release v0.21.3

Works around a problem where MPD goes into a busy loop because
snd_pcm_drain() always returns `-EAGAIN` without making any progress
(fixes #425).

This problem was triggered by snd_pcm_drain() after snd_pcm_cancel()
and snd_pcm_prepare(), but without submitting any data with
snd_pcm_writei().

I believe this is a kernel bug: in non-blocking mode, the kernel's
snd_pcm_drain() function returns early.  In this mode, it only checks
whether snd_pcm_drain_done() has been called already, but
snd_pcm_drain_done() is never called if no data was submitted.

In blocking mode, the following `for` loop detects this condition, so
snd_pcm_drain_done() is not necessary, but without this extra check,
we get `-EAGAIN` forever.

.gitignore

@@ -1,88 +1,8 @@
-*.Plo
-*.Po
-*.a
-*.d
-*.la
-*.lo
-*.o
-*.exe
-
 *~
 
 .#*
 .stgit*
-.deps
-.dirstamp
 
-tags
-
-/Makefile
-/Makefile.in
-/aclocal.m4
-/autom4te.cache
-/config.h
-/config.h.in
-/config.log
-/config.mk
-/config.status
-/config_detected.h
-/config_detected.mk
-/configure
-/configure.lineno
-/depmode
-/libtool
-/ltmain.sh
-/mkinstalldirs
 /output/
-/src/mpd
-/systemd/system/mpd.service
-/systemd/user/mpd.service
-/stamp-h1
-
-/src/dsd2pcm/dsd2pcm
-/src/win32/mpd_win32_rc.rc
-
-/doc/doxygen.conf
-/doc/protocol.html
-/doc/protocol
-/doc/user
-/doc/developer
-/doc/sticker
-/doc/api
-
-/test/software_volume
-/test/run_convert
-/test/run_decoder
-/test/read_tags
-/test/run_filter
-/test/run_encoder
-/test/run_output
-/test/read_conf
-/test/run_input
-/test/read_mixer
-/test/dump_playlist
-/test/run_normalize
-/test/tmp
-/test/run_inotify
-/test/test_queue_priority
-/test/test_protocol
-/test/run_ntp_server
-/test/run_resolver
-/test/run_tcp_connect
-/test/test_pcm
-/test/dump_rva2
-/test/dump_text_file
-/test/test_util
-/test/test_byte_reverse
-/test/test_mixramp
-/test/test_vorbis_encoder
-/test/DumpDatabase
-
-/lib/
-
-/*.tar.gz
-/*.tar.bz2
-/*.tar.xz
-/mpd-*/
 
 __pycache__/

NEWS

@@ -1,3 +1,40 @@
+ver 0.21.3 (2018/11/16)
+* output
+  - alsa: fix crash bug
+  - alsa: fix stuttering at start of playback
+  - alsa: fix discarded samples at end of song
+  - alsa: clear error after reopening device
+* log: default to journal if MPD was started as systemd service
+
+ver 0.21.2 (2018/11/12)
+* protocol
+  - operator "=~" matches a regular expression
+  - operator "contains" matches substrings
+* decoder
+  - ffmpeg: require FFmpeg 3.1 or later
+  - ffmpeg: fix broken sound with certain codecs
+* output
+  - alsa: fix high CPU usage with dmix
+  - httpd: fix three crash bugs
+* mixer
+  - alsa: fix more rounding errors
+* fix zlib support
+
+ver 0.21.1 (2018/11/04)
+* protocol
+  - allow escaping quotes in filter expressions
+  - operator "==" never searches substrings in filter expressions
+* decoder
+  - ffmpeg: fix build failure with non-standard FFmpeg installation path
+  - flac: fix linker failure when building without FLAC support
+* encoder
+  - vorbis: fix linker failure when building without Vorbis decoder
+* fix build failure on Linux-PowerPC
+* fix build failure on FreeBSD
+* eliminate DLL dependencies on Windows
+* add warning about buggy Boost version 1.67
+* require Meson 0.47.2 because a Meson 0.47.1 bug breaks our build
+
 ver 0.21 (2018/10/31)
 * configuration
   - add "include" directive, allows including config files

android/.gitignore

@@ -1 +0,0 @@
-/build

android/AndroidManifest.xml

@@ -2,8 +2,8 @@
 <manifest xmlns:android="http://schemas.android.com/apk/res/android"
           package="org.musicpd"
           android:installLocation="auto"
-          android:versionCode="23"
-          android:versionName="0.21">
+          android:versionCode="25"
+          android:versionName="0.21.3">
 
   <uses-sdk android:minSdkVersion="21" android:targetSdkVersion="26"/>
 

autogen.sh

@@ -1,11 +0,0 @@
-#!/bin/sh
-
-set -e
-
-rm -rf config.cache build
-mkdir build
-
-aclocal -I m4 $ACLOCAL_FLAGS
-autoheader
-automake --add-missing $AUTOMAKE_FLAGS
-autoconf

doc/.gitignore

@@ -1,2 +0,0 @@
-/html/
-/doctrees/

doc/conf.py

@@ -38,9 +38,9 @@ author = 'Max Kellermann'
 # built documents.
 #
 # The short X.Y version.
-version = '0.21'
+version = '0.21.3'
 # The full version, including alpha/beta/rc tags.
-release = '0.21~git'
+release = version
 
 # The language for content autogenerated by Sphinx. Refer to documentation
 # for a list of supported languages.

doc/mpdconf.example

@@ -32,7 +32,7 @@
 # settings.
 #
 # The special value "syslog" makes MPD use the local syslog daemon. This
-# setting defaults to logging to syslog, otherwise logging is disabled.
+# setting defaults to logging to syslog.
 #
 #log_file			"~/.mpd/log"
 #

doc/protocol.rst

@@ -8,7 +8,7 @@ General protocol syntax
 Protocol overview
 =================
 
-The ``MPD`` command protocol exchanges
+The :program:`MPD` command protocol exchanges
 line-based text records between client and server over TCP.
 Once the client is connected to the server, they conduct a
 conversation until the client closes the connection. The
@@ -152,10 +152,15 @@ of:
   ``VALUE`` in ``AlbumArtist``
   and falls back to ``Artist`` tags if
   ``AlbumArtist`` does not exist.
-  ``VALUE`` is what to find.  The
-  `find` commands specify an exact value
-  and are case-sensitive; the `search`
-  commands specify a sub string and ignore case.
+  ``VALUE`` is what to find.
+
+- ``(TAG contains 'VALUE')`` checks if the given value is a substring
+  of the tag value.
+
+- ``(TAG =~ 'VALUE')`` and ``(TAG !~ 'VALUE')`` use a Perl-compatible
+  regular expression instead of doing a simple string comparison.
+  (This feature is only available if :program:`MPD` was compiled with
+  :file:`libpcre`)
 
 - ``(file == 'VALUE')``: match the full song URI
   (relative to the music directory).
@@ -175,22 +180,58 @@ of:
   matches the audio format with the given mask (i.e. one
   or more attributes may be "*").
 
-- ``(!EXPRESSION)``: negate an expression.
+- ``(!EXPRESSION)``: negate an expression.  Note that each expression
+  must be enclosed in parantheses, e.g. :code:`(!(artist == 'VALUE'))`
+  (which is equivalent to :code:`(artist != 'VALUE')`)
 
 - ``(EXPRESSION1 AND EXPRESSION2 ...)``: combine two or
-  more expressions with logical "and".
+  more expressions with logical "and".  Note that each expression must
+  be enclosed in parantheses, e.g. :code:`((artist == 'FOO') AND
+  (album == 'BAR'))`
+
+The :command:`find` commands are case sensitive, which
+:command:`search` and related commands ignore case.
 
 Prior to MPD 0.21, the syntax looked like this::
 
  find TYPE VALUE
 
+Escaping String Values
+----------------------
+
+String values are quoted with single or double quotes, and special
+characters within those values must be escaped with the backslash
+(``\``).  Keep in mind that the backslash is also the escape character
+on the protocol level, which means you may need to use double
+backslash.
+
+Example expression which matches an artist named ``foo'bar"``::
+
+ (artist "foo\'bar\"")
+
+At the protocol level, the command must look like this::
+
+ find "(artist \"foo\\'bar\\\"\")"
+
+The double quotes enclosing the artist name must be escaped because
+they are inside a double-quoted ``find`` parameter.  The single quote
+inside that artist name must be escaped with two backslashes; one to
+escape the single quote, and another one because the backslash inside
+the string inside the parameter needs to be escaped as well.  The
+double quote has three confusing backslashes: two to build one
+backslash, and another one to escape the double quote on the protocol
+level.  Phew!
+
+To reduce confusion, you should use a library such as `libmpdclient
+<https://www.musicpd.org/libs/libmpdclient/>`_ which escapes command
+arguments for you.
+
 .. _tags:
 
 Tags
 ====
 
-The following tags are supported by
-``MPD``:
+The following tags are supported by :program:`MPD`:
 
 * **artist**: the artist name. Its meaning is not well-defined; see "*composer*" and "*performer*" for more specific tags.
 * **artistsort**: same as artist, but for sorting. This usually omits prefixes such as "The".
@@ -216,7 +257,7 @@ The following tags are supported by
 * **musicbrainz_workid**: the work id in the `MusicBrainz <https://picard.musicbrainz.org/docs/mappings/>`_ database.
 
 There can be multiple values for some of these tags.  For
-example, ``MPD`` may return multiple
+example, :program:`MPD` may return multiple
 lines with a ``performer`` tag.  A tag value is
 a UTF-8 string.
 
@@ -259,16 +300,17 @@ Recipes
 Queuing
 =======
 
-Often, users run ``MPD`` with :ref:`random <command_random>` enabled,
-but want to be able to insert songs "before" the rest of the playlist.
-That is commonly called "queuing".
+Often, users run :program:`MPD` with :ref:`random <command_random>`
+enabled, but want to be able to insert songs "before" the rest of the
+playlist.  That is commonly called "queuing".
 
-``MPD`` implements this by allowing the client to specify a "priority"
-for each song in the playlist (commands :ref:`priod <command_prio>`
-and :ref:`priodid <command_prioid>`).  A higher priority means that
-the song is going to be played before the other songs.
+:program:`MPD` implements this by allowing the client to specify a
+"priority" for each song in the playlist (commands :ref:`priod
+<command_prio>` and :ref:`priodid <command_prioid>`).  A higher
+priority means that the song is going to be played before the other
+songs.
 
-In "random" mode, ``MPD`` maintains an
+In "random" mode, :program:`MPD` maintains an
 internal randomized sequence of songs.  In this sequence,
 songs with a higher priority come first, and all songs with
 the same priority are shuffled (by default, all songs are
@@ -293,9 +335,9 @@ Command reference
    commands using song ids should be used instead of the commands
    that manipulate and control playback based on playlist
    position. Using song ids is a safer method when multiple
-   clients are interacting with ``MPD``.
+   clients are interacting with :program:`MPD`.
 
