Bump version, update NEWS

To some extent they duplicate the README but from a different angle.

CMakeLists.txt

@@ -1,5 +1,5 @@
-project (uirc3 C)
-cmake_minimum_required (VERSION 2.8.11)
+cmake_minimum_required (VERSION 3.0)
+project (uirc3 VERSION 1.0.0 LANGUAGES C)
 
 # Options
 option (WANT_READLINE "Use GNU Readline for the UI (better)" ON)
@@ -10,13 +10,15 @@ if ("${CMAKE_C_COMPILER_ID}" MATCHES "GNU" OR CMAKE_COMPILER_IS_GNUCC)
 	# -Wunused-function is pretty annoying here, as everything is static
 	set (wdisabled "-Wno-unused-function")
 	set (CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -std=c99 -Wall -Wextra ${wdisabled}")
-endif ("${CMAKE_C_COMPILER_ID}" MATCHES "GNU" OR CMAKE_COMPILER_IS_GNUCC)
+endif ()
 
 # Version
-set (project_version "0.9.7")
+set (project_version "${PROJECT_VERSION}")
 
 # Try to append commit ID if it follows a version tag.  It might be nicer if
 # we could also detect dirty worktrees but that's very hard to get right.
+# If we didn't need this for CPack, we could use add_custom_command to generate
+# a version source/include file.
 find_package (Git)
 set (git_head "${PROJECT_SOURCE_DIR}/.git/HEAD")
 if (GIT_FOUND AND EXISTS "${git_head}")
@@ -26,8 +28,8 @@ if (GIT_FOUND AND EXISTS "${git_head}")
 		set (git_ref "${PROJECT_SOURCE_DIR}/.git/${CMAKE_MATCH_1}")
 		if (EXISTS "${git_ref}")
 			configure_file ("${git_ref}" git-ref.tag COPYONLY)
-		endif (EXISTS "${git_ref}")
-	endif (git_head_content MATCHES "^ref: ([^\r\n]+)")
+		endif ()
+	endif ()
 
 	execute_process (COMMAND ${GIT_EXECUTABLE} describe --tags --match v*
 		WORKING_DIRECTORY ${PROJECT_SOURCE_DIR}
@@ -35,8 +37,8 @@ if (GIT_FOUND AND EXISTS "${git_head}")
 		OUTPUT_VARIABLE git_describe OUTPUT_STRIP_TRAILING_WHITESPACE)
 	if (NOT git_describe_result)
 		string (REGEX REPLACE "^v" "" project_version "${git_describe}")
-	endif (NOT git_describe_result)
-endif (GIT_FOUND AND EXISTS "${git_head}")
+	endif ()
+endif ()
 
 # Dashes make filenames confusing and upset packaging software
 string (REPLACE "-" "+" project_version_safe "${project_version}")
@@ -57,7 +59,7 @@ if ("${CMAKE_SYSTEM_NAME}" MATCHES "BSD")
 	# Need this for SIGWINCH in FreeBSD and OpenBSD respectively;
 	# our POSIX version macros make it undefined
 	add_definitions (-D__BSD_VISIBLE=1 -D_BSD_SOURCE=1)
-endif ("${CMAKE_SYSTEM_NAME}" MATCHES "BSD")
+endif ()
 
 # -lrt is only for glibc < 2.17
 # -liconv may or may not be a part of libc
@@ -65,8 +67,8 @@ foreach (extra iconv rt)
 	find_library (extra_lib_${extra} ${extra})
 	if (extra_lib_${extra})
 		list (APPEND project_libraries ${extra_lib_${extra}})
-	endif (extra_lib_${extra})
-endforeach (extra)
+	endif ()
+endforeach ()
 
 include (CheckCSourceRuns)
 set (CMAKE_REQUIRED_LIBRARIES ${project_libraries})
@@ -82,19 +84,19 @@ list (APPEND degesch_libraries ${libffi_LIBRARIES})
 include_directories (${libffi_INCLUDE_DIRS})
 link_directories (${libffi_LIBRARY_DIRS})
 
-# FIXME: other Lua versions may be acceptable, don't know yet
-pkg_search_module (lua lua53 lua5.3 lua-5.3 lua>=5.3)
+# XXX: other Lua versions may be acceptable, don't know yet
+pkg_search_module (lua lua53 lua5.3 lua-5.3 lua54 lua5.4 lua-5.4 lua>=5.3)
 option (WITH_LUA "Enable support for Lua plugins" ${lua_FOUND})
 
 if (WITH_LUA)
 	if (NOT lua_FOUND)
 		message (FATAL_ERROR "Lua library not found")
-	endif (NOT lua_FOUND)
+	endif ()
 
 	list (APPEND degesch_libraries ${lua_LIBRARIES})
 	include_directories (${lua_INCLUDE_DIRS})
 	link_directories (${lua_LIBRARY_DIRS})
-endif (WITH_LUA)
+endif ()
 
 find_package (Curses)
 pkg_check_modules (ncursesw ncursesw)
@@ -104,9 +106,9 @@ if (ncursesw_FOUND)
 elseif (CURSES_FOUND)
 	list (APPEND degesch_libraries ${CURSES_LIBRARY})
 	include_directories (${CURSES_INCLUDE_DIR})
-else (CURSES_FOUND)
+else ()
 	message (SEND_ERROR "Curses not found")
-endif (ncursesw_FOUND)
+endif ()
 
 if ((WANT_READLINE AND WANT_LIBEDIT) OR (NOT WANT_READLINE AND NOT WANT_LIBEDIT))
 	message (SEND_ERROR "You have to choose either GNU Readline or libedit")
@@ -115,14 +117,14 @@ elseif (WANT_READLINE)
 	if ("${CMAKE_SYSTEM_NAME}" MATCHES "OpenBSD")
 		include_directories (/usr/local/include/ereadline)
 		list (APPEND degesch_libraries ereadline)
-	else ("${CMAKE_SYSTEM_NAME}" MATCHES "OpenBSD")
+	else ()
 		list (APPEND degesch_libraries readline)
-	endif ("${CMAKE_SYSTEM_NAME}" MATCHES "OpenBSD")
+	endif ()
 elseif (WANT_LIBEDIT)
 	pkg_check_modules (libedit REQUIRED libedit)
 	list (APPEND degesch_libraries ${libedit_LIBRARIES})
 	include_directories (${libedit_INCLUDE_DIRS})
-endif ((WANT_READLINE AND WANT_LIBEDIT) OR (NOT WANT_READLINE AND NOT WANT_LIBEDIT))
+endif ()
 
