+module janouch.name/xK/xN
+
+go 1.19

xN/xN.adoc

@@ -0,0 +1,86 @@
+xN(1)
+=====
+:doctype: manpage
+:manmanual: xK Manual
+:mansource: xK {release-version}
+
+Name
+----
+xN - IRC notifier
+
+Synopsis
+--------
+*xN* [_OPTION_]... IRC-URL...
+
+Description
+-----------
+*xN* is a simple IRC notifier, sending the text it receives on its standard
+input to all IRC targets specified by its command line arguments.
+
+The input text is forced to validate as UTF-8, and it is _not_ split
+automatically to comply with the maximum IRC message length.
+Thus, make sure to make the lines short, or they will be trimmed by the servers.
+
+*xN* does not attempt to appease flood detectors.
+
+Options
+-------
+*-debug*::
+	Print incoming IRC traffic, which may help in debugging any issues.
+
+*-version*::
+	Output version information and exit.
+
+URL format
+----------
+*xN* accepts URLs describing IRC users and channels, roughly as specified by
+the Internet Draft _draft-butcher-irc-url-04.txt_.  Note, however, that close
+to no validation is done on these, and you should not pass URLs from untrusted
+sources, so as to avoid command or parameter injection.
+
+Any provided username will be propagated to the nickname, username,
+and realname.  The default value for these is the name of your system user.
+
+As an extension, you may use the following options:
+
+*skipjoin*::
+	Do not JOIN channels before sending messages to them.
+	This requires channels to allow external messages
+	(which are disabled by channel mode *+n*).
+*usenotice*::
+	Send a NOTICE rather than a PRIVMSG, which distinguishes automated messages,
+	and is more appropriate for bots.
+
+Examples
+--------
+ $ uptime | xN 'irc://uptime@localhost/%23watch?skipjoin&usenotice'
+
+Send *uptime*(1) information as an external notice to channel *#watch*
+on the local server, using the standard port *6667*.
+
+ $ fortune -s | xN ircs://ohayou@irc.libera.chat/john,isuser
+
+Greet user *john* with a fortune for this day.  In compliance with _RFC 7194_,
+the default TLS port is assumed to be *6697*.
+
+ $ xN 'ircs://agent:Password123@irc.cia.gov:1337/#hq?key=123456' <<EOF
+ The red fox trots quietly at midnight.
+ EOF
+
+Connect over TLS to *irc.cia.gov* on port *1337*, use *Password123*
+as the server password, register as user *agent*,
+join channel *#hq* using the channel key *123456*,
+and send a very secret message.
+
+Reporting bugs
+--------------
+Use https://git.janouch.name/p/xK to report bugs, request features,
+or submit pull requests.
+
+See also
+--------
+_Uniform Resource Locator Schemes for Internet Relay Chat Entities_,
+https://datatracker.ietf.org/doc/html/draft-butcher-irc-url-04[].
+
+_Default Port for Internet Relay Chat (IRC) via TLS/SSL_,
+https://datatracker.ietf.org/doc/html/rfc7194[].