-Querying ``MPD``'s status
+Querying :program:`MPD`'s status
 ================================
 
 :command:`clearerror`
@@ -310,7 +352,7 @@ Querying ``MPD``'s status
 
 :command:`idle [SUBSYSTEMS...]` [#since_0_14]_
     Waits until there is a noteworthy change in one or more
-    of ``MPD``'s subsystems.  As soon
+    of :program:`MPD`'s subsystems.  As soon
     as there is one, it lists all changed systems in a line
     in the format ``changed:
     SUBSYSTEM``, where SUBSYSTEM is one of the
@@ -319,7 +361,7 @@ Querying ``MPD``'s status
     - ``database``: the song database has been modified after :ref:`update <command_update>`.
     - ``update``: a database update has started or finished.  If the database was modified during the update, the ``database`` event is also emitted.
     - ``stored_playlist``: a stored playlist has been modified, renamed, created or deleted
-    - ``playlist``: the current playlist has been modified
+    - ``playlist``: the queue (i.e. the current playlist) has been modified
     - ``player``: the player has been started, stopped or seeked
     - ``mixer``: the volume has been changed
     - ``output``: an audio output has been added, removed or modified (e.g. renamed, enabled or disabled)
@@ -340,11 +382,11 @@ Querying ``MPD``'s status
     to wait for events as long as mpd runs.  The
     `idle` command can be canceled by
     sending the command `noidle` (no other
-    commands are allowed). ``MPD``
+    commands are allowed). :program:`MPD`
     will then leave `idle` mode and print
     results immediately; might be empty at this time.
     If the optional ``SUBSYSTEMS`` argument
-    is used, ``MPD`` will only send
+    is used, :program:`MPD` will only send
     notifications when something changed in one of the
     specified subsytems.
 
@@ -354,19 +396,21 @@ Querying ``MPD``'s status
     Reports the current status of the player and the volume
     level.
 
-    - ``volume``: ``0-100`` or ``-1`` if the volume cannot be determined
+    - ``volume``: ``0-100`` (deprecated: ``-1`` if the volume cannot
+      be determined)
     - ``repeat``: ``0`` or ``1``
     - ``random``: ``0`` or ``1``
     - ``single`` [#since_0_15]_: ``0``, ``1``, or ``oneshot`` [#since_0_21]_
     - ``consume`` [#since_0_15]_: ``0`` or ``1``
     - ``playlist``: 31-bit unsigned integer, the playlist version number
     - ``playlistlength``: integer, the length of the playlist
-    - ``state``: ``play``, ``stop, or ``pause``
+    - ``state``: ``play``, ``stop``, or ``pause``
     - ``song``: playlist song number of the current song stopped on or playing
     - ``songid``: playlist songid of the current song stopped on or playing
     - ``nextsong`` [#since_0_15]_: playlist song number of the next song to be played
     - ``nextsongid`` [#since_0_15]_: playlist songid of the next song to be played
     - ``time``: total time elapsed (of current playing/paused song)
+      (deprecated, use ``elapsed`` instead)
     - ``elapsed`` [#since_0_16]_: Total time elapsed within the current song, but with higher resolution.
     - ``duration`` [#since_0_20]_: Duration of the current song in seconds.
     - ``bitrate``: instantaneous bitrate in kbps
@@ -377,6 +421,10 @@ Querying ``MPD``'s status
     - ``updating_db``: ``job id``
     - ``error``: if there is an error, returns message here
 
+    :program:`MPD` may omit lines which have no (known) value.  Older
+    :program:`MPD` versions used to have a "magic" value for
+    "unknown", e.g. ":samp:`volume: -1`".
+
 :command:`stats`
     Displays statistics.
 
@@ -490,8 +538,36 @@ Controlling playback
 :command:`stop`
     Stops playing.
 
-The current playlist
-====================
+The Queue
+=========
+
+.. note:: The "queue" used to be called "current playlist" or just
+          "playlist", but that was deemed confusing, because
+          "playlists" are also files containing a sequence of songs.
+          Those "playlist files" or "stored playlists" can be
+          :ref:`loaded into the queue <command_load>` and the queue
+          can be :ref:`saved into a playlist file <command_save>`, but
+          they are not to be confused with the queue.
+
+          Many of the command names in this section reflect the old
+          naming convention, but for the sake of compatibility, we
+          cannot rename commands.
+
+There are two ways to address songs within the queue: by their
+position and by their id.
+
+The position is a 0-based index.  It is unstable by design: if you
+move, delete or insert songs, all following indices will change, and a
+client can never be sure what song is behind a given index/position.
+
+Song ids on the other hand are stable: an id is assigned to a song
+when it is added, and will stay the same, no matter how much it is
+moved around.  Adding the same song twice will assign different ids to
+them, and a deleted-and-readded song will have a new id.  This way, a
+client can always be sure the correct song is being used.
+
+Many commands come in two flavors, one for each address type.
+Whenever possible, ids should be used.
 
 :command:`add {URI}`
     Adds the file ``URI`` to the playlist
@@ -507,7 +583,7 @@ The current playlist
      OK
 
 :command:`clear`
-    Clears the current playlist.
+    Clears the queue.
 
 .. _command_delete:
 
@@ -532,13 +608,13 @@ The current playlist
 
 :command:`playlist`
 
-    Displays the current playlist.
+    Displays the queue.
 
     Do not use this, instead use :ref:`playlistinfo
     <command_playlistinfo>`.
 
 :command:`playlistfind {TAG} {NEEDLE}`
-    Finds songs in the current playlist with strict
+    Finds songs in the queue with strict
     matching.
 
 :command:`playlistid {SONGID}`
@@ -556,7 +632,7 @@ The current playlist
 
 :command:`playlistsearch {TAG} {NEEDLE}`
     Searches case-insensitively for partial matches in the
-    current playlist.
+    queue.
 
 :command:`plchanges {VERSION} [START:END]`
     Displays changed songs currently in the playlist since
@@ -593,7 +669,7 @@ The current playlist
     but address the songs with their id.
 
 :command:`rangeid {ID} {START:END}` [#since_0_19]_
-    Since ``MPD``
+    Since :program:`MPD`
     0.19 Specifies the portion of the
     song that shall be played.  ``START`` and
     ``END`` are offsets in seconds
@@ -603,7 +679,7 @@ The current playlist
     playing cannot be manipulated this way.
 
 :command:`shuffle [START:END]`
-    Shuffles the current playlist.
+    Shuffles the queue.
     ``START:END`` is optional and specifies
     a range of songs.
 
@@ -657,6 +733,8 @@ remote playlists (absolute URI with a supported scheme).
     between clients and the server, clients should not
     compare this value with their local clock.
 
+.. _command_load:
+
 :command:`load {NAME} [START:END]`
     Loads the playlist into the current queue.  Playlist
     plugins are supported.  A range may be specified to load
@@ -687,8 +765,10 @@ remote playlists (absolute URI with a supported scheme).
     Removes the playlist `NAME.m3u` from
     the playlist directory.
 
+.. _command_save:
+
 :command:`save {NAME}`
-    Saves the current playlist to
+    Saves the queue to
     `NAME.m3u` in the playlist directory.
 
 The music database
@@ -773,7 +853,7 @@ The music database
 :command:`list {TYPE} {FILTER} [group {GROUPTYPE}]`
     Lists unique tags values of the specified type.
     ``TYPE`` can be any tag supported by
-    ``MPD`` or
+    :program:`MPD` or
     *file*.
 
     Additional arguments may specify a :ref:`filter <filter_syntax>`.
@@ -792,10 +872,10 @@ The music database
     ``URI``.
 
     Do not use this command.  Do not manage a client-side
-    copy of ``MPD``'s database.  That
+    copy of :program:`MPD`'s database.  That
     is fragile and adds huge overhead.  It will break with
     large databases.  Instead, query
-    ``MPD`` whenever you need
+    :program:`MPD` whenever you need
     something.
 
 .. _command_listallinfo:
@@ -806,16 +886,16 @@ The music database
     as :ref:`lsinfo <command_lsinfo>`
 
     Do not use this command.  Do not manage a client-side
-    copy of ``MPD``'s database.  That
+    copy of :program:`MPD`'s database.  That
     is fragile and adds huge overhead.  It will break with
     large databases.  Instead, query
-    ``MPD`` whenever you need
+    :program:`MPD` whenever you need
     something.
 
 :command:`listfiles {URI}`
     Lists the contents of the directory
     ``URI``, including files are not
-    recognized by ``MPD``.
+    recognized by :program:`MPD`.
     ``URI`` can be a path relative to the
     music directory or an URI understood by one of the
     storage plugins.  The response contains at least one
@@ -922,7 +1002,7 @@ Multiple storages can be "mounted" together, similar to the
 `mount` command on many operating
 systems, but without cooperation from the kernel.  No
 superuser privileges are necessary, beause this mapping exists
-only inside the ``MPD`` process
+only inside the :program:`MPD` process
 
 .. _command_mount:
 
@@ -965,15 +1045,15 @@ Stickers
 
 "Stickers" [#since_0_15]_ are pieces of
 information attached to existing
-``MPD`` objects (e.g. song files,
+:program:`MPD` objects (e.g. song files,
 directories, albums).  Clients can create arbitrary name/value
-pairs.  ``MPD`` itself does not assume
+pairs.  :program:`MPD` itself does not assume
 any special meaning in them.
 
 The goal is to allow clients to share additional (possibly
 dynamic) information about songs, which is neither stored on
 the client (not available to other clients), nor stored in the
-song files (``MPD`` has no write
+song files (:program:`MPD` has no write
 access).
 
 Client developers should create a standard for common sticker
@@ -1015,14 +1095,21 @@ Connection settings
 ===================
 
 :command:`close`
-    Closes the connection to ``MPD``.
-    ``MPD`` will try to send the
+    Closes the connection to :program:`MPD`.
+    :program:`MPD` will try to send the
     remaining output buffer before it actually closes the
     connection, but that cannot be guaranteed.  This command
     will not generate a response.
 
+    Clients should not use this command; instead, they should just
+    close the socket.
+
 :command:`kill`
-    Kills ``MPD``.
+    Kills :program:`MPD`.
+
+    Do not use this command.  Send ``SIGTERM`` to :program:`MPD`
+    instead, or better: let your service manager handle :program:`MPD`
+    shutdown (e.g. :command:`systemctl stop mpd`).
 
 :command:`password {PASSWORD}`
     This is used for authentication with the server.
@@ -1056,7 +1143,7 @@ Connection settings
 
 :command:`tagtypes clear`
     Clear the list of tag types this client is interested
-    in.  This means that ``MPD`` will
+    in.  This means that :program:`MPD` will
     not send any tags to this client.
 
 :command:`tagtypes all`

doc/user.rst

@@ -54,7 +54,7 @@ Download the source tarball from the `MPD home page <https://musicpd.org>`_ and
 In any case, you need:
 
 * a C++14 compiler (e.g. gcc 6.0 or clang 3.9)
-* `Meson 0.47 <http://mesonbuild.com/>`__ and `Ninja
+* `Meson 0.47.2 <http://mesonbuild.com/>`__ and `Ninja
   <https://ninja-build.org/>`__
 * Boost 1.58
 * pkg-config 
@@ -67,6 +67,7 @@ For example, the following installs a fairly complete list of build dependencies
 .. code-block:: none
 
     apt install g++ \
+      libpcre3-dev \
       libmad0-dev libmpg123-dev libid3tag0-dev \
       libflac-dev libvorbis-dev libopus-dev \
       libadplug-dev libaudiofile-dev libsndfile1-dev libfaad-dev \
@@ -967,7 +968,16 @@ All :program:`MPD` crashes are bugs which must be fixed by a developer, and you
 
 A crash bug report needs to contain a "backtrace".
 