 # Generate a configuration file
 set (HAVE_READLINE "${WANT_READLINE}")
@@ -130,59 +132,41 @@ set (HAVE_EDITLINE "${WANT_LIBEDIT}")
 set (HAVE_LUA      "${WITH_LUA}")
 
 include (GNUInstallDirs)
-# ZyklonB is currently an odd duck but degesch follows normal XDG rules
-set (zyklonb_plugin_dir ${CMAKE_INSTALL_LIBDIR}/zyklonb/plugins)
 configure_file (${PROJECT_SOURCE_DIR}/config.h.in ${PROJECT_BINARY_DIR}/config.h)
 include_directories (${PROJECT_SOURCE_DIR} ${PROJECT_BINARY_DIR})
 
-# Project source files
-set (common_sources)
-set (common_headers ${PROJECT_BINARY_DIR}/config.h)
-
+# Generate IRC replies--we need a custom target because of the multiple outputs
 add_custom_command (OUTPUT kike-replies.c kike.msg
 	COMMAND ${PROJECT_SOURCE_DIR}/kike-gen-replies.sh
 		> kike-replies.c < ${PROJECT_SOURCE_DIR}/kike-replies
 	DEPENDS ${PROJECT_SOURCE_DIR}/kike-replies
 	COMMENT "Generating files from the list of server numerics")
-set_source_files_properties (${PROJECT_BINARY_DIR}/kike-replies.c
-	PROPERTIES HEADER_FILE_ONLY TRUE)
+add_custom_target (replies DEPENDS ${PROJECT_BINARY_DIR}/kike-replies.c)
 
 # Build
-add_executable (zyklonb zyklonb.c ${common_sources} ${common_headers})
-target_link_libraries (zyklonb ${project_libraries})
-add_threads (zyklonb)
+foreach (name zyklonb degesch kike)
+	add_executable (${name} ${name}.c ${PROJECT_BINARY_DIR}/config.h)
+	target_link_libraries (${name} ${project_libraries})
+	add_threads (${name})
+endforeach ()
 
-add_executable (degesch degesch.c kike-replies.c
-	${common_sources} ${common_headers})
-target_link_libraries (degesch ${project_libraries} ${degesch_libraries})
-add_threads (degesch)
-
-add_executable (kike kike.c kike-replies.c ${common_sources} ${common_headers})
-target_link_libraries (kike ${project_libraries})
-add_threads (kike)
+add_dependencies (kike replies)
+add_dependencies (degesch replies)
+target_link_libraries (degesch ${degesch_libraries})
 
 # Tests
-function (make_tests_for target_name)
-	get_target_property (sources   ${target_name} SOURCES)
-	get_target_property (libraries ${target_name} LINK_LIBRARIES)
-	get_target_property (options   ${target_name} COMPILE_OPTIONS)
-
-	set (test test-${target_name})
-	add_executable (${test} ${sources})
-	target_link_libraries (${test} ${libraries})
-	set_target_properties (${test} PROPERTIES
-		COMPILE_DEFINITIONS TESTING
-		COMPILE_OPTIONS "${options}")
-
-	add_test (NAME ${test} COMMAND ${test})
-endfunction (make_tests_for)
-
 include (CTest)
 if (BUILD_TESTING)
-	make_tests_for (degesch)
+	add_executable (test-degesch $<TARGET_PROPERTY:degesch,SOURCES>)
+	set_target_properties (test-degesch PROPERTIES COMPILE_DEFINITIONS TESTING)
+	target_link_libraries (test-degesch $<TARGET_PROPERTY:degesch,LINK_LIBRARIES>)
+	add_threads (test-degesch)
+	add_dependencies (test-degesch replies)
+
+	add_test (NAME test-degesch COMMAND test-degesch)
 	add_test (NAME custom-static-analysis
 		COMMAND ${PROJECT_SOURCE_DIR}/test-static)
-endif (BUILD_TESTING)
+endif ()
 
 # Various clang-based diagnostics, loads of fake positives and spam
 file (GLOB clang_tidy_sources *.c)
@@ -201,26 +185,29 @@ add_custom_target (clang-tidy
 # Installation
 install (TARGETS zyklonb degesch kike DESTINATION ${CMAKE_INSTALL_BINDIR})
 install (FILES LICENSE DESTINATION ${CMAKE_INSTALL_DOCDIR})
+# XXX: our defaults for XDG_DATA_DIRS expect /usr/local/shore or /usr/share
 install (DIRECTORY plugins/zyklonb/
-	DESTINATION ${zyklonb_plugin_dir} USE_SOURCE_PERMISSIONS)
+	DESTINATION ${CMAKE_INSTALL_DATADIR}/zyklonb/plugins USE_SOURCE_PERMISSIONS)
 install (DIRECTORY plugins/degesch/
 	DESTINATION ${CMAKE_INSTALL_DATADIR}/degesch/plugins)
 
-# Generate documentation from program help
-find_program (HELP2MAN_EXECUTABLE help2man)
-if (NOT HELP2MAN_EXECUTABLE)
-	message (FATAL_ERROR "help2man not found")
-endif (NOT HELP2MAN_EXECUTABLE)
+# Generate documentation from text markup
+find_program (ASCIIDOCTOR_EXECUTABLE asciidoctor)
+if (NOT ASCIIDOCTOR_EXECUTABLE)
+	message (FATAL_ERROR "asciidoctor not found")
+endif ()
 
 foreach (page zyklonb degesch kike)
 	set (page_output "${PROJECT_BINARY_DIR}/${page}.1")
 	list (APPEND project_MAN_PAGES "${page_output}")
 	add_custom_command (OUTPUT ${page_output}
-		COMMAND ${HELP2MAN_EXECUTABLE} -N
-			"${PROJECT_BINARY_DIR}/${page}" -o ${page_output}
-		DEPENDS ${page}
+		COMMAND ${ASCIIDOCTOR_EXECUTABLE} -b manpage
+			-a release-version=${project_version}
+			"${PROJECT_SOURCE_DIR}/${page}.adoc"
+			-o "${page_output}"
+		DEPENDS ${page}.adoc
 		COMMENT "Generating man page for ${page}" VERBATIM)
-endforeach (page)
+endforeach ()
 
 add_custom_target (docs ALL DEPENDS ${project_MAN_PAGES})
 
@@ -228,13 +215,13 @@ foreach (page ${project_MAN_PAGES})
 	string (REGEX MATCH "\\.([0-9])$" manpage_suffix "${page}")
 	install (FILES "${page}"
 		DESTINATION "${CMAKE_INSTALL_MANDIR}/man${CMAKE_MATCH_1}")
-endforeach (page)
+endforeach ()
 