xN/xN.go

@@ -0,0 +1,279 @@
+//
+// Copyright (c) 2024, Přemysl Eric Janouch <p@janouch.name>
+//
+// Permission to use, copy, modify, and/or distribute this software for any
+// purpose with or without fee is hereby granted.
+//
+// THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+// WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
+// MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY
+// SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+// WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION
+// OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN
+// CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+//
+
+// xN is a simple IRC notifier.
+package main
+
+import (
+	"bufio"
+	"bytes"
+	"crypto/tls"
+	"errors"
+	"flag"
+	"fmt"
+	"io"
+	"log"
+	"net"
+	"net/url"
+	"os"
+	"os/user"
+	"strconv"
+	"strings"
+)
+
+const projectName = "xN"
+
+var projectVersion = "?"
+
+var debugMode = false
+
+type parameters struct {
+	conn      net.Conn // underlying network connection
+	username  string   // nickname + username + realname
+	password  string   // server password
+	target    string   // where to send text
+	isuser    bool     // the target is a user rather than a channel
+	chankey   string   // channel key
+	skipjoin  bool     // whether to send external messages to channels
+	usenotice bool     // whether to use NOTICE rather than PRIVMSG
+	message   []string // lines of the message to send
+}
+
+func (p *parameters) send(command string, args ...string) error {
+	var buf bytes.Buffer
+	buf.WriteString(command)
+	for i, arg := range args {
+		buf.WriteRune(' ')
+		if i+1 == len(args) {
+			buf.WriteRune(':')
+		}
+		buf.WriteString(arg)
+	}
+	buf.WriteString("\r\n")
+	_, err := p.conn.Write(buf.Bytes())
+	return err
+}
+
+const (
+	rplWELCOME       = "001"
+	errNICKNAMEINUSE = "433"
+)
+
+func notify(p *parameters) error {
+	// The intro should comfortably fit in the TCP send buffer whole.
+	if p.password != "" {
+		p.send("PASS", p.password)
+	}
+	p.send("USER", p.username, "0", "*", p.username)
+	p.send("NICK", p.username)
+
+	scanner, nickCounter, issue := bufio.NewScanner(p.conn), 1, ""
+	for scanner.Scan() {
+		if debugMode {
+			log.Println(scanner.Text())
+		}
+
+		m := ircParseMessage(scanner.Text())
+		switch m.command {
+		case "PING":
+			p.send("PONG", m.params...)
+		case rplWELCOME:
+			if !p.isuser && !p.skipjoin {
+				if p.chankey != "" {
+					p.send("JOIN", p.target, p.chankey)
+				} else {
+					p.send("JOIN", p.target)
+				}
+			}
+			for _, line := range p.message {
+				if p.usenotice {
+					p.send("NOTICE", p.target, line)
+				} else {
+					p.send("PRIVMSG", p.target, line)
+				}
+			}
+			p.send("QUIT")
+		case errNICKNAMEINUSE:
+			p.send("NICK", fmt.Sprintf("%s%d", p.username, nickCounter))
+			nickCounter++
+		default:
+			// Prevent hanging on unsuccessful registrations.
+			numeric, _ := strconv.Atoi(m.command)
+			if numeric >= 400 && numeric <= 599 {
+				if len(m.params) > 1 {
+					issue = strings.Join(m.params[1:], " ")
+				} else {
+					issue = strings.Join(m.params, " ")
+				}
+				p.send("QUIT")
+			}
+		}
+	}
+	if err := scanner.Err(); err != nil {
+		return err
+	}
+	if issue != "" {
+		return errors.New(issue)
+	}
+	return nil
+}
+
+func parse(rawURL string, text []byte) (
+	p parameters, connect func() (net.Conn, error), err error) {
+	u, err := url.Parse(rawURL)
+	if err != nil {
+		return p, nil, err
+	} else if !u.IsAbs() || u.Opaque != "" {
+		return p, nil, errors.New("need an absolute URL")
+	} else if u.Path == "/" && u.Fragment != "" {
+		// Try to handle the common but degenerate case.
+		fragment := "%23" + u.Fragment
+		u.Fragment, u.RawFragment = "", ""
+		if u, err = url.Parse(u.String() + fragment); err != nil {
+			return p, nil, err
+		}
+	}
+
+	// Figure out registration details.
+	p.username = projectName
+	if u, _ := user.Current(); u != nil {
+		p.username = u.Username
+	}
+	if u.User.Username() != "" {
+		p.username = u.User.Username()
+	}
+
+	p.password, _ = u.User.Password()
+
+	// Figure out the target, which for our intents must accept messages.
+	path, _ := strings.CutPrefix(u.Path, "/")
+	elements := strings.Split(path, ",")
+	if path == "" || elements[0] == "" {
+		return p, nil, errors.New("unspecified entity")
+	}
+
+	// The last entity type wins.
+	p.target, p.isuser = elements[0], false
+	for _, typ := range elements[1:] {
+		switch typ {
+		case "isuser":
+			p.isuser = true
+		case "ischannel":
+			p.isuser = false
+		case "isserver":
+			// We do not support network names, and this is the default.
+		default:
+			return p, nil, errors.New("unsupported type: " + typ)
+		}
+	}
+	if p.isuser {
+		if i := strings.IndexAny(p.target, "!@"); i != -1 {
+			p.target = p.target[:i]
+		}
+	} else if !strings.HasPrefix(p.target, "#") {
+		// TODO(p): We should consult RPL_ISUPPORT rather than guess,
+		// though other prefixes are rare.
+		p.target = "#" + p.target
+	}
+
+	// Note that the draft RFC wants these to be case-insensitive.
+	p.chankey = u.Query().Get("key")
+	// Being able to skip channel join is our own requirement and invention,
+	// as are notices (names taken from Travis CI configuration).
+	p.skipjoin = u.Query().Has("skipjoin")
+	p.usenotice = u.Query().Has("usenotice")
+
+	// Ensure valid LF-separated UTF-8, and split it at lines.
+	sanitized := strings.ReplaceAll(string([]rune(string(text))), "\r", "\n")
+	for _, line := range strings.Split(sanitized, "\n") {
+		if line != "" {
+			p.message = append(p.message, line)
+		}
+	}
+
+	hostname, port := u.Hostname(), u.Port()
+	switch u.Scheme {
+	case "irc":
+		if port == "" {
+			port = "6667"
+		}
+		connect = func() (net.Conn, error) {
+			return net.Dial("tcp", net.JoinHostPort(hostname, port))
+		}
+	case "ircs":
+		if port == "" {
+			port = "6697"
+		}
+		connect = func() (net.Conn, error) {
+			return tls.Dial("tcp", net.JoinHostPort(hostname, port), nil)
+		}
+	default:
+		err = errors.New("unsupported scheme: " + u.Scheme)
+	}
+	return
+}
+
+// notifyByURL sends the given text to the IRC server specified by a URL.
+// See draft-butcher-irc-url-04.txt for the URL scheme specification
+// this function loosely follows.
+func notifyByURL(rawURL string, text []byte) error {
+	p, connect, err := parse(rawURL, text)
+	if p.conn, err = connect(); err != nil {
+		return err
+	}
+	defer p.conn.Close()
+	return notify(&p)
+}
+
+func main() {
+	flag.BoolVar(&debugMode, "debug", false, "run in verbose debug mode")
+	version := flag.Bool("version", false, "show version and exit")
+
+	flag.Usage = func() {
+		f := flag.CommandLine.Output()
+		fmt.Fprintf(f, "Usage: %s [OPTION]... URL...\n", os.Args[0])
+		flag.PrintDefaults()
+	}
+	flag.Parse()
+	if flag.NArg() < 1 {
+		flag.Usage()
+		os.Exit(2)
+	}
+
+	if *version {
+		fmt.Printf("%s %s\n", projectName, projectVersion)
+		return
+	}
+
+	text, err := io.ReadAll(os.Stdin)
+	if err != nil {
+		log.Fatalln(err)
+	}
+
+	status := 0
+	for _, rawURL := range flag.Args() {
+		if err := notifyByURL(rawURL, text); err != nil {
+			status = 1
+
+			var ue *url.Error
+			if errors.As(err, &ue) {
+				log.Println(err)
+			} else {
+				log.Printf("notify %q: %s\n", rawURL, err)
+			}
+		}
+	}
+	os.Exit(status)
+}

xN/xN_test.go

@@ -0,0 +1,98 @@
+//
+// Copyright (c) 2024, Přemysl Eric Janouch <p@janouch.name>
+//
+// Permission to use, copy, modify, and/or distribute this software for any
+// purpose with or without fee is hereby granted.
+//
+// THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+// WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
+// MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY
+// SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+// WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION
+// OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN
+// CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+//
+
+package main
+
+import "testing"
+
+func TestParseURL(t *testing.T) {
+	for _, rawURL := range []string{
+		`irc:server/channel`,
+		`irc://server/channel,isnetwork`,
+		`ircs://ssl.ircnet.io`,
+		`ircs://ssl.ircnet.io/`,
+		`http://server/path`,
+	} {
+		if _, _, err := parse(rawURL, nil); err == nil {
+			t.Errorf("%q should not parse\n", rawURL)
+		}
+	}
+
+	for _, test := range []struct {
+		rawURL string
+		p      parameters
+	}{
+		{
+			rawURL: `irc://uptime@localhost/%23watch?skipjoin&usenotice`,
+			p: parameters{
+				username:  "uptime",
+				target:    "#watch",
+				skipjoin:  true,
+				usenotice: true,
+			},
+		},
+		{
+			rawURL: `ircs://ohayou@irc.libera.chat/john,isuser,isserver`,
+			p: parameters{
+				username: "ohayou",
+				target:   "john",
+				isuser:   true,
+			},
+		},
+		{
+			rawURL: `ircs://agent:Password123@irc.cia.gov:1337/#hq?key=123456`,
+			p: parameters{
+				username: "agent",
+				password: "Password123",
+				target:   "#hq",
+				chankey:  "123456",
+			},
+		},
+	} {
+		p, _, err := parse(test.rawURL, nil)
+		if err != nil {
+			t.Errorf("%q should parse, got: %s\n", test.rawURL, err)
+			continue
+		}
+		if p.username != test.p.username {
+			t.Errorf("%q: username: %v ≠ %v\n",
+				test.rawURL, p.username, test.p.username)
+		}
+		if p.password != test.p.password {
+			t.Errorf("%q: password: %v ≠ %v\n",
+				test.rawURL, p.password, test.p.password)
+		}
+		if p.target != test.p.target {
+			t.Errorf("%q: target: %v ≠ %v\n",
+				test.rawURL, p.target, test.p.target)
+		}
+		if p.isuser != test.p.isuser {
+			t.Errorf("%q: isuser: %v ≠ %v\n",
+				test.rawURL, p.isuser, test.p.isuser)
+		}
+		if p.chankey != test.p.chankey {
+			t.Errorf("%q: chankey: %v ≠ %v\n",
+				test.rawURL, p.chankey, test.p.chankey)
+		}
+		if p.skipjoin != test.p.skipjoin {
+			t.Errorf("%q: skipjoin: %v ≠ %v\n",
+				test.rawURL, p.skipjoin, test.p.skipjoin)
+		}
+		if p.usenotice != test.p.usenotice {
+			t.Errorf("%q: usenotice: %v ≠ %v\n",
+				test.rawURL, p.usenotice, test.p.usenotice)
+		}
+	}
+}