-First of all, your :program:`MPD` executable must not be "stripped" (i.e. debug information deleted). The executables shipped with Linux distributions are usually stripped, but some have so-called "debug" packages (package mpd-dbg or mpd-dbgsym on Debian, mpd-debug on other distributions). Make sure this package is installed.
+First of all, your :program:`MPD` executable must not be "stripped"
+(i.e. debug information deleted).  The executables shipped with Linux
+distributions are usually stripped, but some have so-called "debug"
+packages (package :file:`mpd-dbgsym` or :file:`mpd-dbg` on Debian,
+:file:`mpd-debug` on other distributions).  Make sure this package is
+installed.
+
+If you built :program:`MPD` from sources, please recompile with Meson
+option ":code:`--buildtype=debug -Db_ndebug=false`", because this will
+add more helpful information to the backtrace.
 
 You can extract the backtrace from a core dump, or by running :program:`MPD` in a debugger, e.g.:
 
@@ -976,4 +986,5 @@ You can extract the backtrace from a core dump, or by running :program:`MPD` in
     gdb --args mpd --stdout --no-daemon --verbose
     run
 
-As soon as you have reproduced the crash, type "bt" on the gdb command prompt. Copy the output to your bug report.
+As soon as you have reproduced the crash, type ":command:`bt`" on the
+gdb command prompt. Copy the output to your bug report.

meson.build

@@ -1,8 +1,8 @@
 project(
   'mpd',
   ['c', 'cpp'],
-  version: '0.21',
-  meson_version: '>= 0.47',
+  version: '0.21.3',
+  meson_version: '>= 0.47.2',
   default_options: [
     'c_std=c99',
     'cpp_std=c++14'
@@ -172,6 +172,11 @@ inc = include_directories(
 )
 
 boost_dep = dependency('boost', version: '>= 1.58')
+if boost_dep.version() == '1.67'
+  # https://github.com/MusicPlayerDaemon/MPD/pull/384
+  # https://github.com/boostorg/lockfree/commit/12726cda009a855073b9bedbdce57b6ce7763da2
+  warning('Your Boost version 1.67 is known to be buggy, and the MPD build will fail. Please upgrade to Boost 1.68 or later.')
+endif
 
 sources = [
   version_cxx,
@@ -310,6 +315,7 @@ subdir('src/lib/gcrypt')
 subdir('src/lib/wrap')
 subdir('src/lib/nfs')
 subdir('src/lib/oss')
+subdir('src/lib/pcre')
 subdir('src/lib/pulse')
 subdir('src/lib/sndio')
 subdir('src/lib/sqlite')

meson_options.txt

@@ -133,7 +133,7 @@ option('wavpack', type: 'feature', description: 'WavPack decoder plugin')
 option('wildmidi', type: 'feature', description: 'WildMidi decoder plugin')
 
 #
-# Decoder plugins
+# Encoder plugins
 #
 
 option('vorbisenc', type: 'feature', description: 'Vorbis encoder plugin')
@@ -176,6 +176,7 @@ option('expat', type: 'feature', description: 'Expat XML support')
 option('icu', type: 'feature', description: 'Use libicu for Unicode')
 option('iconv', type: 'feature', description: 'Use iconv() for character set conversion')
 option('libwrap', type: 'feature', description: 'libwrap support')
+option('pcre', type: 'feature', description: 'Enable regular expression support (using libpcre)')
 option('sqlite', type: 'feature', description: 'SQLite database support (for stickers)')
 option('yajl', type: 'feature', description: 'libyajl for YAML support')
 option('zlib', type: 'feature', description: 'zlib support (for database compression)')

python/build/libs.py

@@ -112,8 +112,8 @@ liblame = AutotoolsProject(
 )
 
 ffmpeg = FfmpegProject(
-    'http://ffmpeg.org/releases/ffmpeg-4.0.2.tar.xz',
-    'a95c0cc9eb990e94031d2183f2e6e444cc61c99f6f182d1575c433d62afb2f97',
+    'http://ffmpeg.org/releases/ffmpeg-4.1.tar.xz',
+    'a38ec4d026efb58506a99ad5cd23d5a9793b4bf415f2c4c2e9c1bb444acd1994',
     'lib/libavcodec.a',
     [
         '--disable-shared', '--enable-static',
@@ -341,8 +341,8 @@ ffmpeg = FfmpegProject(
 )
 
 curl = AutotoolsProject(
-    'http://curl.haxx.se/download/curl-7.61.1.tar.xz',
-    '3d5913d6a39bd22e68e34dff697fd6e4c3c81563f580c76fca2009315cd81891',
+    'http://curl.haxx.se/download/curl-7.62.0.tar.xz',
+    'dab5643a5fe775ae92570b9f3df6b0ef4bc2a827a959361fb130c73b721275c1',
     'lib/libcurl.a',
     [
         '--disable-shared', '--enable-static',

python/build/zlib.py

@@ -18,5 +18,5 @@ class ZlibProject(Project):
             'INCLUDE_PATH='+ os.path.join(toolchain.install_prefix, 'include'),
             'LIBRARY_PATH=' + os.path.join(toolchain.install_prefix, 'lib'),
             'BINARY_PATH=' + os.path.join(toolchain.install_prefix, 'bin'),
-            'SHARED_MODE=1'],
+            ],
             cwd=src, env=toolchain.env)

src/LogInit.cxx

@@ -30,6 +30,10 @@
 #include "util/RuntimeError.hxx"
 #include "system/Error.hxx"
 
+#ifdef ENABLE_SYSTEMD_DAEMON
+#include <systemd/sd-daemon.h>
+#endif
+
 #include <assert.h>
 #include <string.h>
 #include <fcntl.h>
@@ -139,6 +143,16 @@ log_init(const ConfigData &config, bool verbose, bool use_stdout)
 		if (param == nullptr) {
 			/* no configuration: default to syslog (if
 			   available) */
+#ifdef ENABLE_SYSTEMD_DAEMON
+			if (sd_booted() &&
+			    getenv("NOTIFY_SOCKET") != nullptr) {
+				/* if MPD was started as a systemd
+				   service, default to journal (which
+				   is connected to fd=2) */
+				out_fd = STDOUT_FILENO;
+				return;
+			}
+#endif
 #ifndef HAVE_SYSLOG
 			throw std::runtime_error("config parameter 'log_file' not found");
 #endif

src/check.h

@@ -37,11 +37,4 @@
 #error config.h missing
 #endif
 
-#if defined(__linux__) && !defined(NDEBUG) && defined(ENABLE_LARGEFILE) && \
-	defined(_FEATURES_H) && defined(__i386__) && \
-	!defined(__USE_FILE_OFFSET64)
-/* on i386, check if LFS is enabled */
-#error config.h was included too late
-#endif
-
 #endif

src/decoder/plugins/FfmpegDecoderPlugin.cxx

@@ -105,45 +105,11 @@ ffmpeg_finish() noexcept
 	av_dict_free(&avformat_options);
 }
 
-#if LIBAVCODEC_VERSION_INT >= AV_VERSION_INT(57, 25, 0) /* FFmpeg 3.1 */
-
-gcc_pure
-static const AVCodecParameters &
-GetCodecParameters(const AVStream &stream) noexcept
-{
-	return *stream.codecpar;
-}
-
-gcc_pure
-static AVSampleFormat
-GetSampleFormat(const AVCodecParameters &codec_params) noexcept
-{
-	return AVSampleFormat(codec_params.format);
-}
-
-#else
-
-gcc_pure
-static const AVCodecContext &
-GetCodecParameters(const AVStream &stream) noexcept
-{
-	return *stream.codec;
-}
-
-gcc_pure
-static AVSampleFormat
-GetSampleFormat(const AVCodecContext &codec_context) noexcept
-{
-	return codec_context.sample_fmt;
-}
-
-#endif
-
 gcc_pure
 static bool
 IsAudio(const AVStream &stream) noexcept
 {
-	return GetCodecParameters(stream).codec_type == AVMEDIA_TYPE_AUDIO;
+	return stream.codecpar->codec_type == AVMEDIA_TYPE_AUDIO;
 }
 
 gcc_pure
@@ -278,8 +244,6 @@ FfmpegSendFrame(DecoderClient &client, InputStream &is,
 				 codec_context.bit_rate / 1000);
 }
 
-#if LIBAVCODEC_VERSION_INT >= AV_VERSION_INT(57, 37, 0)
-
 static DecoderCommand
 FfmpegReceiveFrames(DecoderClient &client, InputStream &is,
 		    AVCodecContext &codec_context,
@@ -324,8 +288,6 @@ FfmpegReceiveFrames(DecoderClient &client, InputStream &is,
 	}
 }
 
-#endif
-
 /**
  * Decode an #AVPacket and send the resulting PCM data to the decoder
  * API.
@@ -357,7 +319,6 @@ ffmpeg_send_packet(DecoderClient &client, InputStream &is,
 								  stream.time_base));
 	}
 
-#if LIBAVCODEC_VERSION_INT >= AV_VERSION_INT(57, 37, 0)
 	bool eof = false;
 
 	int err = avcodec_send_packet(&codec_context, &packet);
@@ -386,30 +347,6 @@ ffmpeg_send_packet(DecoderClient &client, InputStream &is,
 
 	if (eof)
 		cmd = DecoderCommand::STOP;
-#else
-	DecoderCommand cmd = DecoderCommand::NONE;
-	while (packet.size > 0 && cmd == DecoderCommand::NONE) {
-		int got_frame = 0;
-		int len = avcodec_decode_audio4(&codec_context,
-						&frame, &got_frame,
-						&packet);
-		if (len < 0) {
-			/* if error, we skip the frame */
-			LogFfmpegError(len, "decoding failed, frame skipped");
-			break;
-		}
-
-		packet.data += len;
-		packet.size -= len;
-
-		if (!got_frame || frame.nb_samples <= 0)
-			continue;
-
-		cmd = FfmpegSendFrame(client, is, codec_context,
-				      frame, skip_bytes,
-				      buffer);
-	}
-#endif
 
 	return cmd;
 }
@@ -585,11 +522,7 @@ FfmpegDecode(DecoderClient &client, InputStream &input,
 
 	AVStream &av_stream = *format_context.streams[audio_stream];
 
-#if LIBAVFORMAT_VERSION_INT < AV_VERSION_INT(57, 5, 0)
-	AVCodecContext *codec_context = av_stream.codec;
-#endif
-
-	const auto &codec_params = GetCodecParameters(av_stream);
+	const auto &codec_params = *av_stream.codecpar;
 
 	const AVCodecDescriptor *codec_descriptor =
 		avcodec_descriptor_get(codec_params.codec_id);
@@ -604,7 +537,6 @@ FfmpegDecode(DecoderClient &client, InputStream &input,
 		return;
 	}
 
-#if LIBAVFORMAT_VERSION_INT >= AV_VERSION_INT(57, 5, 0)
 	AVCodecContext *codec_context = avcodec_alloc_context3(codec);
 	if (codec_context == nullptr) {
 		LogError(ffmpeg_domain, "avcodec_alloc_context3() failed");
@@ -615,26 +547,7 @@ FfmpegDecode(DecoderClient &client, InputStream &input,
 		avcodec_free_context(&codec_context);
 	};
 
-#if LIBAVCODEC_VERSION_INT >= AV_VERSION_INT(57, 25, 0) /* FFmpeg 3.1 */
 	avcodec_parameters_to_context(codec_context, av_stream.codecpar);
-#endif
-#endif
-
-	const SampleFormat sample_format =
-		ffmpeg_sample_format(GetSampleFormat(codec_params));
-	if (sample_format == SampleFormat::UNDEFINED) {
-		// (error message already done by ffmpeg_sample_format())
-		return;
-	}
-
-	const auto audio_format = CheckAudioFormat(codec_params.sample_rate,
-						   sample_format,
-						   codec_params.channels);
-
-	/* the audio format must be read from AVCodecContext by now,
-	   because avcodec_open() has been demonstrated to fill bogus
-	   values into AVCodecContext.channels - a change that will be
-	   reverted later by avcodec_decode_audio3() */
 
 	const int open_result = avcodec_open2(codec_context, codec, nullptr);
 	if (open_result < 0) {
@@ -642,11 +555,16 @@ FfmpegDecode(DecoderClient &client, InputStream &input,
 		return;
 	}
 