 # CPack
 set (CPACK_PACKAGE_DESCRIPTION_SUMMARY "Experimental IRC client, daemon and bot")
 set (CPACK_PACKAGE_VERSION "${project_version_safe}")
-set (CPACK_PACKAGE_VENDOR "Premysl Janouch")
-set (CPACK_PACKAGE_CONTACT "Přemysl Janouch <p@janouch.name>")
+set (CPACK_PACKAGE_VENDOR "Premysl Eric Janouch")
+set (CPACK_PACKAGE_CONTACT "Přemysl Eric Janouch <p@janouch.name>")
 set (CPACK_RESOURCE_FILE_LICENSE "${PROJECT_SOURCE_DIR}/LICENSE")
 
 set (CPACK_GENERATOR "TGZ;ZIP")

LICENSE

@@ -1,4 +1,4 @@
-Copyright (c) 2014 - 2018, Přemysl Janouch <p@janouch.name>
+Copyright (c) 2014 - 2020, 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

@@ -1,3 +1,44 @@
+1.0.0 (2020-10-29) "We're Finally There!"
+
+ * Coming with real manual pages instead of help2man-generated stubs
+
+ * degesch: added support for more IRC colours and strike-through text (M-m x)
+
+ * degesch: now tolerating all UTF-8 messages cut off by the server
+
+ * degesch: disabled "behaviour.backlog_helper_strip_formatting" by default
+   since the relevant issue with ACS terminfo entries has been resolved
+
+ * degesch: enabled word wrapping in the backlog by default
+
+ * degesch: made the unread marker span the whole line, with a configurable
+   character; the previous behaviour can be obtained by setting it empty
+
+ * degesch: fixed the prompt not showing back up after exiting a backlog helper
+   when an external event has provoked an attempt to change it
+
+ * degesch: now watching fellow channel users' away status when the server
+   supports the away-notify capability; indicated by italicised nicknames
+
+ * degesch: added a plugin to highlight prime numbers in incoming messages
+
+ * kike: make sure an unspecified "bind_host" binds to both IPv4 and IPv6
+
+ * ZyklonB: install plugins to /usr/share and look for them in XDG data dirs
+
+ * Miscellaneous little fixes
+
+
+0.9.8 (2020-09-02) "Yep, Still Using It"
+
+ * degesch: fixed a crash and prompt attribute output in libedit 20191231-3.1,
+   though users are officially discouraged from using this library
+
+ * degesch: fixed Lua 5.4 build, so far the support is experimental
+
+ * Miscellaneous little fixes
+
+
 0.9.7 (2018-10-21) "Business as Usual"
 
  * kike: fix wildcard handling in WHOIS

README.adoc

@@ -52,8 +52,9 @@ Not supported:
    be used to implement this feature if needed
  - limits of almost any kind, just connections and mode `+l`
 
-This program has been https://git.janouch.name/p/haven/src/branch/master/hid[
-ported to Go], and development continues over there.
+This program has been
+https://git.janouch.name/p/haven/src/branch/master/hid[ported to Go],
+and development continues over there.
 
 ZyklonB
 -------
@@ -75,11 +76,14 @@ a package with the latest development version from Archlinux's AUR.
 
 Building
 --------
-Build dependencies: CMake, pkg-config, help2man, awk, sh, liberty (included) +
+Build dependencies: CMake, pkg-config, asciidoctor, awk, liberty (included) +
 Runtime dependencies: openssl +
 Additionally for degesch: curses, libffi, lua >= 5.3 (optional),
                           readline >= 6.0 or libedit >= 2013-07-12
 
+Avoid libedit if you can, in general it works but at the moment history is
+acting up and I have no clue about fixing it.
+
  $ git clone --recursive https://git.janouch.name/p/uirc3.git
  $ mkdir uirc3/build
  $ cd uirc3/build
@@ -129,6 +133,7 @@ Custom Key Bindings in degesch
 ------------------------------
 The default and preferred frontend used in 'degesch' is GNU Readline.  This
 means that you can change your bindings by editing '~/.inputrc'.  For example:
+
 ....
 # Preload with system-wide settings
 $include /etc/inputrc
@@ -139,6 +144,7 @@ $if degesch
 "\e\e[D": move-buffer-left
 $endif
 ....
+
 Consult the source code and the GNU Readline manual for a list of available
 functions.  Also refer to the latter for the exact syntax of this file.
 Beware that you can easily break the program if you're not careful.
@@ -151,15 +157,14 @@ want to depend on UTF-8 or 256color terminals in the code.  In addition to that,
 I appear to be one of the few people who use black on white terminals.
 
  /set behaviour.date_change_line = "%a %e %b %Y"
- /set behaviour.plugin_autoload += "fancy-prompt.lua,thin-cursor.lua"
+ /set behaviour.plugin_autoload += "fancy-prompt.lua"
  /set behaviour.backlog_helper = "LESSSECURE=1 less -R +Gb -Ps'Backlog ?ltlines %lt-%lb?L/%L. .?e(END):?pB%pB\\%..'"
- /set behaviour.backlog_helper_strip_formatting = off
- /set attributes.reset = "\x1b[0m"
  /set attributes.userhost = "\x1b[38;5;109m"
  /set attributes.join = "\x1b[38;5;108m"
  /set attributes.part = "\x1b[38;5;138m"
  /set attributes.external = "\x1b[38;5;248m"
  /set attributes.timestamp = "\x1b[48;5;255m\x1b[38;5;250m"
+ /set attributes.read_marker = "\x1b[38;5;202m"
 
 Configuration profiles
 ----------------------
@@ -185,5 +190,5 @@ License
 This software is released under the terms of the 0BSD license, the text of which
 is included within the package along with the list of authors.
 
-Note that 'degesch' technically becomes GPL-licensed when you statically link it
-against GNU Readline, but that is not a concern of this source package.
+Note that 'degesch' becomes GPL-licensed when you link it against GNU Readline
+but that is not a concern of this source package.  The licenses are compatible.

common.c

@@ -1,7 +1,7 @@
 /*
  * common.c: common functionality
  *
- * Copyright (c) 2014 - 2015, Přemysl Janouch <p@janouch.name>
+ * Copyright (c) 2014 - 2020, 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.
@@ -50,11 +50,28 @@ init_openssl (void)
 