xP/public/xP.js

@@ -197,6 +197,14 @@ function bufferResetStats(b) {
 	b.highlighted = false
 }
 
+function bufferPopExcessLines(b) {
+	// Let "new" messages be, if only because pulling the log file
+	// is much more problematic in the web browser than in xC.
+	// TODO: Make the limit configurable, or extract general.backlog_limit.
+	const old = b.lines.length - b.newMessages - b.newUnimportantMessages
+	b.lines.splice(0, old - 1000)
+}
+
 function bufferActivate(name) {
 	rpc.send({command: 'BufferActivate', bufferName: name})
 }
@@ -294,6 +302,13 @@ rpcEventHandlers.set(Relay.Event.BufferLine, e => {
 			b.newMessages++
 	}
 
+	// XXX: In its unkeyed diff algorithm, Mithril.js can only efficiently
+	// deal with common prefixes, i.e., indefinitely growing buffers.
+	// But we don't want to key all children of Buffer,
+	// so only trim buffers while they are, or once they become invisible.
+	if (e.bufferName != bufferCurrent)
+		bufferPopExcessLines(b)
+
 	if (e.leakToActive) {
 		let bc = buffers.get(bufferCurrent)
 		bc.lines.push({...line, leaked: true})
@@ -336,7 +351,7 @@ rpcEventHandlers.set(Relay.Event.BufferStats, e => {
 	if (b === undefined)
 		return
 
-	b.newMessages = e.newMessages,
+	b.newMessages = e.newMessages
 	b.newUnimportantMessages = e.newUnimportantMessages
 	b.highlighted = e.highlighted
 })
@@ -344,6 +359,11 @@ rpcEventHandlers.set(Relay.Event.BufferStats, e => {
 rpcEventHandlers.set(Relay.Event.BufferRename, e => {
 	buffers.set(e.new, buffers.get(e.bufferName))
 	buffers.delete(e.bufferName)
+
+	if (e.bufferName === bufferCurrent)
+		bufferCurrent = e.new
+	if (e.bufferName === bufferLast)
+		bufferLast = e.new
 })
 
 rpcEventHandlers.set(Relay.Event.BufferRemove, e => {
@@ -354,8 +374,16 @@ rpcEventHandlers.set(Relay.Event.BufferRemove, e => {
 
 rpcEventHandlers.set(Relay.Event.BufferActivate, e => {
 	let old = buffers.get(bufferCurrent)
-	if (old !== undefined)
+	if (old !== undefined) {
 		bufferResetStats(old)
+		bufferPopExcessLines(old)
+	}
+
+	// Initial sync: trim all buffers to our limit, just for consistency.
+	if (bufferCurrent === undefined) {
+		for (let b of buffers.values())
+			bufferPopExcessLines(b)
+	}
 
 	bufferLast = bufferCurrent
 	let b = buffers.get(e.bufferName)
@@ -501,7 +529,8 @@ let Content = {
 		while ((match = re.exec(text)) !== null) {
 			if (end < match.index)
 				a.push(m('span', attrs, text.substring(end, match.index)))
-			a.push(m('a[target=_blank]', {href: match[0], ...attrs}, match[0]))
+			a.push(m('a[target=_blank][rel=noreferrer]',
+				{href: match[0], ...attrs}, match[0]))
 			end = re.lastIndex
 		}
 		if (end < text.length)
@@ -664,6 +693,12 @@ let Buffer = {
 			const dom = event.target
 			bufferAutoscroll =
 				dom.scrollTop + dom.clientHeight + 1 >= dom.scrollHeight
+
+			let b = buffers.get(bufferCurrent)
+			if (b !== undefined && b.highlighted && !bufferAutoscroll) {
+				b.highlighted = false
+				m.redraw()
+			}
 		}}, lines)
 	},
 }
@@ -679,7 +714,8 @@ let Log = {
 		while ((match = re.exec(text)) !== null) {
 			if (end < match.index)
 				a.push(text.substring(end, match.index))
-			a.push(m('a[target=_blank]', {href: match[0]}, match[0]))
+			a.push(m('a[target=_blank][rel=noreferrer]',
+				{href: match[0]}, match[0]))
 			end = re.lastIndex
 		}
 		if (end < text.length)
@@ -967,7 +1003,7 @@ let Input = {
 		rpc.send({command: 'Active'})
 
 		let b = buffers.get(bufferCurrent)
-		if (b === undefined)
+		if (b === undefined || event.isComposing)
 			return
 
 		let textarea = event.currentTarget

xS/Makefile

@@ -12,5 +12,7 @@ xS-replies.go: xS-gen-replies.awk xS-replies
 xS.1: ../xK-version ../liberty/tools/asciiman.awk xS.adoc
 	env "asciidoc-release-version=$$(cat ../xK-version)" \
 		$(AWK) -f ../liberty/tools/asciiman.awk xS.adoc > $@
+test: all
+	go test
 clean:
 	rm -f $(outputs)