-#if LIBAVFORMAT_VERSION_INT < AV_VERSION_INT(57, 5, 0)
-	AtScopeExit(codec_context) {
-		avcodec_close(codec_context);
-	};
-#endif
+	const SampleFormat sample_format =
+		ffmpeg_sample_format(codec_context->sample_fmt);
+	if (sample_format == SampleFormat::UNDEFINED) {
+		// (error message already done by ffmpeg_sample_format())
+		return;
+	}
+
+	const auto audio_format = CheckAudioFormat(codec_context->sample_rate,
+						   sample_format,
+						   codec_context->channels);
 
 	const SignedSongTime total_time =
 		av_stream.duration != (int64_t)AV_NOPTS_VALUE
@@ -697,6 +615,10 @@ FfmpegDecode(DecoderClient &client, InputStream &input,
 			/* end of file */
 			break;
 
+		AtScopeExit(&packet) {
+			av_packet_unref(&packet);
+		};
+
 		FfmpegCheckTag(client, input, format_context, audio_stream);
 
 		if (packet.size > 0 && packet.stream_index == audio_stream) {
@@ -710,12 +632,6 @@ FfmpegDecode(DecoderClient &client, InputStream &input,
 			min_frame = 0;
 		} else
 			cmd = client.GetCommand();
-
-#if LIBAVCODEC_VERSION_INT >= AV_VERSION_INT(56, 25, 100)
-		av_packet_unref(&packet);
-#else
-		av_free_packet(&packet);
-#endif
 	}
 }
 
@@ -769,10 +685,10 @@ FfmpegScanStream(AVFormatContext &format_context,
 		handler.OnDuration(FromFfmpegTime(format_context.duration,
 						  AV_TIME_BASE_Q));
 
-	const auto &codec_params = GetCodecParameters(stream);
+	const auto &codec_params = *stream.codecpar;
 	try {
 		handler.OnAudioFormat(CheckAudioFormat(codec_params.sample_rate,
-						       ffmpeg_sample_format(GetSampleFormat(codec_params)),
+						       ffmpeg_sample_format(AVSampleFormat(codec_params.format)),
 						       codec_params.channels));
 	} catch (...) {
 	}

src/event/MultiSocketMonitor.hxx

@@ -194,6 +194,19 @@ public:
 	void ReplaceSocketList(pollfd *pfds, unsigned n) noexcept;
 #endif
 
+	/**
+	 * Invoke a function for each socket which has become ready.
+	 */
+	template<typename F>
+	void ForEachReturnedEvent(F &&f) noexcept {
+		for (auto &i : fds) {
+			if (i.GetReturnedEvents() != 0) {
+				f(i.GetSocket(), i.GetReturnedEvents());
+				i.ClearReturnedEvents();
+			}
+		}
+	}
+
 protected:
 	/**
 	 * Override this method and update the socket registrations.

src/event/Thread.cxx

@@ -20,6 +20,7 @@
 #include "config.h"
 #include "Thread.hxx"
 #include "thread/Name.hxx"
+#include "thread/Slack.hxx"
 #include "thread/Util.hxx"
 #include "Log.hxx"
 
@@ -46,6 +47,8 @@ EventThread::Run() noexcept
 	SetThreadName(realtime ? "rtio" : "io");
 
 	if (realtime) {
+		SetThreadTimerSlackUS(10);
+
 		try {
 			SetThreadRealtime();
 		} catch (...) {

src/input/plugins/AlsaInputPlugin.cxx

@@ -34,7 +34,6 @@
 #include "util/Domain.hxx"
 #include "util/RuntimeError.hxx"
 #include "util/StringCompare.hxx"
-#include "util/ReusableArray.hxx"
 #include "util/ASCII.hxx"
 #include "Log.hxx"
 #include "event/MultiSocketMonitor.hxx"
@@ -69,7 +68,7 @@ class AlsaInputStream final
 	snd_pcm_t *const capture_handle;
 	const size_t frame_size;
 
-	ReusableArray<pollfd> pfd_buffer;
+	AlsaNonBlockPcm non_block;
 
 	DeferEvent defer_invalidate_sockets;
 
@@ -180,12 +179,14 @@ AlsaInputStream::PrepareSockets() noexcept
 		return std::chrono::steady_clock::duration(-1);
 	}
 
-	return PrepareAlsaPcmSockets(*this, capture_handle, pfd_buffer);
+	return non_block.PrepareSockets(*this, capture_handle);
 }
 
 void
 AlsaInputStream::DispatchSockets() noexcept
 {
+	non_block.DispatchSockets(*this, capture_handle);
+
 	const std::lock_guard<Mutex> protect(mutex);
 
 	auto w = PrepareWriteBuffer();

src/lib/alsa/NonBlock.cxx

@@ -23,8 +23,7 @@
 #include "util/RuntimeError.hxx"
 
 std::chrono::steady_clock::duration
-PrepareAlsaPcmSockets(MultiSocketMonitor &m, snd_pcm_t *pcm,
-		      ReusableArray<pollfd> &pfd_buffer)
+AlsaNonBlockPcm::PrepareSockets(MultiSocketMonitor &m, snd_pcm_t *pcm)
 {
 	int count = snd_pcm_poll_descriptors_count(pcm);
 	if (count <= 0) {
@@ -50,9 +49,32 @@ PrepareAlsaPcmSockets(MultiSocketMonitor &m, snd_pcm_t *pcm,
 	return std::chrono::steady_clock::duration(-1);
 }
 
+void
+AlsaNonBlockPcm::DispatchSockets(MultiSocketMonitor &m,
+				 snd_pcm_t *pcm) noexcept
+{
+	int count = snd_pcm_poll_descriptors_count(pcm);
+	if (count <= 0)
+		return;
+
+	const auto pfds = pfd_buffer.Get(count), end = pfds + count;
+
+	auto *i = pfds;
+	m.ForEachReturnedEvent([&i, end](SocketDescriptor s, unsigned events){
+			if (i >= end)
+				return;
+
+			i->fd = s.Get();
+			i->events = i->revents = events;
+			++i;
+		});
+
+	unsigned short dummy;
+	snd_pcm_poll_descriptors_revents(pcm, pfds, i - pfds, &dummy);
+}
+
 std::chrono::steady_clock::duration
-PrepareAlsaMixerSockets(MultiSocketMonitor &m, snd_mixer_t *mixer,
-			ReusableArray<pollfd> &pfd_buffer) noexcept
+AlsaNonBlockMixer::PrepareSockets(MultiSocketMonitor &m, snd_mixer_t *mixer) noexcept
 {
 	int count = snd_mixer_poll_descriptors_count(mixer);
 	if (count <= 0) {
@@ -69,3 +91,27 @@ PrepareAlsaMixerSockets(MultiSocketMonitor &m, snd_mixer_t *mixer,
 	m.ReplaceSocketList(pfds, count);
 	return std::chrono::steady_clock::duration(-1);
 }
+
+void
+AlsaNonBlockMixer::DispatchSockets(MultiSocketMonitor &m,
+				   snd_mixer_t *mixer) noexcept
+{
+	int count = snd_mixer_poll_descriptors_count(mixer);
+	if (count <= 0)
+		return;
+
+	const auto pfds = pfd_buffer.Get(count), end = pfds + count;
+
+	auto *i = pfds;
+	m.ForEachReturnedEvent([&i, end](SocketDescriptor s, unsigned events){
+			if (i >= end)
+				return;
+
+			i->fd = s.Get();
+			i->events = i->revents = events;
+			++i;
+		});
+
+	unsigned short dummy;
+	snd_mixer_poll_descriptors_revents(mixer, pfds, i - pfds, &dummy);
+}

src/lib/alsa/NonBlock.hxx

@@ -30,23 +30,42 @@
 class MultiSocketMonitor;
 
 /**
- * Update #MultiSocketMonitor's socket list from
- * snd_pcm_poll_descriptors().  To be called from
- * MultiSocketMonitor::PrepareSockets().
- *
- * Throws exception on error.
+ * Helper class for #MultiSocketMonitor's virtual methods which
+ * manages the file descriptors for a #snd_pcm_t.
  */
-std::chrono::steady_clock::duration
-PrepareAlsaPcmSockets(MultiSocketMonitor &m, snd_pcm_t *pcm,
-		      ReusableArray<pollfd> &pfd_buffer);
+class AlsaNonBlockPcm {
+	ReusableArray<pollfd> pfd_buffer;
+
+public:
+	/**
+	 * Throws on error.
+	 */
+	std::chrono::steady_clock::duration PrepareSockets(MultiSocketMonitor &m,
+							   snd_pcm_t *pcm);
+
+	/**
+	 * Wrapper for snd_pcm_poll_descriptors_revents(), to be
+	 * called from MultiSocketMonitor::DispatchSockets().
+	 */
+	void DispatchSockets(MultiSocketMonitor &m, snd_pcm_t *pcm) noexcept;
+};
 
 /**
- * Update #MultiSocketMonitor's socket list from
- * snd_mixer_poll_descriptors().  To be called from
- * MultiSocketMonitor::PrepareSockets().
+ * Helper class for #MultiSocketMonitor's virtual methods which
+ * manages the file descriptors for a #snd_mixer_t.
  */
-std::chrono::steady_clock::duration
-PrepareAlsaMixerSockets(MultiSocketMonitor &m, snd_mixer_t *mixer,
-		      ReusableArray<pollfd> &pfd_buffer) noexcept;
+class AlsaNonBlockMixer {
+	ReusableArray<pollfd> pfd_buffer;
+
+public:
+	std::chrono::steady_clock::duration PrepareSockets(MultiSocketMonitor &m,
+							   snd_mixer_t *mixer) noexcept;
+
+	/**
+	 * Wrapper for snd_mixer_poll_descriptors_revents(), to be
+	 * called from MultiSocketMonitor::DispatchSockets().
+	 */
+	void DispatchSockets(MultiSocketMonitor &m, snd_mixer_t *mixer) noexcept;
+};
 