 // --- To be moved to liberty --------------------------------------------------
 
-static void
-cstr_set (char **s, char *new)
+// FIXME: in xssl_get_error() we rely on error reasons never being NULL (i.e.,
+//   all loaded), which isn't very robust.
+// TODO: check all places where this is used and see if we couldn't gain better
+//   information by piecing together some other subset of data from the error
+//   stack.  Most often, this is used in an error_set() context, which would
+//   allow us to allocate memory instead of returning static strings.
+static const char *
+xerr_describe_error (void)
 {
-	free (*s);
-	*s = new;
+	unsigned long err = ERR_get_error ();
+	if (!err)
+		return "undefined error";
+
+	const char *reason = ERR_reason_error_string (err);
+	do
+		// Not thread-safe, not a concern right now--need a buffer
+		print_debug ("%s", ERR_error_string (err, NULL));
+	while ((err = ERR_get_error ()));
+
+	if (!reason)
+		return "cannot retrieve error description";
+	return reason;
 }
 
 static ssize_t
@@ -81,51 +98,6 @@ unixtime_msec (long *msec)
         return tp.tv_sec;
 }
 
-/// This differs from the non-unique version in that we expect the filename
-/// to be something like a pattern for mkstemp(), so the resulting path can
-/// reside in a system-wide directory with no risk of a conflict.
-static char *
-resolve_relative_runtime_unique_filename (const char *filename)
-{
-	const char *runtime_dir = getenv ("XDG_RUNTIME_DIR");
-	const char *tmpdir = getenv ("TMPDIR");
-
-	struct str path = str_make ();
-	if (runtime_dir && *runtime_dir == '/')
-		str_append (&path, runtime_dir);
-	else if (tmpdir && *tmpdir == '/')
-		str_append (&path, tmpdir);
-	else
-		str_append (&path, "/tmp");
-	str_append_printf (&path, "/%s/%s", PROGRAM_NAME, filename);
-
-	// Try to create the file's ancestors;
-	// typically the user will want to immediately create a file in there
-	const char *last_slash = strrchr (path.str, '/');
-	if (last_slash && last_slash != path.str)
-	{
-		char *copy = xstrndup (path.str, last_slash - path.str);
-		(void) mkdir_with_parents (copy, NULL);
-		free (copy);
-	}
-	return str_steal (&path);
-}
-
-static bool
-xwrite (int fd, const char *data, size_t len, struct error **e)
-{
-	size_t written = 0;
-	while (written < len)
-	{
-		ssize_t res = write (fd, data + written, len - written);
-		if (res >= 0)
-			written += res;
-		else if (errno != EINTR)
-			return error_set (e, "%s", strerror (errno));
-	}
-	return true;
-}
-
 // --- Logging -----------------------------------------------------------------
 
 static void

config.h.in

@@ -2,7 +2,6 @@
 #define CONFIG_H
 
 #define PROGRAM_VERSION "${project_version}"
-#define ZYKLONB_PLUGIN_DIR "${CMAKE_INSTALL_PREFIX}/${zyklonb_plugin_dir}"
 
 #cmakedefine HAVE_READLINE
 #cmakedefine HAVE_EDITLINE

degesch.adoc

@@ -0,0 +1,127 @@
+degesch(1)
+==========
+:doctype: manpage
+:manmanual: uirc3 Manual
+:mansource: uirc3 {release-version}
+
+Name
+----
+degesch - an experimental IRC client
+
+Synopsis
+--------
+*degesch* [_OPTION_]...
+
+Description
+-----------
+*degesch* is a scriptable IRC client for the command line.  On the first run
+it will welcome you with an introductory message.  Should you ever get lost,
+use the */help* command to obtain more information on commands or options.
+
+Options
+-------
+*-f*, *--format*::
+	Format IRC text from the standard input, converting colour sequences and
+	other formatting marks to ANSI codes retrieved from the *terminfo*(5)
+	database:
++
+```
+printf '\x02bold\x02\n' | degesch -f
+```
++
+This feature may be used to preview server MOTD files.
+
+*-h*, *--help*::
+	Display a help message and exit.
+
+*-V*, *--version*::
+	Output version information and exit.
+
+Key bindings
+------------
+Most key bindings are inherited from the frontend in use, which is either GNU
+Readline or BSD editline.  A few of them, however, are special to the IRC client
+or assume a different function.  This is a list of all local overrides and
+their respective function names:
+
+*M-p*::
+	Go up in history for this buffer (normally mapped to *C-p*).
+*M-n*::
+	Go down in history for this buffer (normally mapped to *C-n*).
+*C-p*, *F5*: *previous-buffer*::
+	Switch to the previous buffer in order.
+*C-n*, *F6*: *next-buffer*::
+	Switch to the next buffer in order.
+*M-TAB*: *switch-buffer*::
+	Switch to the last buffer, i.e., the one you were in before.
+*M-0*, *M-1*, ..., *M-9*: *goto-buffer*::
+	Go to the N-th buffer (normally sets a repeat counter).
+	Since there is no buffer number zero, *M-0* goes to the tenth one.
+*M-!*: *goto-highlight*::
+	Go to the first following buffer with an unseen highlight.
+*M-a*: *goto-activity*::
+	Go to the first following buffer with unseen activity.
+*PageUp*: *display-backlog*::
+	Show the in-memory backlog for this buffer in the backlog helper,
+	which is almost certainly the *less*(1) program.
+*M-h*: *display-full-log*::
+	Show the log file for this buffer in the backlog helper.
+*M-H*: *toggle-unimportant*::
+	Hide all join, part and quit messages, as well as all channel mode changes
+	that only relate to user channel modes.  Intended to reduce noise in
+	channels with lots of people.
+*M-e*: *edit-input*::
+	Run an editor on the command line, making it easy to edit multiline
+	messages.  Remember to save the file before exit.
+*M-m*: *insert-attribute*::
+	The next key will be interpreted as a formatting mark to insert:
+	*c* for colours (optionally followed by numbers for the foreground
+	and background), *i* for italics, *b* for bold text, *u* for underlined,
+	*x* for struck-through, *v* for inverse text and *o* resets all formatting.
+*C-l*: *redraw-screen*::
+	Should there be any issues with the display, this will clear the terminal
+	screen and redraw all information.
+
+Additionally, *C-w* and *C-u* in editline behave the same as they would in
+Readline or the "vi" command mode, even though the "emacs" mode is enabled
+by default.
+
+Bindings can be customized in your _.inputrc_ or _.editrc_ file.  Both libraries
+support conditional execution based on the program name.  Beware that it is easy
+to make breaking changes.
+
+Environment
+-----------
+*VISUAL*, *EDITOR*::
+	The editor program to be launched by the *edit-input* function.
+	If neither variable is set, it defaults to *vi*(1).
+
+Files
+-----
+*degesch* follows the XDG Base Directory Specification.
+
+_~/.config/degesch/degesch.conf_::
+	The program's configuration file.  Preferrably use internal facilities, such
+	as the */set* command, to make changes in it.
+
+_~/.local/share/degesch/logs/_::
+	When enabled by *behaviour.logging*, log files are stored here.
+
+_~/.local/share/degesch/plugins/_::
+_/usr/local/share/degesch/plugins/_::
+_/usr/share/degesch/plugins/_::
+	Plugins are searched for in these directories, in order.
+
+Bugs
+----
+The editline (libedit) frontend is more of a proof of concept that mostly seems
+to work but exhibits bugs that are not our fault.
+
+Reporting bugs
+--------------
+Use https://git.janouch.name/p/uirc3 to report bugs, request features,
+or submit pull requests.
+
+See also
+--------
+*less*(1), *readline*(3) or *editline*(7)