xS/irc.go

@@ -0,0 +1,132 @@
+package main
+
+import (
+	"path/filepath"
+	"regexp"
+	"strings"
+)
+
+func ircToLower(c byte) byte {
+	switch c {
+	case '[':
+		return '{'
+	case ']':
+		return '}'
+	case '\\':
+		return '|'
+	case '~':
+		return '^'
+	}
+	if c >= 'A' && c <= 'Z' {
+		return c + ('a' - 'A')
+	}
+	return c
+}
+
+func ircToUpper(c byte) byte {
+	switch c {
+	case '{':
+		return '['
+	case '}':
+		return ']'
+	case '|':
+		return '\\'
+	case '^':
+		return '~'
+	}
+	if c >= 'a' && c <= 'z' {
+		return c - ('a' - 'A')
+	}
+	return c
+}
+
+// Convert identifier to a canonical form for case-insensitive comparisons.
+// ircToUpper is used so that statically initialized maps can be in uppercase.
+func ircToCanon(ident string) string {
+	var canon []byte
+	for _, c := range []byte(ident) {
+		canon = append(canon, ircToUpper(c))
+	}
+	return string(canon)
+}
+
+func ircEqual(s1, s2 string) bool {
+	return ircToCanon(s1) == ircToCanon(s2)
+}
+
+func ircFnmatch(pattern string, s string) bool {
+	pattern, s = ircToCanon(pattern), ircToCanon(s)
+	// FIXME: This should not support [] ranges and handle '/' specially.
+	// We could translate the pattern to a regular expression.
+	matched, _ := filepath.Match(pattern, s)
+	return matched
+}
+
+var reMsg = regexp.MustCompile(
+	`^(?:@([^ ]*) +)?(?::([^! ]*)(?:!([^@]*)@([^ ]*))? +)?([^ ]+)(.*)?$`)
+var reArgs = regexp.MustCompile(`:.*| [^: ][^ ]*`)
+
+type message struct {
+	tags    map[string]string // IRC 3.2 message tags
+	nick    string            // optional nickname
+	user    string            // optional username
+	host    string            // optional hostname or IP address
+	command string            // command name
+	params  []string          // arguments
+}
+
+func ircUnescapeMessageTag(value string) string {
+	var buf []byte
+	escape := false
+	for i := 0; i < len(value); i++ {
+		if escape {
+			switch value[i] {
+			case ':':
+				buf = append(buf, ';')
+			case 's':
+				buf = append(buf, ' ')
+			case 'r':
+				buf = append(buf, '\r')
+			case 'n':
+				buf = append(buf, '\n')
+			default:
+				buf = append(buf, value[i])
+			}
+			escape = false
+		} else if value[i] == '\\' {
+			escape = true
+		} else {
+			buf = append(buf, value[i])
+		}
+	}
+	return string(buf)
+}
+
+func ircParseMessageTags(tags string, out map[string]string) {
+	for _, tag := range strings.Split(tags, ";") {
+		if tag == "" {
+			// Ignore empty.
+		} else if equal := strings.IndexByte(tag, '='); equal < 0 {
+			out[tag] = ""
+		} else {
+			out[tag[:equal]] = ircUnescapeMessageTag(tag[equal+1:])
+		}
+	}
+}
+
+func ircParseMessage(line string) *message {
+	m := reMsg.FindStringSubmatch(line)
+	if m == nil {
+		return nil
+	}
+
+	msg := message{nil, m[2], m[3], m[4], m[5], nil}
+	if m[1] != "" {
+		msg.tags = make(map[string]string)
+		ircParseMessageTags(m[1], msg.tags)
+	}
+	for _, x := range reArgs.FindAllString(m[6], -1) {
+		msg.params = append(msg.params, x[1:])
+	}
+	return &msg
+}

xS/xS.go

@@ -456,132 +456,6 @@ func (fd *floodDetector) check() bool {
 	return count <= fd.limit
 }
 
-// --- IRC protocol ------------------------------------------------------------
-
-func ircToLower(c byte) byte {
-	switch c {
-	case '[':
-		return '{'
-	case ']':
-		return '}'
-	case '\\':
-		return '|'
-	case '~':
-		return '^'
-	}
-	if c >= 'A' && c <= 'Z' {
-		return c + ('a' - 'A')
-	}
-	return c
-}
-
-func ircToUpper(c byte) byte {
-	switch c {
-	case '{':
-		return '['
-	case '}':
-		return ']'
-	case '|':
-		return '\\'
-	case '^':
-		return '~'
-	}
-	if c >= 'a' && c <= 'z' {
-		return c - ('a' - 'A')
-	}
-	return c
-}
-
-// Convert identifier to a canonical form for case-insensitive comparisons.
-// ircToUpper is used so that statically initialized maps can be in uppercase.
-func ircToCanon(ident string) string {
-	var canon []byte
-	for _, c := range []byte(ident) {
-		canon = append(canon, ircToUpper(c))
-	}
-	return string(canon)
-}
-
-func ircEqual(s1, s2 string) bool {
-	return ircToCanon(s1) == ircToCanon(s2)
-}
-
-func ircFnmatch(pattern string, s string) bool {
-	pattern, s = ircToCanon(pattern), ircToCanon(s)
-	// FIXME: This should not support [] ranges and handle '/' specially.
-	// We could translate the pattern to a regular expression.
-	matched, _ := filepath.Match(pattern, s)
-	return matched
-}
-
-var reMsg = regexp.MustCompile(
-	`^(?:@([^ ]*) +)?(?::([^! ]*)(?:!([^@]*)@([^ ]*))? +)?([^ ]+)(.*)?$`)
-var reArgs = regexp.MustCompile(`:.*| [^: ][^ ]*`)
-
-type message struct {
-	tags    map[string]string // IRC 3.2 message tags
-	nick    string            // optional nickname
-	user    string            // optional username
-	host    string            // optional hostname or IP address
-	command string            // command name
-	params  []string          // arguments
-}
-
-func ircUnescapeMessageTag(value string) string {
-	var buf []byte
-	escape := false
-	for i := 0; i < len(value); i++ {
-		if escape {
-			switch value[i] {
-			case ':':
-				buf = append(buf, ';')
-			case 's':
-				buf = append(buf, ' ')
-			case 'r':
-				buf = append(buf, '\r')
-			case 'n':
-				buf = append(buf, '\n')
-			default:
-				buf = append(buf, value[i])
-			}
-			escape = false
-		} else if value[i] == '\\' {
-			escape = true
-		} else {
-			buf = append(buf, value[i])
-		}
-	}
-	return string(buf)
-}
-
-func ircParseMessageTags(tags string, out map[string]string) {
-	for _, tag := range splitString(tags, ";", true /* ignoreEmpty */) {
-		if equal := strings.IndexByte(tag, '='); equal < 0 {
-			out[tag] = ""
-		} else {
-			out[tag[:equal]] = ircUnescapeMessageTag(tag[equal+1:])
-		}
-	}
-}
-
-func ircParseMessage(line string) *message {
-	m := reMsg.FindStringSubmatch(line)
-	if m == nil {
-		return nil
-	}
-
-	msg := message{nil, m[2], m[3], m[4], m[5], nil}
-	if m[1] != "" {
-		msg.tags = make(map[string]string)
-		ircParseMessageTags(m[1], msg.tags)
-	}
-	for _, x := range reArgs.FindAllString(m[6], -1) {
-		msg.params = append(msg.params, x[1:])
-	}
-	return &msg
-
-}
-
 // --- IRC token validation ----------------------------------------------------
 
 // Everything as per RFC 2812

xW/CMakeLists.txt

@@ -24,42 +24,22 @@ set (project_config ${PROJECT_BINARY_DIR}/config.h)
 configure_file (${PROJECT_SOURCE_DIR}/config.h.in ${project_config})
 include_directories (${PROJECT_SOURCE_DIR} ${PROJECT_BINARY_DIR})
 
-# Icon generation utilities
+# Produce a beep sample
-# TODO: Shove this into liberty as a CMake module, similar to AddThreads,
-# and remove the copies in the parent CMakeLists.txt as well as in tdv.
 if (NOT ${CMAKE_VERSION} VERSION_LESS 3.18.0)
 	set (find_program_REQUIRE REQUIRED)
 endif ()
 