 #endif

src/lib/ffmpeg/meson.build

@@ -1,6 +1,6 @@
-libavformat_dep = dependency('libavformat', version: '>= 56.1', required: get_option('ffmpeg'))
-libavcodec_dep = dependency('libavcodec', version: '>= 56.1', required: get_option('ffmpeg'))
-libavutil_dep = dependency('libavutil', version: '>= 54.3', required: get_option('ffmpeg'))
+libavformat_dep = dependency('libavformat', version: '>= 57.40', required: get_option('ffmpeg'))
+libavcodec_dep = dependency('libavcodec', version: '>= 57.48', required: get_option('ffmpeg'))
+libavutil_dep = dependency('libavutil', version: '>= 55.27', required: get_option('ffmpeg'))
 
 enable_ffmpeg = libavformat_dep.found() and libavcodec_dep.found() and libavutil_dep.found()
 conf.set('ENABLE_FFMPEG', enable_ffmpeg)
@@ -26,4 +26,9 @@ ffmpeg = static_library(
 
 ffmpeg_dep = declare_dependency(
   link_with: ffmpeg,
+  dependencies: [
+    libavformat_dep,
+    libavcodec_dep,
+    libavutil_dep,
+  ],
 )

src/lib/pcre/RegexPointer.hxx

@@ -0,0 +1,66 @@
+/*
+ * Copyright 2007-2018 Content Management AG
+ * All rights reserved.
+ *
+ * author: Max Kellermann <mk@cm4all.com>
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *
+ * - Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ *
+ * - Redistributions in binary form must reproduce the above copyright
+ * notice, this list of conditions and the following disclaimer in the
+ * documentation and/or other materials provided with the
+ * distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
+ * FOR A PARTICULAR PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE
+ * FOUNDATION OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
+ * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
+ * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
+ * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
+ * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+ * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
+ * OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#ifndef REGEX_POINTER_HXX
+#define REGEX_POINTER_HXX
+
+#include "util/StringView.hxx"
+#include "util/Compiler.h"
+
+#include <pcre.h>
+
+#include <array>
+
+class RegexPointer {
+protected:
+	pcre *re = nullptr;
+	pcre_extra *extra = nullptr;
+
+	unsigned n_capture = 0;
+
+public:
+	constexpr bool IsDefined() const noexcept {
+		return re != nullptr;
+	}
+
+	gcc_pure
+	bool Match(StringView s) const noexcept {
+		/* we don't need the data written to ovector, but PCRE can
+		   omit internal allocations if we pass a buffer to
+		   pcre_exec() */
+		std::array<int, 16> ovector;
+		return pcre_exec(re, extra, s.data, s.size,
+				 0, 0, &ovector.front(), ovector.size()) >= 0;
+	}
+};
+
+#endif

src/lib/pcre/UniqueRegex.cxx

@@ -0,0 +1,71 @@
+/*
+ * Copyright 2007-2018 Content Management AG
+ * All rights reserved.
+ *
+ * author: Max Kellermann <mk@cm4all.com>
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *
+ * - Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ *
+ * - Redistributions in binary form must reproduce the above copyright
+ * notice, this list of conditions and the following disclaimer in the
+ * documentation and/or other materials provided with the
+ * distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
+ * FOR A PARTICULAR PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE
+ * FOUNDATION OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
+ * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
+ * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
+ * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
+ * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+ * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
+ * OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#include "UniqueRegex.hxx"
+#include "util/RuntimeError.hxx"
+
+void
+UniqueRegex::Compile(const char *pattern, bool anchored, bool capture,
+		     bool caseless)
+{
+	constexpr int default_options = PCRE_DOTALL|PCRE_NO_AUTO_CAPTURE|PCRE_UTF8;
+
+	int options = default_options;
+	if (anchored)
+		options |= PCRE_ANCHORED;
+	if (capture)
+		options &= ~PCRE_NO_AUTO_CAPTURE;
+	if (caseless)
+		options |= PCRE_CASELESS;
+
+	const char *error_string;
+	int error_offset;
+	re = pcre_compile(pattern, options, &error_string, &error_offset, nullptr);
+	if (re == nullptr)
+		throw FormatRuntimeError("Error in regex at offset %d: %s",
+					 error_offset, error_string);
+
+	int study_options = 0;
+#ifdef PCRE_CONFIG_JIT
+	study_options |= PCRE_STUDY_JIT_COMPILE;
+#endif
+	extra = pcre_study(re, study_options, &error_string);
+	if (extra == nullptr && error_string != nullptr) {
+		pcre_free(re);
+		re = nullptr;
+		throw FormatRuntimeError("Regex study error: %s", error_string);
+	}
+
+	int n;
+	if (capture && pcre_fullinfo(re, extra, PCRE_INFO_CAPTURECOUNT, &n) == 0)
+		n_capture = n;
+}

src/lib/pcre/UniqueRegex.hxx

@@ -0,0 +1,79 @@
+/*
+ * Copyright 2007-2018 Content Management AG
+ * All rights reserved.
+ *
+ * author: Max Kellermann <mk@cm4all.com>
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *
+ * - Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ *
+ * - Redistributions in binary form must reproduce the above copyright
+ * notice, this list of conditions and the following disclaimer in the
+ * documentation and/or other materials provided with the
+ * distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
+ * FOR A PARTICULAR PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE
+ * FOUNDATION OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
+ * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
+ * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
+ * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
+ * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+ * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
+ * OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#ifndef UNIQUE_REGEX_HXX
+#define UNIQUE_REGEX_HXX
+
+#include "RegexPointer.hxx"
+#include "util/StringView.hxx"
+
+#include <algorithm>
+
+#include <pcre.h>
+
+class UniqueRegex : public RegexPointer {
+public:
+	UniqueRegex() = default;
+
+	UniqueRegex(const char *pattern, bool anchored, bool capture,
+		    bool caseless) {
+		Compile(pattern, anchored, capture, caseless);
+	}
+
+	UniqueRegex(UniqueRegex &&src) noexcept:RegexPointer(src) {
+		src.re = nullptr;
+		src.extra = nullptr;
+	}
+
+	~UniqueRegex() noexcept {
+		pcre_free(re);
+#ifdef PCRE_CONFIG_JIT
+		pcre_free_study(extra);
+#else
+		pcre_free(extra);
+#endif
+	}
+
+	UniqueRegex &operator=(UniqueRegex &&src) {
+		using std::swap;
+		swap<RegexPointer>(*this, src);
+		return *this;
+	}
+
+	/**
+	 * Throws std::runtime_error on error.
+	 */
+	void Compile(const char *pattern, bool anchored, bool capture,
+		     bool caseless);
+};
+
+#endif

src/lib/pcre/meson.build

@@ -0,0 +1,21 @@
+pcre_dep = dependency('libpcre', required: get_option('pcre'))
+conf.set('HAVE_PCRE', pcre_dep.found())
+if not pcre_dep.found()
+  subdir_done()
+endif
+
+pcre = static_library(
+  'pcre',
+  'UniqueRegex.cxx',
+  include_directories: inc,
+  dependencies: [
+    pcre_dep,
+  ],
+)
+
+pcre_dep = declare_dependency(
+  link_with: pcre,
+  dependencies: [
+    pcre_dep,
+  ],
+)

src/lib/xiph/meson.build

@@ -2,10 +2,15 @@ libflac_dep = dependency('flac', version: '>= 1.2', required: get_option('flac')
 libopus_dep = dependency('opus', required: get_option('opus'))
 libvorbis_dep = dependency('vorbis', required: get_option('vorbis'))
 
-if need_encoder
-  libvorbisenc_dep = dependency('vorbisenc', required: get_option('vorbisenc'))
-else
-  libvorbisenc_dep = dependency('', required: false)
+libvorbisenc_dep = dependency('', required: false)
+if need_encoder and not get_option('vorbisenc').disabled()
+  if libvorbis_dep.found()
+    libvorbisenc_dep = dependency('vorbisenc', required: get_option('vorbisenc'))
+  elif get_option('vorbisenc').enabled()
+    error('Cannot build the Vorbis encoder without the Vorbis decoder')
+  else
+    message('Disabling the Vorbis encoder because the Vorbis decoder is disabled as well')
+  endif
 endif
 
 if libopus_dep.found() or libvorbis_dep.found() or libvorbisenc_dep.found()
@@ -14,7 +19,7 @@ else
   libogg_dep = dependency('', required: false)
 endif
 
-if not libogg_dep.found() or not libflac_dep.found()
+if not libogg_dep.found() and not libflac_dep.found()
   xiph_dep = dependency('', required: false)
   ogg_dep = dependency('', required: false)
   flac_dep = dependency('', required: false)

src/lib/zlib/meson.build

@@ -1,4 +1,5 @@
 zlib_dep = dependency('zlib', required: get_option('zlib'))
+conf.set('ENABLE_ZLIB', zlib_dep.found())
 if not zlib_dep.found()
   subdir_done()
 endif
@@ -14,4 +15,7 @@ zlib = static_library(
 
 zlib_dep = declare_dependency(
   link_with: zlib,
+  dependencies: [
+    zlib_dep,
+  ],
 )

src/mixer/plugins/AlsaMixerPlugin.cxx

@@ -26,7 +26,6 @@
 #include "event/DeferEvent.hxx"
 #include "event/Call.hxx"
 #include "util/ASCII.hxx"
-#include "util/ReusableArray.hxx"
 #include "util/Domain.hxx"
 #include "util/RuntimeError.hxx"
 #include "Log.hxx"
@@ -48,7 +47,7 @@ class AlsaMixerMonitor final : MultiSocketMonitor {
 
 	snd_mixer_t *mixer;
 
-	ReusableArray<pollfd> pfd_buffer;
+	AlsaNonBlockMixer non_block;
 
 public:
 	AlsaMixerMonitor(EventLoop &_loop, snd_mixer_t *_mixer)
@@ -110,7 +109,7 @@ AlsaMixerMonitor::PrepareSockets() noexcept
 		return std::chrono::steady_clock::duration(-1);
 	}
 
-	return PrepareAlsaMixerSockets(*this, mixer, pfd_buffer);
+	return non_block.PrepareSockets(*this, mixer);
 }
 
 void
@@ -118,6 +117,8 @@ AlsaMixerMonitor::DispatchSockets() noexcept
 {
 	assert(mixer != nullptr);
 
+	non_block.DispatchSockets(*this, mixer);
+
 	int err = snd_mixer_handle_events(mixer);
 	if (err < 0) {
 		FormatError(alsa_mixer_domain,

src/mixer/plugins/volume_mapping.c

@@ -135,6 +135,13 @@ static int set_normalized_volume(snd_mixer_elem_t *elem,
 		if (err < 0)
 			return err;
 
+		/* two special cases to avoid rounding errors at 0% and
+		   100% */
+		if (volume <= 0)
+			return set_raw[ctl_dir](elem, min);
+		else if (volume >= 1)
+			return set_raw[ctl_dir](elem, max);
+
 		value = lrint_dir(volume * (max - min), dir) + min;
 		return set_raw[ctl_dir](elem, value);
 	}
@@ -143,7 +150,7 @@ static int set_normalized_volume(snd_mixer_elem_t *elem,
 	   100% */
 	if (volume <= 0)
 		return set_dB[ctl_dir](elem, min, dir);
-	else if (volume >= 100)
+	else if (volume >= 1)
 		return set_dB[ctl_dir](elem, max, dir);
 
 	if (use_linear_dB_scale(min, max)) {

src/net/IPv4Address.hxx

@@ -53,20 +53,6 @@ class IPv4Address {
 							uint8_t c, uint8_t d) noexcept {
 		return {{{ a, b, c, d }}};
 	}
-
-	/**
-	 * @param x the 32 bit IP address in network byte order
-	 */
-	static constexpr struct in_addr ConstructInAddrBE(uint32_t x) noexcept {
-		return (struct in_addr){{.S_addr=x}};
-	}
-
-	/**
-	 * @param x the 32 bit IP address in host byte order
-	 */
-	static constexpr struct in_addr ConstructInAddr(uint32_t x) noexcept {
-		return ConstructInAddr(x >> 24, x >> 16, x >> 8, x);
-	}
 #else
 
 #ifdef __BIONIC__
@@ -78,11 +64,19 @@ class IPv4Address {
 		return ToBE32((a << 24) | (b << 16) | (c << 8) | d);
 	}
 
+	static constexpr struct in_addr ConstructInAddr(uint8_t a, uint8_t b,
+							uint8_t c, uint8_t d) noexcept {
+		return { ConstructInAddrT(a, b, c, d) };
+	}
+#endif
+
 	/**
 	 * @param x the 32 bit IP address in network byte order
 	 */
 	static constexpr struct in_addr ConstructInAddrBE(uint32_t x) noexcept {
-		return { x };
+		struct in_addr ia{};
+		ia.s_addr = x;
+		return ia;
 	}
 