kike.adoc

@@ -0,0 +1,53 @@
+kike(1)
+=======
+:doctype: manpage
+:manmanual: uirc3 Manual
+:mansource: uirc3 {release-version}
+
+Name
+----
+kike - an experimental IRC daemon
+
+Synopsis
+--------
+*kike* [_OPTION_]...
+
+Description
+-----------
+*kike* is a basic IRC daemon for single-server networks, suitable for testing
+and private use.  When run without a configuration file, it will start listening
+on the standard port 6667 and the "any" address.
+
+Options
+-------
+*-d*, *--debug*::
+	Do not daemonize, print more information on the standard error stream
+	to help debug various issues.
+
+*-h*, *--help*::
+	Display a help message and exit.
+
+*-V*, *--version*::
+	Output version information and exit.
+
+*--write-default-cfg*[**=**__PATH__]::
+	Write a configuration file with defaults, show its path and exit.
++
+The file will be appropriately commented.
++
+When no _PATH_ is specified, it will be created in the user's home directory,
+contrary to what you might expect from a server.
+
+Files
+-----
+*kike* follows the XDG Base Directory Specification.
+
+_~/.config/kike/kike.conf_::
+_/etc/xdg/kike/kike.conf_::
+	The daemon's configuration file.  Use the *--write-default-cfg* option
+	to create a new one for editing.
+
+Reporting bugs
+--------------
+Use https://git.janouch.name/p/uirc3 to report bugs, request features,
+or submit pull requests.

kike.c

@@ -1,7 +1,7 @@
 /*
  * kike.c: the experimental IRC daemon
  *
- * Copyright (c) 2014 - 2018, Přemysl Janouch <p@janouch.name>
+ * Copyright (c) 2014 - 2020, 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.
@@ -47,7 +47,7 @@ static struct simple_config_item g_config_table[] =
 	{ "tls_key",         NULL,              "Server TLS private key (PEM)"   },
 	{ "tls_ciphers",     DEFAULT_CIPHERS,   "OpenSSL cipher list"            },
 
-	{ "operators",       NULL,              "IRCop TLS cert. fingerprints"   },
+	{ "operators",       NULL, "IRCop TLS client cert. SHA-1 fingerprints"   },
 
 	{ "max_connections", "0",               "Global connection limit"        },
 	{ "ping_interval",   "180",             "Interval between PINGs (sec)"   },
@@ -3061,8 +3061,8 @@ irc_try_read (struct client *c)
 	while (true)
 	{
 		str_reserve (buf, 512);
-		n_read = recv (c->socket_fd, buf->str + buf->len,
-			buf->alloc - buf->len - 1 /* null byte */, 0);
+		n_read = read (c->socket_fd, buf->str + buf->len,
+			buf->alloc - buf->len - 1 /* null byte */);
 
 		if (n_read > 0)
 		{
@@ -3082,7 +3082,7 @@ irc_try_read (struct client *c)
 		if (errno == EINTR)
 			continue;
 
-		print_debug ("%s: %s: %s", __func__, "recv", strerror (errno));
+		print_debug ("%s: %s: %s", __func__, "read", strerror (errno));
 		client_kill (c, strerror (errno));
 		return false;
 	}
@@ -3137,7 +3137,7 @@ irc_try_write (struct client *c)
 
 	while (buf->len)
 	{
-		n_written = send (c->socket_fd, buf->str, buf->len, 0);
+		n_written = write (c->socket_fd, buf->str, buf->len);
 		if (n_written >= 0)
 		{
 			str_remove_slice (buf, 0, n_written);
@@ -3149,7 +3149,7 @@ irc_try_write (struct client *c)
 		if (errno == EINTR)
 			continue;
 
-		print_debug ("%s: %s: %s", __func__, "send", strerror (errno));
+		print_debug ("%s: %s: %s", __func__, "write", strerror (errno));
 		client_kill (c, strerror (errno));
 		return false;
 	}
@@ -3261,7 +3261,7 @@ error_ssl_3:
 	SSL_free (c->ssl);
 	c->ssl = NULL;
 error_ssl_2:
-	error_info = ERR_reason_error_string (ERR_get_error ());
+	error_info = xerr_describe_error ();
 error_ssl_1:
 	print_debug ("could not initialize TLS for %s: %s", c->address, error_info);
 	return false;
@@ -3540,7 +3540,7 @@ irc_initialize_ssl_ctx (struct server_context *ctx,
 	if (!ctx->ssl_ctx)
 	{
 		error_set (e, "%s: %s", "could not initialize TLS",
-			ERR_reason_error_string (ERR_get_error ()));
+			xerr_describe_error ());
 		return false;
 	}
 	SSL_CTX_set_verify (ctx->ssl_ctx,
@@ -3570,11 +3570,11 @@ irc_initialize_ssl_ctx (struct server_context *ctx,
 		error_set (e, "failed to select any cipher from the cipher list");
 	else if (!SSL_CTX_use_certificate_chain_file (ctx->ssl_ctx, cert_path))
 		error_set (e, "%s: %s", "setting the TLS certificate failed",
-			ERR_reason_error_string (ERR_get_error ()));
+			xerr_describe_error ());
 	else if (!SSL_CTX_use_PrivateKey_file
 		(ctx->ssl_ctx, key_path, SSL_FILETYPE_PEM))
 		error_set (e, "%s: %s", "setting the TLS private key failed",
-			ERR_reason_error_string (ERR_get_error ()));
+			xerr_describe_error ());
 	else
 		// TODO: SSL_CTX_check_private_key()?  It has probably already been
 		//   checked by SSL_CTX_use_PrivateKey_file() above.
@@ -3680,26 +3680,35 @@ irc_initialize_motd (struct server_context *ctx, struct error **e)
 	return true;
 }
 