-function (icon_to_png name svg size output_dir output)
+find_program (sox_EXECUTABLE sox ${find_program_REQUIRE})
-	set (_dimensions ${size}x${size})
+add_custom_command (OUTPUT beep.wav
-	set (_png_path ${output_dir}/hicolor/${_dimensions}/apps)
+	COMMAND ${sox_EXECUTABLE} -b 16 -Dr 44100 -n beep.wav
-	set (_png ${_png_path}/${name}.png)
+		synth 0.1 0 25 triangle 800 vol 0.5 fade t 0 -0 0.005 pad 0 0.05
-	set (${output} ${_png} PARENT_SCOPE)
+	COMMENT "Generating a beep sample" VERBATIM)
-
-	find_program (rsvg_convert_EXECUTABLE rsvg-convert ${find_program_REQUIRE})
-	add_custom_command (OUTPUT ${_png}
-		COMMAND ${CMAKE_COMMAND} -E make_directory ${_png_path}
-		COMMAND ${rsvg_convert_EXECUTABLE} --output=${_png}
-			--width=${size} --height=${size} ${svg}
-		DEPENDS ${svg}
-		COMMENT "Generating ${name} ${_dimensions} application icon" VERBATIM)
-endfunction ()
-
-function (icon_for_win32 ico pngs pngs_raw)
-	set (_raws)
-	foreach (png ${pngs_raw})
-		list (APPEND _raws "--raw=${png}")
-	endforeach ()
-
-	find_program (icotool_EXECUTABLE icotool ${find_program_REQUIRE})
-	add_custom_command (OUTPUT ${ico}
-		COMMAND ${icotool_EXECUTABLE} -c -o ${ico} ${_raws} -- ${pngs}
-		DEPENDS ${pngs} ${pngs_raw}
-		COMMENT "Generating Windows program icon" VERBATIM)
-endfunction ()
 
 # Rasterize SVG icons
+set (root "${PROJECT_SOURCE_DIR}/..")
+set (CMAKE_MODULE_PATH ${root}/liberty/cmake)
+include (IconUtils)
+
 set (icon_ico_list)
 foreach (icon xW xW-highlighted)
 	set (icon_png_list)
@@ -76,11 +56,10 @@ foreach (icon xW xW-highlighted)
 	list (APPEND icon_ico_list ${icon_ico})
 endforeach ()
 
-set_property (SOURCE xW.rc APPEND PROPERTY OBJECT_DEPENDS ${icon_ico_list})
+set_property (SOURCE xW.rc
+	APPEND PROPERTY OBJECT_DEPENDS ${icon_ico_list} beep.wav)
 
 # Build the main executable and link it
-set (root "${PROJECT_SOURCE_DIR}/..")
-
 find_program (awk_EXECUTABLE awk ${find_program_REQUIRE})
 add_custom_command (OUTPUT xC-proto.cpp
 	COMMAND ${CMAKE_COMMAND} -E env LC_ALL=C ${awk_EXECUTABLE}
@@ -97,7 +76,7 @@ add_custom_target (xC-proto DEPENDS ${PROJECT_BINARY_DIR}/xC-proto.cpp)
 
 add_executable (xW WIN32 xW.cpp xW.rc xW.manifest ${project_config}
 	${root}/liberty/tools/lxdrgen-cpp-win32.cpp)
-target_link_libraries (xW comctl32 ws2_32)
+target_link_libraries (xW comctl32 ws2_32 winmm)
 add_dependencies (xW xC-proto)
 
 # At least with MinGW, this is a fully independent portable executable

xW/xW-resources.h

@@ -1,5 +1,6 @@
 #define IDI_ICON                1
 #define IDI_HIGHLIGHTED         2
+#define IDR_BEEP                3
 #define IDA_ACCELERATORS       10
 
 // Named after input_add_functions() in xC.
@@ -10,3 +11,8 @@
 #define ID_GOTO_ACTIVITY       15
 #define ID_TOGGLE_UNIMPORTANT  16
 #define ID_DISPLAY_FULL_LOG    17
+
+#define IDD_CONNECT            20
+#define IDC_STATIC             21
+#define IDC_HOST               22
+#define IDC_PORT               23

xW/xW.cpp

@@ -113,10 +113,14 @@ struct {
 
 	// Networking:
 
+	std::wstring host;                  ///< Host as given by user
+	std::wstring port;                  ///< Port/service as given by user
+
 	addrinfoW *addresses;               ///< GetAddrInfo() result
 	addrinfoW *addresses_iterator;      ///< Currently processed address
 	SOCKET socket;                      ///< Relay socket
-	WSAEVENT event;                     ///< Relay socket event
+	WSAEVENT socket_event;              ///< Relay socket event
+	HANDLE flush_event;                 ///< Write buffer has new data
 	std::vector<uint8_t> write_buffer;  ///< Write buffer
 	std::vector<uint8_t> read_buffer;   ///< Read buffer
 
@@ -153,6 +157,23 @@ format_error_message(int err)
 	return copy;
 }
 
+static std::wstring
+window_get_text(HWND hWnd)
+{
+	int length = GetWindowTextLength(hWnd);
+	std::wstring buffer(length, {});
+	GetWindowText(hWnd, buffer.data(), length + 1);
+	return buffer;
+}
+
+static void
+beep()
+{
+	if (!PlaySound(MAKEINTRESOURCE(IDR_BEEP),
+			GetModuleHandle(NULL), SND_ASYNC | SND_RESOURCE))
+		Beep(800, 100);
+}
+
 // --- Networking --------------------------------------------------------------
 
 static bool
@@ -181,6 +202,8 @@ relay_try_read(std::wstring &error)
 static bool
 relay_try_write(std::wstring &error)
 {
+	ResetEvent(g.flush_event);
+
 	auto &w = g.write_buffer;
 	int err = {};
 	while (!w.empty()) {
@@ -215,18 +238,10 @@ relay_send(Relay::CommandData *data, Callback callback = {})
 	g.write_buffer.insert(g.write_buffer.end(), prefix, prefix + sizeof len);
 	g.write_buffer.insert(g.write_buffer.end(), w.data.begin(), w.data.end());
 
-	// Call relay_try_write() separately.
+	// There doesn't seem to be a way to cause FD_WRITE without first
-}
+	// unsuccessfully trying to send some data, but we don't want to
-
+	// handle any errors at this level.
-static void
+	SetEvent(g.flush_event);
-relay_send_now(Relay::CommandData *data, Callback callback = {})
-{
-	relay_send(data, callback);
-
-	// TODO(p): Either tear down here, or run relay_try_write() from a timer.
-	std::wstring error;
-	if (!relay_try_write(error))
-		show_error_message(error.c_str());
 }
 
 // --- Buffers -----------------------------------------------------------------
@@ -245,7 +260,7 @@ buffer_activate(const std::wstring &name)
 {
 	auto activate = new Relay::CommandData_BufferActivate();
 	activate->buffer_name = name;
-	relay_send_now(activate);
+	relay_send(activate);
 }
 
 static void
@@ -253,7 +268,7 @@ buffer_toggle_unimportant(const std::wstring &name)
 {
 	auto toggle = new Relay::CommandData_BufferToggleUnimportant();
 	toggle->buffer_name = name;
-	relay_send_now(toggle);
+	relay_send(toggle);
 }
 