 	/**
@@ -92,26 +86,16 @@ class IPv4Address {
 		return ConstructInAddrBE(ToBE32(x));
 	}
 
-	static constexpr struct in_addr ConstructInAddr(uint8_t a, uint8_t b,
-							uint8_t c, uint8_t d) noexcept {
-		return { ConstructInAddrT(a, b, c, d) };
-	}
-#endif
-
 	/**
 	 * @param port the port number in host byte order
 	 */
 	static constexpr struct sockaddr_in Construct(struct in_addr address,
 						      uint16_t port) noexcept {
-		return {
-#ifdef HAVE_STRUCT_SOCKADDR_IN_SIN_LEN
-			sizeof(struct sockaddr_in),
-#endif
-			AF_INET,
-			ToBE16(port),
-			address,
-			{},
-		};
+		struct sockaddr_in sin{};
+		sin.sin_family = AF_INET;
+		sin.sin_port = ToBE16(port);
+		sin.sin_addr = address;
+		return sin;
 	}
 
 	/**

src/net/IPv6Address.hxx

@@ -68,16 +68,12 @@ class IPv6Address {
 	static constexpr struct sockaddr_in6 Construct(struct in6_addr address,
 						       uint16_t port,
 						       uint32_t scope_id) noexcept {
-		return {
-#if defined(__APPLE__)
-			sizeof(struct sockaddr_in6),
-#endif
-			AF_INET6,
-			ToBE16(port),
-			0,
-			address,
-			scope_id,
-		};
+		struct sockaddr_in6 sin{};
+		sin.sin6_family = AF_INET6;
+		sin.sin6_port = ToBE16(port);
+		sin.sin6_addr = address;
+		sin.sin6_scope_id = scope_id;
+		return sin;
 	}
 
 public:

src/net/meson.build

@@ -10,14 +10,6 @@ if have_tcp and not get_option('ipv6').disabled()
   if not have_ipv6 and get_option('ipv6').enabled()
     error('IPv6 not supported by OS')
   endif
-
-  conf.set('HAVE_STRUCT_SOCKADDR_IN_SIN_LEN', c_compiler.has_member('struct sockaddr_in', 'sin_len', prefix: '''
-#ifdef _WIN32
-#include <winsock2.h>
-#include <ws2tcpip.h>
-#else
-#include <netinet/in.h>
-#endif'''))
 else
   have_ipv6 = false
 endif

src/output/Control.cxx

@@ -347,10 +347,22 @@ AudioOutputControl::LockAllowPlay() noexcept
 void
 AudioOutputControl::LockRelease() noexcept
 {
-	if (always_on)
-		LockPauseAsync();
+	if (output->mixer != nullptr &&
+	    (!always_on || !output->SupportsPause()))
+		/* the device has no pause mode: close the mixer,
+		   unless its "global" flag is set (checked by
+		   mixer_auto_close()) */
+		mixer_auto_close(output->mixer);
+
+	const std::lock_guard<Mutex> protect(mutex);
+
+	assert(!open || !fail_timer.IsDefined());
+	assert(allow_play);
+
+	if (IsOpen())
+		CommandWait(Command::RELEASE);
 	else
-		LockCloseWait();
+		fail_timer.Reset();
 }
 
 void

src/output/Control.hxx

@@ -131,6 +131,12 @@ class AudioOutputControl {
 		CLOSE,
 		PAUSE,
 
+		/**
+		 * Close or pause the device, depending on the
+		 * #always_on setting.
+		 */
+		RELEASE,
+
 		/**
 		 * Drains the internal (hardware) buffers of the device.  This
 		 * operation may take a while to complete.

src/output/Filtered.cxx

@@ -124,9 +124,14 @@ FilteredAudioOutput::OpenOutputAndConvert(AudioFormat desired_audio_format)
 void
 FilteredAudioOutput::CloseOutput(bool drain) noexcept
 {
-	if (drain)
-		Drain();
-	else
+	if (drain) {
+		try {
+			Drain();
+		} catch (...) {
+			FormatError(std::current_exception(),
+				    "Failed to drain %s", GetLogName());
+		}
+	} else
 		Cancel();
 
 	output->Close();

src/output/Interface.hxx

@@ -159,6 +159,8 @@ public:
 
 	/**
 	 * Wait until the device has finished playing.
+	 *
+	 * Throws on error.
 	 */
 	virtual void Drain() {}
 

src/output/Source.cxx

@@ -41,8 +41,10 @@ AudioOutputSource::Open(const AudioFormat audio_format, const MusicPipe &_pipe,
 {
 	assert(audio_format.IsValid());
 
-	if (!IsOpen() || &_pipe != &pipe.GetPipe())
+	if (!IsOpen() || &_pipe != &pipe.GetPipe()) {
+		current_chunk = nullptr;
 		pipe.Init(_pipe);
+	}
 
 	/* (re)open the filter */
 

src/output/Thread.cxx

@@ -443,8 +443,7 @@ AudioOutputControl::Task() noexcept
 		case Command::PAUSE:
 			if (!open) {
 				/* the output has failed after
-				   audio_output_all_pause() has
-				   submitted the PAUSE command; bail
+				   the PAUSE command was submitted; bail
 				   out */
 				CommandFinished();
 				break;
@@ -457,6 +456,35 @@ AudioOutputControl::Task() noexcept
 			   the new command first */
 			continue;
 
+		case Command::RELEASE:
+			if (!open) {
+				/* the output has failed after
+				   the PAUSE command was submitted; bail
+				   out */
+				CommandFinished();
+				break;
+			}
+
+			if (always_on) {
+				/* in "always_on" mode, the output is
+				   paused instead of being closed;
+				   however we need to flush the
+				   AudioOutputSource because its data
+				   have been invalidated by stopping
+				   the actual playback */
+				source.Cancel();
+				InternalPause();
+			} else {
+				InternalClose(false);
+				CommandFinished();
+			}
+
+			/* don't "break" here: this might cause
+			   Play() to be called when command==CLOSE
+			   ends the paused state - "continue" checks
+			   the new command first */
+			continue;
+
 		case Command::DRAIN:
 			if (open)
 				InternalDrain();

src/output/plugins/AlsaOutputPlugin.cxx

@@ -33,6 +33,7 @@
 #include "util/RuntimeError.hxx"
 #include "util/Domain.hxx"
 #include "util/ConstBuffer.hxx"
+#include "util/ScopeExit.hxx"
 #include "util/StringView.hxx"
 #include "event/MultiSocketMonitor.hxx"
 #include "event/DeferEvent.hxx"
@@ -108,6 +109,13 @@ class AlsaOutput final
 	 */
 	snd_pcm_uframes_t period_frames;
 
+	/**
+	 * If snd_pcm_avail() goes above this value and no more data
+	 * is available in the #ring_buffer, we need to play some
+	 * silence.
+	 */
+	snd_pcm_sframes_t max_avail_frames;
+
 	/**
 	 * Is this a buggy alsa-lib version, which needs a workaround
 	 * for the snd_pcm_drain() bug always returning -EAGAIN?  See
@@ -139,6 +147,16 @@ class AlsaOutput final
 	 */
 	bool must_prepare;
 
+	/**
+	 * Has snd_pcm_writei() been called successfully at least once
+	 * since the PCM was prepared?
+	 *
+	 * This is necessary to work around a kernel bug which causes
+	 * snd_pcm_drain() to return -EAGAIN forever in non-blocking
+	 * mode if snd_pcm_writei() was never called.
+	 */
+	bool written;
+
 	bool drain;
 
 	/**
@@ -148,10 +166,7 @@ class AlsaOutput final
 	 */
 	uint8_t *silence;
 
-	/**
-	 * For PrepareAlsaPcmSockets().
-	 */
-	ReusableArray<pollfd> pfd_buffer;
+	AlsaNonBlockPcm non_block;
 
 	/**
 	 * For copying data from OutputThread to IOThread.
@@ -260,10 +275,12 @@ private:
 	/**
 	 * Drain all buffers.  To be run in #EventLoop's thread.
 	 *
+	 * Throws on error.
+	 *
 	 * @return true if draining is complete, false if this method
 	 * needs to be called again later
 	 */
-	bool DrainInternal() noexcept;
+	bool DrainInternal();
 
 	/**
 	 * Stop playback immediately, dropping all buffers.  To be run
@@ -298,14 +315,18 @@ private:
 
 		auto frames_written = snd_pcm_writei(pcm, period_buffer.GetHead(),
 						     period_buffer.GetFrames(out_frame_size));
-		if (frames_written > 0)
+		if (frames_written > 0) {
+			written = true;
 			period_buffer.ConsumeFrames(frames_written,
 						    out_frame_size);
+		}
 
 		return frames_written;
 	}
 
 	void LockCaughtError() noexcept {
+		period_buffer.Clear();
+
 		const std::lock_guard<Mutex> lock(mutex);
 		error = std::current_exception();
 		active = false;
@@ -480,6 +501,10 @@ AlsaOutput::Setup(AudioFormat &audio_format,
 
 	period_frames = alsa_period_size;
 
+	/* generate silence if there's less than once period of data
+	   in the ALSA-PCM buffer */
+	max_avail_frames = hw_result.buffer_size - hw_result.period_size;
+
 	silence = new uint8_t[snd_pcm_frames_to_bytes(pcm, alsa_period_size)];
 	snd_pcm_format_set_silence(hw_result.format, silence,
 				   alsa_period_size * audio_format.channels);
@@ -660,6 +685,8 @@ AlsaOutput::Open(AudioFormat &audio_format)
 
 	active = false;
 	must_prepare = false;
+	written = false;
+	error = {};
 }
 
 inline int
@@ -691,6 +718,7 @@ AlsaOutput::Recover(int err) noexcept
 	case SND_PCM_STATE_SETUP:
 	case SND_PCM_STATE_XRUN:
 		period_buffer.Rewind();
+		written = false;
 		err = snd_pcm_prepare(pcm);
 		break;
 	case SND_PCM_STATE_DISCONNECTED:
@@ -713,13 +741,8 @@ AlsaOutput::Recover(int err) noexcept
 }
 
 inline bool
-AlsaOutput::DrainInternal() noexcept
+AlsaOutput::DrainInternal()
 {
-	if (snd_pcm_state(pcm) != SND_PCM_STATE_RUNNING) {
-		CancelInternal();
-		return true;
-	}
-
 	/* drain ring_buffer */
 	CopyRingToPeriodBuffer();
 
@@ -732,28 +755,42 @@ AlsaOutput::DrainInternal() noexcept
 	/* drain period_buffer */
 	if (!period_buffer.IsEmpty()) {
 		auto frames_written = WriteFromPeriodBuffer();
-		if (frames_written < 0 && errno != EAGAIN) {
-			CancelInternal();
-			return true;
+		if (frames_written < 0) {
+			if (frames_written == -EAGAIN)
+				return false;
+
+			throw FormatRuntimeError("snd_pcm_writei() failed: %s",
+						 snd_strerror(-frames_written));
 		}
 
-		if (!period_buffer.IsEmpty())
-			/* need to call WriteFromPeriodBuffer() again
-			   in the next iteration, so don't finish the
-			   drain just yet */
-			return false;
+		/* need to call CopyRingToPeriodBuffer() and
+		   WriteFromPeriodBuffer() again in the next
+		   iteration, so don't finish the drain just yet */
+		return period_buffer.IsEmpty();
 	}
 