+static bool
+irc_parse_config_unsigned (const char *name, const char *value, unsigned *out,
+	unsigned long min, unsigned long max, struct error **e)
+{
+	unsigned long ul;
+	hard_assert (value != NULL);
+	if (!xstrtoul (&ul, value, 10) || ul > max || ul < min)
+	{
+		error_set (e, "invalid configuration value for `%s': %s",
+			name, "the number is invalid or out of range");
+		return false;
+	}
+	*out = ul;
+	return true;
+}
+
 /// This function handles values that require validation before their first use,
 /// or some kind of a transformation (such as conversion to an integer) needs
 /// to be done before they can be used directly.
 static bool
 irc_parse_config (struct server_context *ctx, struct error **e)
 {
-	unsigned long ul;
 #define PARSE_UNSIGNED(name, min, max)                                         \
-	const char *name = str_map_find (&ctx->config, #name);                     \
-	hard_assert (name != NULL);                                                \
-	if (!xstrtoul (&ul, name, 10) || ul > max || ul < min)                     \
-	{                                                                          \
-		error_set (e, "invalid configuration value for `%s': %s",              \
-			#name, "the number is invalid or out of range");                   \
-		return false;                                                          \
-	}                                                                          \
-	ctx->name = ul
+	irc_parse_config_unsigned (#name, str_map_find (&ctx->config, #name),      \
+		&ctx->name, min, max, e)
 
-	PARSE_UNSIGNED (ping_interval,   1, UINT_MAX);
-	PARSE_UNSIGNED (max_connections, 0, UINT_MAX);
+	if (!PARSE_UNSIGNED (ping_interval,   1, UINT_MAX)
+	 || !PARSE_UNSIGNED (max_connections, 0, UINT_MAX))
+		return false;
 
 	bool result = true;
 	struct strv fingerprints = strv_make ();
@@ -3792,6 +3801,14 @@ irc_listen (struct addrinfo *gai_iter)
 	soft_assert (setsockopt (fd, SOL_SOCKET, SO_REUSEADDR,
 		&yes, sizeof yes) != -1);
 
+#if defined SOL_IPV6 && defined IPV6_V6ONLY
+	// Make NULL always bind to both IPv4 and IPv6, irrespectively of the order
+	// of results; only INADDR6_ANY seems to be affected by this
+	if (gai_iter->ai_family == AF_INET6)
+		soft_assert (setsockopt (fd, SOL_IPV6, IPV6_V6ONLY,
+			&yes, sizeof yes) != -1);
+#endif
+
 	char host[NI_MAXHOST], port[NI_MAXSERV];
 	host[0] = port[0] = '\0';
 	int err = getnameinfo (gai_iter->ai_addr, gai_iter->ai_addrlen,
@@ -3846,7 +3863,6 @@ irc_listen_resolve (struct server_context *ctx,
 
 		ctx->listen_fds[ctx->n_listen_fds++] = fd;
 		poller_fd_set (event, POLLIN);
-		break;
 	}
 	freeaddrinfo (gai_result);
 }

plugins/degesch/auto-rejoin.lua

@@ -1,7 +1,7 @@
 --
 -- auto-rejoin.lua: join back automatically when someone kicks you
 --
--- Copyright (c) 2016, Přemysl Janouch <p@janouch.name>
+-- Copyright (c) 2016, 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.

plugins/degesch/censor.lua

@@ -1,7 +1,7 @@
 --
 -- censor.lua: black out certain users' messages
 --
--- Copyright (c) 2016, Přemysl Janouch <p@janouch.name>
+-- Copyright (c) 2016, 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.
@@ -49,7 +49,7 @@ degesch.setup_config {
 
 local censor = function (line)
 	-- Taking a shortcut to avoid lengthy message reassembly
-	local start, text = line:match ("^(.- PRIVMSG .-:)(.*)$")
+	local start, text = line:match ("^(.- PRIVMSG .- :)(.*)$")
 	local ctcp, rest = text:match ("^(\x01%g+ )(.*)")
 	text = ctcp and ctcp .. "\x0301,01" .. rest or "\x0301,01" .. text
 	return start .. text

plugins/degesch/fancy-prompt.lua

@@ -1,7 +1,7 @@
 --
 -- fancy-prompt.lua: the fancy multiline prompt you probably want
 --
--- Copyright (c) 2016, Přemysl Janouch <p@janouch.name>
+-- Copyright (c) 2016, 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.

plugins/degesch/last-fm.lua

@@ -5,7 +5,7 @@
 --
 -- I call this style closure-oriented programming
 --
--- Copyright (c) 2016, Přemysl Janouch <p@janouch.name>
+-- Copyright (c) 2016, 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.

plugins/degesch/ping-timeout.lua

@@ -1,7 +1,7 @@
 --
 -- ping-timeout.lua: ping timeout readability enhancement plugin
 --
--- Copyright (c) 2015 - 2016, Přemysl Janouch <p@janouch.name>
+-- Copyright (c) 2015 - 2016, 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.

plugins/degesch/prime.lua

@@ -0,0 +1,68 @@
+--
+-- prime.lua: highlight prime numbers in messages
+--
+-- Copyright (c) 2020, 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.
+--
+
+local smallest, highlight = 0, "\x1f"
+degesch.setup_config {
+	smallest = {
+		type = "integer",
+		default = "0",
+		comment = "smallest number to scan for primality",
+		on_change = function (v) smallest = math.max (v, 2) end
+	},
+	highlight = {
+		type = "string",
+		default = "\"\\x1f\"",
+		comment = "the attribute to use for highlights",
+		on_change = function (v) highlight = v end
+	},
+}
+
+-- The prime test is actually very fast, so there is no DoS concern
+local do_intercolour = function (text)
+	return tostring (text:gsub ("%f[%w_]%d+", function (n)
+		if tonumber (n) < smallest then return nil end
+		for i = 2, n ^ (1 / 2) do if (n % i) == 0 then return nil end end
+		return highlight .. n .. highlight
+	end))
+end
+
+local do_interlink = function (text)
+	local rebuilt, last = {""}, 1
+	for start in text:gmatch ('()\x03') do
+		table.insert (rebuilt, do_intercolour (text:sub (last, start - 1)))
+		local sub = text:sub (start + 1)
+		last = start + (sub:match ('^%d%d?,%d%d?()') or sub:match ('^%d?%d?()'))
+		table.insert (rebuilt, text:sub (start, last - 1))
+	end
+	return table.concat (rebuilt) .. do_intercolour (text:sub (last))
+end
+
+local do_message = function (text)
+	local rebuilt, last = {""}, 1
+	for run, link, endpos in text:gmatch ('(.-)(%f[%g]https?://%g+)()') do
+		last = endpos
+		table.insert (rebuilt, do_interlink (run) .. link)
+	end
+	return table.concat (rebuilt) .. do_interlink (text:sub (last))
+end
+
+-- XXX: sadly it won't typically highlight primes in our own messages,
+-- unless IRCv3 echo-message is on
+degesch.hook_irc (function (hook, server, line)
+	local start, message = line:match ("^(.- PRIVMSG .- :)(.*)$")
+	return message and start .. do_message (message) or line
+end)