 // --- Current buffer ----------------------------------------------------------
@@ -299,7 +314,7 @@ buffer_toggle_log()
 
 	auto log = new Relay::CommandData_BufferLog();
 	log->buffer_name = g.buffer_current;
-	relay_send_now(log, [name = g.buffer_current](auto error, auto response) {
+	relay_send(log, [name = g.buffer_current](auto error, auto response) {
 		if (g.buffer_current != name)
 			return;
 		buffer_toggle_log(error,
@@ -411,10 +426,7 @@ refresh_status()
 	}
 
 	// Buffer scrolling would cause a ton of flickering redraws.
-	int length = GetWindowTextLength(g.hwndStatus);
+	if (window_get_text(g.hwndStatus) != status)
-	std::wstring buffer(length, {});
-	GetWindowText(g.hwndStatus, buffer.data(), length + 1);
-	if (buffer != status)
 		SetWindowText(g.hwndStatus, status.c_str());
 }
 
@@ -499,7 +511,7 @@ convert_item_formatting(Relay::ItemData *item, CHARFORMAT2 &cf, bool &inverse)
 }
 
 static std::vector<BufferLineItem>
-convert_items(std::vector<std::unique_ptr<Relay::ItemData>> &items)
+convert_items(const std::vector<std::unique_ptr<Relay::ItemData>> &items)
 {
 	CHARFORMAT2 cf = default_charformat();
 	std::vector<BufferLineItem> result;
@@ -666,14 +678,12 @@ buffer_print_line(std::vector<BufferLine>::const_iterator begin,
 		if (!prefix.empty())
 			richedit_replacesel(g.hwndBuffer, &pcf, prefix.c_str());
 
-		std::wstring text;
+		for (auto it : line->items) {
-		for (const auto &it : line->items)
+			it.format.dwEffects &= ~CFE_AUTOCOLOR;
-			text += it.text;
+			it.format.crTextColor = GetSysColor(COLOR_GRAYTEXT);
-
+			it.format.dwEffects |= CFE_AUTOBACKCOLOR;
-		CHARFORMAT2 format = default_charformat();
+			richedit_replacesel(g.hwndBuffer, &it.format, it.text.c_str());
-		format.dwEffects &= ~CFE_AUTOCOLOR;
+		}
-		format.crTextColor = GetSysColor(COLOR_GRAYTEXT);
-		richedit_replacesel(g.hwndBuffer, &format, text.c_str());
 	} else {
 		if (!prefix.empty())
 			richedit_replacesel(g.hwndBuffer, &pcf, prefix.c_str());
@@ -685,10 +695,12 @@ buffer_print_line(std::vector<BufferLine>::const_iterator begin,
 static void
 buffer_print_separator()
 {
+	bool sameline = !GetWindowTextLength(g.hwndBuffer);
+
 	CHARFORMAT2 format = default_charformat();
 	format.dwEffects &= ~CFE_AUTOCOLOR;
 	format.crTextColor = RGB(0xff, 0x5f, 0x00);
-	richedit_replacesel(g.hwndBuffer, &format, L"\n---");
+	richedit_replacesel(g.hwndBuffer, &format, &L"\n---"[sameline]);
 }
 
 static void
@@ -774,8 +786,7 @@ relay_process_buffer_line(Buffer &b, Relay::EventData_BufferLine &m)
 
 	if (line->is_highlight || (!visible && !line->is_unimportant &&
 		b.kind == Relay::BufferKind::PRIVATE_MESSAGE)) {
-		// TODO(p): Avoid the PC speaker, which is also unreliable.
+		beep();
-		Beep(800, 100);
 
 		if (!visible) {
 			b.highlighted = true;
@@ -809,8 +820,6 @@ relay_process_callbacks(uint32_t command_seq,
 	}
 }
 
-static std::wstring input_get_contents();
-
 static void
 relay_process_message(const Relay::EventMessage &m)
 {
@@ -903,11 +912,15 @@ relay_process_message(const Relay::EventMessage &m)
 		if (!b)
 			break;
 
-		b->buffer_name = data.buffer_name;
+		b->buffer_name = data.new_;
 
 		refresh_buffer_list();
-		if (b->buffer_name == g.buffer_current)
+		if (data.buffer_name == g.buffer_current) {
+			g.buffer_current = data.new_;
 			refresh_status();
+		}
+		if (data.buffer_name == g.buffer_last)
+			g.buffer_last = data.new_;
 		break;
 	}
 	case Relay::Event::BUFFER_REMOVE:
@@ -939,7 +952,7 @@ relay_process_message(const Relay::EventMessage &m)
 			old->new_unimportant_messages = 0;
 			old->highlighted = false;
 
-			old->input = input_get_contents();
+			old->input = window_get_text(g.hwndInput);
 			SendMessage(g.hwndInput, EM_GETSEL,
 				(WPARAM) &old->input_start, (LPARAM) &old->input_end);
 
@@ -954,6 +967,7 @@ relay_process_message(const Relay::EventMessage &m)
 			b->highlighted = false;
 		SendMessage(g.hwndBufferList, LB_SETCURSEL, b - g.buffers.data(), 0);
 
+		refresh_icon();
 		refresh_topic(b->topic);
 		refresh_buffer(*b);
 		refresh_prompt();
@@ -1067,8 +1081,8 @@ relay_destroy_socket()
 {
 	closesocket(g.socket);
 	g.socket = INVALID_SOCKET;
-	WSACloseEvent(g.event);
+	WSACloseEvent(g.socket_event);
-	g.event = NULL;
+	g.socket_event = NULL;
 
 	g.read_buffer.clear();
 	g.write_buffer.clear();
@@ -1089,8 +1103,8 @@ relay_connect_step(std::wstring& error)
 		return false;
 	}
 
-	g.event = WSACreateEvent();
+	g.socket_event = WSACreateEvent();
-	if (WSAEventSelect(g.socket, g.event,
+	if (WSAEventSelect(g.socket, g.socket_event,
 			FD_CONNECT | FD_READ | FD_WRITE | FD_CLOSE))
 		error = format_error_message(WSAGetLastError());
 	else if (!connect(g.socket, p->ai_addr, (int) p->ai_addrlen))
@@ -1160,7 +1174,7 @@ static bool
 relay_process_socket_events(std::wstring &error)
 {
 	WSANETWORKEVENTS wne = {};
-	if (WSAEnumNetworkEvents(g.socket, g.event, &wne)) {
+	if (WSAEnumNetworkEvents(g.socket, g.socket_event, &wne)) {
 		error = format_error_message(WSAGetLastError());
 		return false;
 	}
@@ -1180,15 +1194,6 @@ relay_process_socket_events(std::wstring &error)
 
 // --- Input line --------------------------------------------------------------
 
-static std::wstring
-input_get_contents()
-{
-	int length = GetWindowTextLength(g.hwndInput);
-	std::wstring buffer(length, {});
-	GetWindowText(g.hwndInput, buffer.data(), length + 1);
-	return buffer;
-}
-
 static void
 input_set_contents(const std::wstring &input)
 {
@@ -1206,7 +1211,7 @@ input_submit()
 
 	auto input = new Relay::CommandData_BufferInput();
 	input->buffer_name = b->buffer_name;
-	input->text = input_get_contents();
+	input->text = window_get_text(g.hwndInput);
 