+	if (!written)
+		/* if nothing has ever been written to the PCM, we
+		   don't need to drain it */
+		return true;
+
 	/* .. and finally drain the ALSA hardware buffer */
 
+	int result;
 	if (work_around_drain_bug) {
 		snd_pcm_nonblock(pcm, 0);
-		bool result = snd_pcm_drain(pcm) != -EAGAIN;
+		result = snd_pcm_drain(pcm);
 		snd_pcm_nonblock(pcm, 1);
-		return result;
-	}
+	} else
+		result = snd_pcm_drain(pcm);
 
-	return snd_pcm_drain(pcm) != -EAGAIN;
+	if (result == 0)
+		return true;
+	else if (result == -EAGAIN)
+		return false;
+	else
+		throw FormatRuntimeError("snd_pcm_drain() failed: %s",
+					 snd_strerror(-result));
 }
 
 void
@@ -778,6 +815,9 @@ AlsaOutput::Drain()
 inline void
 AlsaOutput::CancelInternal() noexcept
 {
+	/* this method doesn't need to lock the mutex because while it
+	   runs, the calling thread is blocked inside Cancel() */
+
 	must_prepare = true;
 
 	snd_pcm_drop(pcm);
@@ -786,10 +826,7 @@ AlsaOutput::CancelInternal() noexcept
 	period_buffer.Clear();
 	ring_buffer->reset();
 
-	{
-		const std::lock_guard<Mutex> lock(mutex);
-		active = false;
-	}
+	active = false;
 
 	MultiSocketMonitor::Reset();
 	defer_invalidate_sockets.Cancel();
@@ -881,7 +918,7 @@ AlsaOutput::PrepareSockets() noexcept
 	}
 
 	try {
-		return PrepareAlsaPcmSockets(*this, pcm, pfd_buffer);
+		return non_block.PrepareSockets(*this, pcm);
 	} catch (...) {
 		ClearSocketList();
 		LockCaughtError();
@@ -892,6 +929,18 @@ AlsaOutput::PrepareSockets() noexcept
 void
 AlsaOutput::DispatchSockets() noexcept
 try {
+	non_block.DispatchSockets(*this, pcm);
+
+	if (must_prepare) {
+		must_prepare = false;
+		written = false;
+
+		int err = snd_pcm_prepare(pcm);
+		if (err < 0)
+			throw FormatRuntimeError("snd_pcm_prepare() failed: %s",
+						 snd_strerror(-err));
+	}
+
 	{
 		const std::lock_guard<Mutex> lock(mutex);
 
@@ -912,19 +961,11 @@ try {
 		}
 	}
 
-	if (must_prepare) {
-		must_prepare = false;
-
-		int err = snd_pcm_prepare(pcm);
-		if (err < 0)
-			throw FormatRuntimeError("snd_pcm_prepare() failed: %s",
-						 snd_strerror(-err));
-	}
-
 	CopyRingToPeriodBuffer();
 
 	if (period_buffer.IsEmpty()) {
-		if (snd_pcm_state(pcm) == SND_PCM_STATE_PREPARED) {
+		if (snd_pcm_state(pcm) == SND_PCM_STATE_PREPARED ||
+		    snd_pcm_avail(pcm) <= max_avail_frames) {
 			/* at SND_PCM_STATE_PREPARED (not yet switched
 			   to SND_PCM_STATE_RUNNING), we have no
 			   pressure to fill the ALSA buffer, because
@@ -934,10 +975,16 @@ try {
 			   monitoring the ALSA file descriptor, and
 			   let it be reactivated by Play()/Activate()
 			   whenever more data arrives */
+			/* the same applies when there is still enough
+			   data in the ALSA-PCM buffer (determined by
+			   snd_pcm_avail()); this can happend at the
+			   start of playback, when our ring_buffer is
+			   smaller than the ALSA-PCM buffer */
 
 			{
 				const std::lock_guard<Mutex> lock(mutex);
 				active = false;
+				cond.signal();
 			}
 
 			/* avoid race condition: see if data has

src/output/plugins/httpd/HttpdClient.hxx

@@ -98,8 +98,11 @@ class HttpdClient final
 
 	/**
 	 * If the current metadata was already sent to the client.
+	 *
+	 * Initialized to `true` because there is no metadata #Page
+	 * pending to be sent.
 	 */
-	bool metadata_sent = false;
+	bool metadata_sent = true;
 
 	/**
 	 * The amount of streaming data between each metadata block

src/player/Thread.cxx

@@ -23,7 +23,8 @@
  * between the decoder thread and the output thread(s): it receives
  * #MusicChunk objects from the decoder, optionally mixes them
  * (cross-fading), applies software volume, and sends them to the
- * audio outputs via audio_output_all_play().
+ * audio outputs via PlayerOutputs::Play()
+ * (i.e. MultipleOutputs::Play()).
  *
  * It is controlled by the main thread (the playlist code), see
  * Control.hxx.  The playlist enqueues new songs into the player
@@ -970,6 +971,15 @@ Player::Run() noexcept
 	pc.CommandFinished();
 
 	while (ProcessCommand()) {
+		if (decoder_starting) {
+			/* wait until the decoder is initialized completely */
+
+			if (!CheckDecoderStartup())
+				break;
+
+			continue;
+		}
+
 		if (buffering) {
 			/* buffering at the start of the song - wait
 			   until the buffer is large enough, to
@@ -987,15 +997,6 @@ Player::Run() noexcept
 			}
 		}
 
-		if (decoder_starting) {
-			/* wait until the decoder is initialized completely */
-
-			if (!CheckDecoderStartup())
-				break;
-
-			continue;
-		}
-
 		if (dc.IsIdle() && queued && dc.pipe == pipe) {
 			/* the decoder has finished the current song;
 			   make it decode the next song */

src/song/BaseSongFilter.cxx

@@ -19,13 +19,14 @@
 
 #include "config.h"
 #include "BaseSongFilter.hxx"
+#include "Escape.hxx"
 #include "LightSong.hxx"
 #include "util/UriUtil.hxx"
 
 std::string
 BaseSongFilter::ToExpression() const noexcept
 {
-	return "(base \"" + value + "\")";
+	return "(base \"" + EscapeFilterString(value) + "\")";
 }
 
 bool

src/song/Escape.cxx

@@ -0,0 +1,41 @@
+/*
+ * Copyright 2003-2018 The Music Player Daemon Project
+ * http://www.musicpd.org
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License along
+ * with this program; if not, write to the Free Software Foundation, Inc.,
+ * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+ */
+
+#include "Escape.hxx"
+
+static constexpr bool
+MustEscape(char ch) noexcept
+{
+	return ch == '"' || ch == '\'' || ch == '\\';
+}
+
+std::string
+EscapeFilterString(const std::string &src) noexcept
+{
+	std::string result;
+	result.reserve(src.length() + 16);
+
+	for (char ch : src) {
+		if (MustEscape(ch))
+			result.push_back('\\');
+		result.push_back(ch);
+	}
+
+	return result;
+}

src/song/Escape.hxx

@@ -0,0 +1,31 @@
+/*
+ * Copyright 2003-2018 The Music Player Daemon Project
+ * http://www.musicpd.org
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License along
+ * with this program; if not, write to the Free Software Foundation, Inc.,
+ * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+ */
+
+#ifndef MPD_SONG_ESCAPE_HXX
+#define MPD_SONG_ESCAPE_HXX
+
+#include "util/Compiler.h"
+
+#include <string>
+
+gcc_pure
+std::string
+EscapeFilterString(const std::string &src) noexcept;
+
+#endif

src/song/Filter.cxx

@@ -91,8 +91,10 @@ locate_parse_type(const char *str) noexcept
 
 SongFilter::SongFilter(TagType tag, const char *value, bool fold_case)
 {
-	and_filter.AddItem(std::make_unique<TagSongFilter>(tag, value,
-							   fold_case, false));
+	/* for compatibility with MPD 0.20 and older, "fold_case" also
+	   switches on "substring" */
+	and_filter.AddItem(std::make_unique<TagSongFilter>(tag,
+							   StringFilter(value, fold_case, fold_case, false)));
 }
 
 SongFilter::~SongFilter()
@@ -173,13 +175,76 @@ ExpectQuoted(const char *&s)
 	if (!IsQuote(quote))
 		throw std::runtime_error("Quoted string expected");
 
-	const char *begin = s;
-	const char *end = strchr(s, quote);
-	if (end == nullptr)
-		throw std::runtime_error("Closing quote not found");
+	char buffer[4096];
+	size_t length = 0;
 
-	s = StripLeft(end + 1);
-	return {begin, end};
+	while (*s != quote) {
+		if (*s == '\\')
+			/* backslash escapes the following character */
+			++s;
+
+		if (*s == 0)
+			throw std::runtime_error("Closing quote not found");
+
+		buffer[length++] = *s++;
+
+		if (length >= sizeof(buffer))
+			throw std::runtime_error("Quoted value is too long");
+	}
+
+	s = StripLeft(s + 1);
+
+	return {buffer, length};
+}
+
+/**
+ * Parse a string operator and its second operand and convert it to a
+ * #StringFilter.
+ *
+ * Throws on error.
+ */
+static StringFilter
+ParseStringFilter(const char *&s, bool fold_case)
+{
+	if (auto after_contains = StringAfterPrefixIgnoreCase(s, "contains ")) {
+		s = StripLeft(after_contains);
+		auto value = ExpectQuoted(s);
+		return StringFilter(std::move(value),
+				    fold_case, true, false);
+	}
+
+	if (auto after_not_contains = StringAfterPrefixIgnoreCase(s, "!contains ")) {
+		s = StripLeft(after_not_contains);
+		auto value = ExpectQuoted(s);
+		return StringFilter(std::move(value),
+				    fold_case, true, true);
+	}
+
+	bool negated = false;
+
+#ifdef HAVE_PCRE
+	if ((s[0] == '!' || s[0] == '=') && s[1] == '~') {
+		negated = s[0] == '!';
+		s = StripLeft(s + 2);
+		auto value = ExpectQuoted(s);
+		StringFilter f(std::move(value), fold_case, false, negated);
+		f.SetRegex(std::make_shared<UniqueRegex>(f.GetValue().c_str(),
+							 false, false,
+							 fold_case));
+		return f;
+	}
+#endif
+
+	if (s[0] == '!' && s[1] == '=')
+		negated = true;
+	else if (s[0] != '=' || s[1] != '=')
+		throw std::runtime_error("'==' or '!=' expected");
+
+	s = StripLeft(s + 2);
+	auto value = ExpectQuoted(s);
+
+	return StringFilter(std::move(value),
+			    fold_case, false, negated);
 }
 
 ISongFilterPtr
@@ -264,14 +329,7 @@ SongFilter::ParseExpression(const char *&s, bool fold_case)
 
 		return std::make_unique<AudioFormatSongFilter>(value);
 	} else {
-		bool negated = false;
-		if (s[0] == '!' && s[1] == '=')
-			negated = true;
-		else if (s[0] != '=' || s[1] != '=')
-			throw std::runtime_error("'==' or '!=' expected");
-
-		s = StripLeft(s + 2);
-		auto value = ExpectQuoted(s);
+		auto string_filter = ParseStringFilter(s, fold_case);
 		if (*s != ')')
 			throw std::runtime_error("')' expected");
 