plugins/degesch/slack.lua

@@ -1,7 +1,7 @@
 --
 -- slack.lua: try to fix up UX when using the Slack IRC gateway
 --
--- Copyright (c) 2017, Přemysl Janouch <p@janouch.name>
+-- Copyright (c) 2017, 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.
@@ -91,7 +91,7 @@ end)
 degesch.hook_irc (function (hook, server, line)
 	if not servers[server.name] then return line end
 	if unemojify then
-		local start, text = line:match ("^(.- PRIVMSG .-:)(.*)$")
+		local start, text = line:match ("^(.- PRIVMSG .- :)(.*)$")
 		if start then return start .. text:gsub (":([a-z_]+):", function (name)
 			if emoji[name] then return emoji[name] end
 			return ":" .. name .. ":"

plugins/degesch/thin-cursor.lua

@@ -1,7 +1,7 @@
 --
 -- thin-cursor.lua: set a thin cursor
 --
--- Copyright (c) 2016, Přemysl Janouch <p@janouch.name>
+-- Copyright (c) 2016, 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.

plugins/degesch/utm-filter.lua

@@ -1,7 +1,7 @@
 --
 -- utm-filter.lua: filter out Google Analytics bullshit from URLs
 --
--- Copyright (c) 2015, Přemysl Janouch <p@janouch.name>
+-- Copyright (c) 2015, 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.

plugins/zyklonb/calc

@@ -2,7 +2,7 @@
 
   ZyklonB calc plugin, basic Scheme evaluator
 
-  Copyright 2016 Přemysl Janouch
+  Copyright 2016 Přemysl Eric Janouch
   See the file LICENSE for licensing information.
 
 !#

plugins/zyklonb/coin

@@ -2,7 +2,7 @@
 #
 # ZyklonB coin plugin, random number-based utilities
 #
-# Copyright 2012, 2014 Přemysl Janouch
+# Copyright 2012, 2014 Přemysl Eric Janouch
 # See the file LICENSE for licensing information.
 #
 

plugins/zyklonb/eval

@@ -2,7 +2,7 @@
 #
 # ZyklonB eval plugin, LISP-like expression evaluator
 #
-# Copyright 2013, 2014 Přemysl Janouch
+# Copyright 2013, 2014 Přemysl Eric Janouch
 # See the file LICENSE for licensing information.
 #
 

plugins/zyklonb/factoids

@@ -2,7 +2,7 @@
 #
 # ZyklonB factoids plugin
 #
-# Copyright 2016 Přemysl Janouch <p@janouch.name>
+# Copyright 2016 Přemysl Eric Janouch <p@janouch.name>
 # See the file LICENSE for licensing information.
 #
 

plugins/zyklonb/pomodoro

@@ -3,7 +3,7 @@
 #
 # ZyklonB pomodoro plugin
 #
-# Copyright 2015 Přemysl Janouch
+# Copyright 2015 Přemysl Eric Janouch
 # See the file LICENSE for licensing information.
 #
 

plugins/zyklonb/script

@@ -2,7 +2,7 @@
 //
 // ZyklonB scripting plugin, using a custom stack-based language
 //
-// Copyright 2014 Přemysl Janouch
+// Copyright 2014 Přemysl Eric Janouch
 // See the file LICENSE for licensing information.
 //
 // Just compile this file as usual (sans #!) if you don't feel like using TCC.

plugins/zyklonb/seen

@@ -2,7 +2,7 @@
 --
 -- ZyklonB seen plugin
 --
--- Copyright 2016 Přemysl Janouch <p@janouch.name>
+-- Copyright 2016 Přemysl Eric Janouch <p@janouch.name>
 -- See the file LICENSE for licensing information.
 --
 

plugins/zyklonb/youtube

@@ -2,7 +2,7 @@
 #
 # ZyklonB YouTube plugin, displaying info about YouTube links
 #
-# Copyright 2014 - 2015, Přemysl Janouch <p@janouch.name>
+# Copyright 2014 - 2015, Přemysl Eric Janouch <p@janouch.name>
 # See the file LICENSE for licensing information.
 #
 

zyklonb.adoc

@@ -0,0 +1,104 @@
+zyklonb(1)
+==========
+:doctype: manpage
+:manmanual: uirc3 Manual
+:mansource: uirc3 {release-version}
+
+Name
+----
+zyklonb - an experimental IRC bot
+
+Synopsis
+--------
+*zyklonb* [_OPTION_]...
+
+Description
+-----------
+*zyklonb* is a modular IRC bot with a programming language-agnostic plugin
+architecture based on co-processes.
+
+Options
+-------
+*-d*, *--debug*::
+	Print more information to help debug various issues.
+
+*-h*, *--help*::
+	Display a help message and exit.
+
+*-V*, *--version*::
+	Output version information and exit.
+
+*--write-default-cfg*[**=**__PATH__]::
+	Write a configuration file with defaults, show its path and exit.
++
+The file will be appropriately commented.
+
+Commands
+--------
+The bot accepts the following commands when they either appear quoted by the
+*prefix* string on a channel or unquoted as a private message sent directly
+to the bot, on the condition that the sending user matches the *admin*
+regular expression or that it is left unset:
+
+*quote* [_message_]::
+	Forwards the message to the IRC server as-is.
+*quit* [_reason_]::
+	Quits the IRC server, with an optional reason string.
+*status*::
+	Sends back a report about its state and all loaded plugins.
+*load* _plugin_[, _plugin_]...::
+	Tries to load the given plugins.
+*unload* _plugin_[, _plugin_]...::
+	Tries to unload the given plugins.
+*reload* _plugin_[, _plugin_]...::
+	The same as *unload* immediately followed by *load*.
+
+Plugins
+-------
+Plugins communicate with the bot over their standard input and output streams
+using the IRC protocol.  (Caveat: the standard C library doesn't automatically
+flush FILE streams for pipes on newlines.)  A special *ZYKLONB* command is
+introduced for RPC, with the following subcommands:
+
+*ZYKLONB get_config* _key_::
+	Request the value of the given configuration option.  If no such option
+	exists, the value will be empty.  The response will be delivered in
+	the following format:
++
+```
+ZYKLONB :value
+```
++
+This is particularly useful for retrieving the *prefix* string.
+
+*ZYKLONB print* _message_::
+	Make the bot print the _message_ on its standard output.
+
+*ZYKLONB register*::
+	Once a plugin issues this command, it will start receiving all of the bot's
+	incoming IRC traffic, which includes data from the initialization period.
+
+All other commands will be forwarded directly to the IRC server.
+
+Files
+-----
+*zyklonb* follows the XDG Base Directory Specification.
+
+_~/.config/zyklonb/zyklonb.conf_::
+	The bot's configuration file.  Use the *--write-default-cfg* option
+	to create a new one for editing.
+
+_~/.local/share/zyklonb/_::
+	The initial working directory for plugins, in which they may create private
+	databases or other files as needed.
+
+_~/.local/share/zyklonb/plugins/_::
+_/usr/local/share/zyklonb/plugins/_::
+_/usr/share/zyklonb/plugins/_::
+	Plugins are searched for in these directories, in order, unless
+	the *plugin_dir* configuration option overrides this.
+
+Reporting bugs
+--------------
+Use https://git.janouch.name/p/uirc3 to report bugs, request features,
+or submit pull requests.