 	// Buffer::history[Buffer::history.size()] is virtual,
 	// and is represented either by edit contents when it's currently
@@ -1215,7 +1220,7 @@ input_submit()
 	b->history_at = b->history.size();
 	input_set_contents({});
 
-	relay_send_now(input);
+	relay_send(input);
 	return true;
 }
 
@@ -1230,7 +1235,7 @@ input_stamp()
 {
 	DWORD start = {}, end = {};
 	SendMessage(g.hwndInput, EM_GETSEL, (WPARAM) &start, (LPARAM) &end);
-	return {start, end, input_get_contents()};
+	return {start, end, window_get_text(g.hwndInput)};
 }
 
 static void
@@ -1260,9 +1265,8 @@ input_complete(const InputStamp &state, const std::wstring &error,
 		SendMessage(g.hwndInput, EM_REPLACESEL, TRUE, (LPARAM) insert.c_str());
 	}
 
-	// TODO(p): Avoid the PC speaker, which is also unreliable.
 	if (response->completions.size() != 1)
-		Beep(800, 100);
+		beep();
 
 	// TODO(p): Show all completion options.
 }
@@ -1283,7 +1287,7 @@ input_complete()
 	complete->buffer_name = g.buffer_current;
 	complete->text = state.input;
 	complete->position = utf8.length();
-	relay_send_now(complete, [state](auto error, auto response) {
+	relay_send(complete, [state](auto error, auto response) {
 		auto stamp = input_stamp();
 		if (std::make_tuple(stamp.start, stamp.end, stamp.input) !=
 			std::make_tuple(state.start, state.end, state.input))
@@ -1294,6 +1298,32 @@ input_complete()
 	return true;
 }
 
+static bool
+input_up()
+{
+	auto b = buffer_by_name(g.buffer_current);
+	if (!b || b->history_at < 1)
+		return false;
+
+	if (b->history_at == b->history.size())
+		b->input = window_get_text(g.hwndInput);
+	input_set_contents(b->history.at(--b->history_at));
+	return true;
+}
+
+static bool
+input_down()
+{
+	auto b = buffer_by_name(g.buffer_current);
+	if (!b || b->history_at >= b->history.size())
+		return false;
+
+	input_set_contents(++b->history_at == b->history.size()
+		? b->input
+		: b->history.at(b->history_at));
+	return true;
+}
+
 static boolean
 input_wants(const MSG *message)
 {
@@ -1325,34 +1355,18 @@ input_proc(HWND hWnd, UINT uMsg, WPARAM wParam, LPARAM lParam,
 		return lResult;
 	}
 	case WM_SYSCHAR:
-	{
-		auto b = buffer_by_name(g.buffer_current);
-		if (!b)
-			break;
-
 		// TODO(p): Emacs-style cursor movement shortcuts.
 		switch (wParam) {
 		case 'p':
-		{
+			if (input_up())
-			if (b->history_at < 1)
+				return 0;
-				break;
+			break;
-			if (b->history_at == b->history.size())
-				b->input = input_get_contents();
-			input_set_contents(b->history.at(--b->history_at));
-			return 0;
-		}
 		case 'n':
-		{
+			if (input_down())
-			if (b->history_at >= b->history.size())
+				return 0;
-				break;
+			break;
-			input_set_contents(++b->history_at == b->history.size()
-				? b->input
-				: b->history.at(b->history_at));
-			return 0;
-		}
 		}
 		break;
-	}
 	case WM_KEYDOWN:
 	{
 		HWND scrollable = IsWindowVisible(g.hwndBufferLog)
@@ -1360,6 +1374,14 @@ input_proc(HWND hWnd, UINT uMsg, WPARAM wParam, LPARAM lParam,
 			: g.hwndBuffer;
 
 		switch (wParam) {
+		case VK_UP:
+			if (input_up())
+				return 0;
+			break;
+		case VK_DOWN:
+			if (input_down())
+				return 0;
+			break;
 		case VK_PRIOR:
 			SendMessage(scrollable, EM_SCROLL, SB_PAGEUP, 0);
 			return 0;
@@ -1372,7 +1394,7 @@ input_proc(HWND hWnd, UINT uMsg, WPARAM wParam, LPARAM lParam,
 	case WM_CHAR:
 	{
 		// This could be implemented more precisely, but it will do.
-		relay_send_now(new Relay::CommandData_Active());
+		relay_send(new Relay::CommandData_Active());
 
 		switch (wParam) {
 		case VK_RETURN:
@@ -1412,7 +1434,7 @@ bufferlist_proc(HWND hWnd, UINT uMsg, WPARAM wParam, LPARAM lParam,
 		auto input = new Relay::CommandData_BufferInput();
 		input->buffer_name = g.buffer_current;
 		input->text = L"/buffer close " + g.buffers.at(index).buffer_name;
-		relay_send_now(input);
+		relay_send(input);
 		return 0;
 	}
 	case WM_NCDESTROY:
@@ -1627,6 +1649,21 @@ window_proc(HWND hWnd, UINT uMsg, WPARAM wParam, LPARAM lParam)
 		if (auto b = buffer_by_name(g.buffer_current))
 			refresh_buffer(*b);
 		return 0;
+	case WM_SYSCOLORCHANGE:
+		// The topic would flicker with WS_EX_TRANSPARENT.
+		// The buffer only changed its text colour, not background.
+		SendMessage(g.hwndTopic,
+			EM_SETBKGNDCOLOR, 0, GetSysColor(COLOR_3DFACE));
+		SendMessage(g.hwndBuffer,
+			EM_SETBKGNDCOLOR, 1, 0);
+
+		// XXX: This is incomplete, we'd have to run convert_items() again;
+		// essentially only COLOR_GRAYTEXT is reloaded in here.
+		if (auto b = buffer_by_name(g.buffer_current))
+			refresh_buffer(*b);
+
+		// Pass it to all child windows, through DefWindowProc().
+		break;
 	case WM_ACTIVATE:
 		if (LOWORD(wParam) == WA_INACTIVE)
 			g.hwndLastFocused = GetFocus();
@@ -1683,10 +1720,33 @@ window_proc(HWND hWnd, UINT uMsg, WPARAM wParam, LPARAM lParam)
 			break;
 		}
 		}
+	case DM_GETDEFID:
+	case DM_SETDEFID:
+		break;
 	}
 	return DefWindowProc(hWnd, uMsg, wParam, lParam);
 }
 