@@ -281,13 +339,10 @@ SongFilter::ParseExpression(const char *&s, bool fold_case)
 			type = TAG_NUM_OF_ITEM_TYPES;
 
 		if (type == LOCATE_TAG_FILE_TYPE)
-			return std::make_unique<UriSongFilter>(std::move(value),
-							       fold_case,
-							       negated);
+			return std::make_unique<UriSongFilter>(std::move(string_filter));
 
 		return std::make_unique<TagSongFilter>(TagType(type),
-						       std::move(value),
-						       fold_case, negated);
+						       std::move(string_filter));
 	}
 }
 
@@ -312,19 +367,25 @@ SongFilter::Parse(const char *tag_string, const char *value, bool fold_case)
 		break;
 
 	case LOCATE_TAG_FILE_TYPE:
-		and_filter.AddItem(std::make_unique<UriSongFilter>(value,
-								   fold_case,
-								   false));
+		/* for compatibility with MPD 0.20 and older,
+		   "fold_case" also switches on "substring" */
+		and_filter.AddItem(std::make_unique<UriSongFilter>(StringFilter(value,
+										fold_case,
+										fold_case,
+										false)));
 		break;
 
 	default:
 		if (tag == LOCATE_TAG_ANY_TYPE)
 			tag = TAG_NUM_OF_ITEM_TYPES;
 
+		/* for compatibility with MPD 0.20 and older,
+		   "fold_case" also switches on "substring" */
 		and_filter.AddItem(std::make_unique<TagSongFilter>(TagType(tag),
-								   value,
-								   fold_case,
-								   false));
+								   StringFilter(value,
+										fold_case,
+										fold_case,
+										false)));
 		break;
 	}
 }

src/song/OptimizeFilter.cxx

@@ -58,11 +58,11 @@ OptimizeSongFilter(ISongFilterPtr f) noexcept
 			/* #TagSongFilter has its own "negated" flag,
 			   so we can drop the #NotSongFilter
 			   container */
-			tf->negated = !tf->negated;
+			tf->ToggleNegated();
 			return child;
 		} else if (auto *uf = dynamic_cast<UriSongFilter *>(child.get())) {
 			/* same for #UriSongFilter */
-			uf->negated = !uf->negated;
+			uf->ToggleNegated();
 			return child;
 		}
 

src/song/StringFilter.cxx

@@ -23,17 +23,32 @@
 
 #include <assert.h>
 
-bool
-StringFilter::Match(const char *s) const noexcept
+inline bool
+StringFilter::MatchWithoutNegation(const char *s) const noexcept
 {
 #if !CLANG_CHECK_VERSION(3,6)
 	/* disabled on clang due to -Wtautological-pointer-compare */
 	assert(s != nullptr);
 #endif
 
+#ifdef HAVE_PCRE
+	if (regex)
+		return regex->Match(s);
+#endif
+
 	if (fold_case) {
-		return fold_case.IsIn(s);
+		return substring
+			? fold_case.IsIn(s)
+			: fold_case == s;
 	} else {
-		return StringIsEqual(s, value.c_str());
+		return substring
+			? StringFind(s, value.c_str()) != nullptr
+			: value == s;
 	}
 }
+
+bool
+StringFilter::Match(const char *s) const noexcept
+{
+	return MatchWithoutNegation(s) != negated;
+}

src/song/StringFilter.hxx

@@ -23,7 +23,12 @@
 #include "lib/icu/Compare.hxx"
 #include "util/Compiler.h"
 
+#ifdef HAVE_PCRE
+#include "lib/pcre/UniqueRegex.hxx"
+#endif
+
 #include <string>
+#include <memory>
 
 class StringFilter {
 	std::string value;
@@ -33,18 +38,45 @@ class StringFilter {
 	 */
 	IcuCompare fold_case;
 
+#ifdef HAVE_PCRE
+	std::shared_ptr<UniqueRegex> regex;
+#endif
+
+	/**
+	 * Search for substrings instead of matching the whole string?
+	 */
+	bool substring;
+
+	bool negated;
+
 public:
 	template<typename V>
-	StringFilter(V &&_value, bool _fold_case)
+	StringFilter(V &&_value, bool _fold_case, bool _substring, bool _negated)
 		:value(std::forward<V>(_value)),
 		 fold_case(_fold_case
 			   ? IcuCompare(value.c_str())
-			   : IcuCompare()) {}
+			   : IcuCompare()),
+		 substring(_substring), negated(_negated) {}
 
 	bool empty() const noexcept {
 		return value.empty();
 	}
 
+	bool IsRegex() const noexcept {
+#ifdef HAVE_PCRE
+		return !!regex;
+#else
+		return false;
+#endif
+	}
+
+#ifdef HAVE_PCRE
+	template<typename R>
+	void SetRegex(R &&_regex) noexcept {
+		regex = std::forward<R>(_regex);
+	}
+#endif
+
 	const auto &GetValue() const noexcept {
 		return value;
 	}
@@ -53,8 +85,28 @@ public:
 		return fold_case;
 	}
 
+	bool IsNegated() const noexcept {
+		return negated;
+	}
+
+	void ToggleNegated() noexcept {
+		negated = !negated;
+	}
+
+	const char *GetOperator() const noexcept {
+		return IsRegex()
+			? (negated ? "!~" : "=~")
+			: (substring
+			   ? (negated ? "!contains" : "contains")
+			   : (negated ? "!=" : "=="));
+	}
+
 	gcc_pure
 	bool Match(const char *s) const noexcept;
+
+private:
+	gcc_pure
+	bool MatchWithoutNegation(const char *s) const noexcept;
 };
 
 #endif

src/song/TagSongFilter.cxx

@@ -19,6 +19,7 @@
 
 #include "config.h"
 #include "TagSongFilter.hxx"
+#include "Escape.hxx"
 #include "LightSong.hxx"
 #include "tag/Tag.hxx"
 #include "tag/Fallback.hxx"
@@ -30,7 +31,8 @@ TagSongFilter::ToExpression() const noexcept
 		? "any"
 		: tag_item_names[type];
 
-	return std::string("(") + name + " " + (negated ? "!=" : "==") + " \"" + filter.GetValue() + "\")";
+	return std::string("(") + name + " " + filter.GetOperator()
+		+ " \"" + EscapeFilterString(filter.GetValue()) + "\")";
 }
 
 bool
@@ -88,5 +90,5 @@ TagSongFilter::MatchNN(const Tag &tag) const noexcept
 bool
 TagSongFilter::Match(const LightSong &song) const noexcept
 {
-	return MatchNN(song.tag) != negated;
+	return MatchNN(song.tag);
 }

src/song/TagSongFilter.hxx

@@ -34,17 +34,11 @@ struct LightSong;
 class TagSongFilter final : public ISongFilter {
 	TagType type;
 
-	bool negated;
-
 	StringFilter filter;
 
-	friend ISongFilterPtr OptimizeSongFilter(ISongFilterPtr) noexcept;
-
 public:
-	template<typename V>
-	TagSongFilter(TagType _type, V &&_value, bool fold_case, bool _negated)
-		:type(_type), negated(_negated),
-		 filter(std::forward<V>(_value), fold_case) {}
+	TagSongFilter(TagType _type, StringFilter &&_filter) noexcept
+		:type(_type), filter(std::move(_filter)) {}
 
 	TagType GetTagType() const {
 		return type;
@@ -59,7 +53,11 @@ public:
 	}
 
 	bool IsNegated() const noexcept {
-		return negated;
+		return filter.IsNegated();
+	}
+
+	void ToggleNegated() noexcept {
+		filter.ToggleNegated();
 	}
 
 	ISongFilterPtr Clone() const noexcept override {

src/song/UriSongFilter.cxx

@@ -19,16 +19,18 @@
 
 #include "config.h"
 #include "UriSongFilter.hxx"
+#include "Escape.hxx"
 #include "LightSong.hxx"
 
 std::string
 UriSongFilter::ToExpression() const noexcept
 {
-	return std::string("(file ") + (negated ? "!=" : "==") + " \"" + filter.GetValue() + "\")";
+	return std::string("(file ") + filter.GetOperator()
+		+ " \"" + EscapeFilterString(filter.GetValue()) + "\")";
 }
 
 bool
 UriSongFilter::Match(const LightSong &song) const noexcept
 {
-	return filter.Match(song.GetURI().c_str()) != negated;
+	return filter.Match(song.GetURI().c_str());
 }

src/song/UriSongFilter.hxx

@@ -26,15 +26,9 @@
 class UriSongFilter final : public ISongFilter {
 	StringFilter filter;
 
-	bool negated;
-
-	friend ISongFilterPtr OptimizeSongFilter(ISongFilterPtr) noexcept;
-
 public:
-	template<typename V>
-	UriSongFilter(V &&_value, bool fold_case, bool _negated)
-		:filter(std::forward<V>(_value), fold_case),
-		 negated(_negated) {}
+	UriSongFilter(StringFilter &&_filter) noexcept
+		:filter(std::move(_filter)) {}
 
 	const auto &GetValue() const noexcept {
 		return filter.GetValue();
@@ -45,7 +39,11 @@ public:
 	}
 
 	bool IsNegated() const noexcept {
-		return negated;
+		return filter.IsNegated();
+	}
+
+	void ToggleNegated() noexcept {
+		filter.ToggleNegated();
 	}
 
 	ISongFilterPtr Clone() const noexcept override {

src/song/meson.build

@@ -1,6 +1,7 @@
 song = static_library(
   'song',
   'DetachedSong.cxx',
+  'Escape.cxx',
   'StringFilter.cxx',
   'UriSongFilter.cxx',
   'BaseSongFilter.cxx',
@@ -18,6 +19,7 @@ song_dep = declare_dependency(
   link_with: song,
   dependencies: [
     icu_dep,
+    pcre_dep,
     tag_dep,
     util_dep,
   ],

src/system/FileDescriptor.cxx

@@ -76,7 +76,7 @@ FileDescriptor::IsSocket() const noexcept
 
 #endif
 
-#ifdef __linux
+#ifdef __linux__
 
 bool
 FileDescriptor::Open(FileDescriptor dir, const char *pathname,

src/system/FileDescriptor.hxx

@@ -116,7 +116,7 @@ public:
 		return FileDescriptor(-1);
 	}
 
-#ifdef __linux
+#ifdef __linux__
 	bool Open(FileDescriptor dir, const char *pathname,
 		  int flags, mode_t mode=0666) noexcept;
 #endif

src/zeroconf/ZeroconfGlue.cxx

@@ -32,6 +32,12 @@
 #include <unistd.h>
 #include <limits.h>
 
+#ifndef HOST_NAME_MAX
+/* HOST_NAME_MAX is not a portable macro; it is undefined on some
+   systems */
+#define HOST_NAME_MAX 255
+#endif
+
 static constexpr Domain zeroconf_domain("zeroconf");
 
 /* The default service name to publish

test/.gitignore

@@ -1,2 +0,0 @@
-/run_neighbor_explorer
-/ReadApeTags

test/meson.build

@@ -239,6 +239,7 @@ if enable_database
     '../src/LogBackend.cxx',
     include_directories: inc,
     dependencies: [
+      event_dep,
       storage_glue_dep,
     ],
   )

win32/build.py

@@ -62,7 +62,8 @@ class CrossGccToolchain:
         self.cxxflags = common_flags
         self.cppflags = '-isystem ' + os.path.join(install_prefix, 'include') + \
                         ' -DWINVER=0x0600 -D_WIN32_WINNT=0x0600'
-        self.ldflags = '-L' + os.path.join(install_prefix, 'lib')
+        self.ldflags = '-L' + os.path.join(install_prefix, 'lib') + \
+                       ' -static-libstdc++ -static-libgcc'
         self.libs = ''
 
         self.is_arm = arch.startswith('arm')