zyklonb.c

@@ -1,7 +1,7 @@
 /*
  * zyklonb.c: the experimental IRC bot
  *
- * Copyright (c) 2014 - 2016, Přemysl Janouch <p@janouch.name>
+ * Copyright (c) 2014 - 2020, 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.
@@ -18,7 +18,6 @@
 
 #include "config.h"
 #define PROGRAM_NAME "ZyklonB"
-#define PLUGIN_DIR ZYKLONB_PLUGIN_DIR
 
 #include "common.c"
 
@@ -49,7 +48,7 @@ static struct simple_config_item g_config_table[] =
 	{ "prefix",          ":",               "The prefix for bot commands"    },
 	{ "admin",           NULL,              "Host mask for administrators"   },
 	{ "plugins",         NULL,              "The plugins to load on startup" },
-	{ "plugin_dir",      PLUGIN_DIR,        "Where to search for plugins"    },
+	{ "plugin_dir",      NULL,              "Plugin search path override"    },
 	{ "recover",         "on",              "Whether to re-launch on crash"  },
 
 	{ NULL,              NULL,              NULL                             }
@@ -280,7 +279,7 @@ irc_send (struct bot_context *ctx, const char *format, ...)
 		if (SSL_write (ctx->ssl, str.str, str.len) != (int) str.len)
 		{
 			print_debug ("%s: %s: %s", __func__, "SSL_write",
-				ERR_error_string (ERR_get_error (), NULL));
+				xerr_describe_error ());
 			result = false;
 		}
 	}
@@ -320,13 +319,13 @@ irc_initialize_ca_set (SSL_CTX *ssl_ctx, const char *file, const char *path,
 
 		return error_set (e, "%s: %s",
 			"failed to set locations for the CA certificate bundle",
-			ERR_reason_error_string (ERR_get_error ()));
+			xerr_describe_error ());
 	}
 
 	if (!SSL_CTX_set_default_verify_paths (ssl_ctx))
 		return error_set (e, "%s: %s",
 			"couldn't load the default CA certificate bundle",
-			ERR_reason_error_string (ERR_get_error ()));
+			xerr_describe_error ());
 	return true;
 }
 
@@ -407,7 +406,7 @@ irc_initialize_tls (struct bot_context *ctx, struct error **e)
 		else if (!SSL_use_certificate_file (ctx->ssl, path, SSL_FILETYPE_PEM)
 			|| !SSL_use_PrivateKey_file (ctx->ssl, path, SSL_FILETYPE_PEM))
 			print_error ("%s: %s", "setting the TLS client certificate failed",
-				ERR_error_string (ERR_get_error (), NULL));
+				xerr_describe_error ());
 		free (path);
 	}
 
@@ -434,10 +433,8 @@ error_ssl_2:
 	SSL_CTX_free (ctx->ssl_ctx);
 	ctx->ssl_ctx = NULL;
 error_ssl_1:
-	// XXX: these error strings are really nasty; also there could be
-	//   multiple errors on the OpenSSL stack.
 	if (!error_info)
-		error_info = ERR_error_string (ERR_get_error (), NULL);
+		error_info = xerr_describe_error ();
 	return error_set (e, "%s: %s", "could not initialize TLS", error_info);
 }
 
@@ -1017,21 +1014,40 @@ is_valid_plugin_name (const char *name)
 	return true;
 }
 
+static char *
+plugin_resolve_relative_filename (const char *filename)
+{
+	struct strv paths = strv_make ();
+	get_xdg_data_dirs (&paths);
+	char *result = resolve_relative_filename_generic
+		(&paths, PROGRAM_NAME "/plugins/", filename);
+	strv_free (&paths);
+	return result;
+}
+
 static struct plugin *
 plugin_launch (struct bot_context *ctx, const char *name, struct error **e)
 {
+	char *path = NULL;
 	const char *plugin_dir = str_map_find (&ctx->config, "plugin_dir");
-	if (!plugin_dir)
+	if (plugin_dir)
 	{
-		error_set (e, "plugin directory not set");
-		return NULL;
+		// resolve_relative_filename_generic() won't accept relative paths,
+		// so just keep the old behaviour and expect the file to exist.
+		// We could use resolve_filename() on "plugin_dir" with paths=getcwd().
+		path = xstrdup_printf ("%s/%s", plugin_dir, name);
+	}
+	else if (!(path = plugin_resolve_relative_filename (name)))
+	{
+		error_set (e, "plugin not found");
+		goto fail_0;
 	}
 
 	int stdin_pipe[2];
 	if (pipe (stdin_pipe) == -1)
 	{
 		error_set (e, "%s: %s", "pipe", strerror (errno));
-		return NULL;
+		goto fail_0;
 	}
 
 	int stdout_pipe[2];
@@ -1081,7 +1097,7 @@ plugin_launch (struct bot_context *ctx, const char *name, struct error **e)
 		// Restore some of the signal handling
 		signal (SIGPIPE, SIG_DFL);
 
-		char *argv[] = { xstrdup_printf ("%s/%s", plugin_dir, name), NULL };
+		char *argv[] = { path, NULL };
 		execve (argv[0], argv, environ);
 
 		// We will collect the failure later via SIGCHLD
@@ -1091,6 +1107,7 @@ plugin_launch (struct bot_context *ctx, const char *name, struct error **e)
 	}
 
 	str_free (&work_dir);
+	free (path);
 
 	xclose (stdin_pipe[0]);
 	xclose (stdout_pipe[1]);
@@ -1110,6 +1127,8 @@ fail_2:
 fail_1:
 	xclose (stdin_pipe[0]);
 	xclose (stdin_pipe[1]);
+fail_0:
+	free (path);
 	return NULL;
 }