+static INT_PTR CALLBACK
+connect_proc(
+	HWND hDlg, UINT uMsg, WPARAM wParam, [[maybe_unused]] LPARAM lParam)
+{
+	switch (uMsg) {
+	case WM_INITDIALOG:
+		return TRUE;
+	case WM_COMMAND:
+		switch (LOWORD(wParam)) {
+		case IDOK:
+		case IDCANCEL:
+			g.host = window_get_text(GetDlgItem(hDlg, IDC_HOST));
+			g.port = window_get_text(GetDlgItem(hDlg, IDC_PORT));
+			EndDialog(hDlg, LOWORD(wParam));
+			return TRUE;
+		}
+	}
+	return FALSE;
+}
+
 static void
 get_font()
 {
@@ -1865,11 +1925,14 @@ wWinMain(HINSTANCE hInstance, [[maybe_unused]] HINSTANCE hPrevInstance,
 
 	int argc = 0;
 	LPWSTR *argv = CommandLineToArgvW(pCmdLine, &argc);
-	if (argc < 2) {
+	if (argc >= 2) {
-		show_error_message(
+		g.host = argv[0];
-			L"You must pass the relay address and port on the command line.");
+		g.port = argv[1];
-		return 1;
+	} else if (DialogBox(hInstance, MAKEINTRESOURCE(IDD_CONNECT),
+			g.hwndMain, connect_proc) != IDOK) {
+		return 0;
 	}
+	LocalFree(argv);
 
 	// We have a few suboptimal asynchronous options:
 	// a) WSAAsyncGetHostByName() requires us to distinguish hostnames
@@ -1880,8 +1943,7 @@ wWinMain(HINSTANCE hInstance, [[maybe_unused]] HINSTANCE hPrevInstance,
 	hints.ai_family = AF_UNSPEC;
 	hints.ai_socktype = SOCK_STREAM;
 	hints.ai_protocol = IPPROTO_TCP;
-	err = GetAddrInfo(argv[0], argv[1], &hints, &g.addresses);
+	err = GetAddrInfo(g.host.c_str(), g.port.c_str(), &hints, &g.addresses);
-	LocalFree(argv);
 	if (err) {
 		show_error_message(format_error_message(err).c_str());
 		return 1;
@@ -1894,15 +1956,15 @@ wWinMain(HINSTANCE hInstance, [[maybe_unused]] HINSTANCE hPrevInstance,
 		return 1;
 	}
 
-	g.date_change_timer = CreateWaitableTimer(NULL, FALSE, NULL);
+	if (!(g.date_change_timer = CreateWaitableTimer(NULL, FALSE, NULL)) ||
-	if (!g.date_change_timer) {
+			!(g.flush_event = CreateEvent(NULL, FALSE, FALSE, NULL))) {
 		show_error_message(format_error_message(GetLastError()).c_str());
 		return 1;
 	}
 
 	while (process_messages(accelerators)) {
-		HANDLE handles[] = {g.date_change_timer, g.event};
+		HANDLE handles[] = {g.date_change_timer, g.flush_event, g.socket_event};
-		DWORD count = 2 - !handles[1];
+		DWORD count = 3 - !handles[2];
 		DWORD result = MsgWaitForMultipleObjects(
 			count, handles, FALSE, INFINITE, QS_ALLINPUT);
 		if (result == WAIT_FAILED) {
@@ -1919,7 +1981,11 @@ wWinMain(HINSTANCE hInstance, [[maybe_unused]] HINSTANCE hPrevInstance,
 			if (to_bottom)
 				buffer_scroll_to_bottom();
 		}
-		if (signalled == g.event && !relay_process_socket_events(error)) {
+		if (signalled == g.flush_event && !relay_try_write(error)) {
+			show_error_message(error.c_str());
+			return 1;
+		}
+		if (signalled == g.socket_event && !relay_process_socket_events(error)) {
 			show_error_message(error.c_str());
 			return 1;
 		}
@@ -1927,5 +1993,6 @@ wWinMain(HINSTANCE hInstance, [[maybe_unused]] HINSTANCE hPrevInstance,
 	FreeAddrInfo(g.addresses);
 	WSACleanup();
 	CloseHandle(g.date_change_timer);
+	CloseHandle(g.flush_event);
 	return 0;
 }

xW/xW.manifest

@@ -8,4 +8,18 @@
 				publicKeyToken="6595b64144ccf1df" language="*" />
 		</dependentAssembly>
 	</dependency>
+	<compatibility xmlns="urn:schemas-microsoft-com:compatibility.v1">
+		<application>
+			<!-- Windows 10 -->
+			<supportedOS Id="{8e0f7a12-bfb3-4fe8-b9a5-48fd50a15a9a}" />
+			<!-- Windows 8.1 -->
+			<supportedOS Id="{1f676c76-80e1-4239-95bb-83d0f6d0da78}" />
+			<!-- Windows 8 -->
+			<supportedOS Id="{4a2f28e3-53b9-4441-ba9c-d69d4a4a6e38}" />
+			<!-- Windows 7 -->
+			<supportedOS Id="{35138b9a-5d96-4fbd-8e2d-a2440225f93a}" />
+			<!-- Windows Vista -->
+			<supportedOS Id="{e2011457-1546-43c5-a5fe-008deee3d3f0}" />
+		</application>
+	</compatibility>
 </assembly>

xW/xW.rc

@@ -12,6 +12,7 @@ CREATEPROCESS_MANIFEST_RESOURCE_ID RT_MANIFEST "xW.manifest"
 
 IDI_ICON ICON "xW.ico"
 IDI_HIGHLIGHTED ICON "xW-highlighted.ico"
+IDR_BEEP WAVE "beep.wav"
 
 IDA_ACCELERATORS ACCELERATORS
 BEGIN
@@ -31,6 +32,27 @@ BEGIN
 #endif
 END
 
+// https://devblogs.microsoft.com/oldnewthing/20050204-00/?p=36523
+// https://devblogs.microsoft.com/oldnewthing/20050207-00/?p=36513
+//
+// Note that this is still not the right font to use in newest Windows,
+// that would be 9pt Segoe UI, as described in:
+// https://learn.microsoft.com/en-us/windows/win32/uxguide/vis-fonts
+// or even better yet, NONCLIENTMETRICS::lfMessageFont.
+IDD_CONNECT DIALOGEX 0, 0, 150, 64
+STYLE DS_SHELLFONT | DS_MODALFRAME | DS_CENTER \
+	| WS_POPUP | WS_CAPTION | WS_SYSMENU
+CAPTION "Connect to Relay"
+FONT 8, "MS Shell Dlg", 400 /*FW_NORMAL*/, 0 /*FALSE*/, 0x1 /*DEFAULT_CHARSET*/
+BEGIN
+	LTEXT         "&Host:",   IDC_STATIC, 7, 10,  18,  8
+	EDITTEXT                  IDC_HOST,  39,  7, 104, 14, ES_AUTOHSCROLL
+	LTEXT         "&Port:",   IDC_STATIC, 7, 28,  18,  8
+	EDITTEXT                  IDC_PORT,  39, 25, 104, 14, ES_AUTOHSCROLL
+	DEFPUSHBUTTON "&Connect", IDOK,      39, 43,  50, 14
+	PUSHBUTTON    "E&xit",    IDCANCEL,  93, 43,  50, 14
+END
+
 VS_VERSION_INFO VERSIONINFO
 FILEVERSION     PROJECT_MAJOR, PROJECT_MINOR, PROJECT_PATCH, PROJECT_TWEAK
 PRODUCTVERSION  PROJECT_MAJOR, PROJECT_MINOR, PROJECT_PATCH, PROJECT_TWEAK