Fix song selection in music player window

Selecting a start song when the playlist isn't prepared yet isn't
possible because the `order` list isn't filled and hence the selected
song isn't found.

Make sure we prepare it first and add test for that.

Fixes #1833
Update the translations, fixes #1832

Author: Flamefire

external/languages

@@ -88,6 +88,8 @@ bool Playlist::Load(Log& logger, const boost::filesystem::path& filepath)
 
 void Playlist::SetStartSong(const unsigned id)
 {
+    if(order_.empty())
+        Prepare();
     const auto itEl = helpers::find(order_, id);
     if(itEl != order_.end())
         std::swap(order_.front(), *itEl);

libs/s25main/Playlist.cpp

@@ -1,4 +1,4 @@
-// Copyright (C) 2005 - 2021 Settlers Freaks (sf-team at siedler25.org)
+// Copyright (C) 2005 - 2025 Settlers Freaks (sf-team at siedler25.org)
 //
 // SPDX-License-Identifier: GPL-2.0-or-later
 
@@ -86,15 +86,15 @@ iwMusicPlayer::iwMusicPlayer()
     AddText(ID_txtPlaylist, DrawPoint(20, 240), _("Playlist:"), COLOR_YELLOW, FontStyle{}, NormalFont);
     AddComboBox(ID_cbPlaylist, DrawPoint(20, 260), Extent(330, 22), TextureColor::Green1, NormalFont, 200);
 
-    // Playlistbuttons
+    // Playlist buttons
     const unsigned short button_distance = 10;
     const Extent buttonSize((330 - button_distance) / 2, 22);
     ctrlButton* b1 =
       AddTextButton(ID_btAddPlaylist, DrawPoint(20, 288), buttonSize, TextureColor::Green2, _("Add"), NormalFont);
     AddTextButton(ID_btRemovePlaylist, b1->GetPos() + DrawPoint(buttonSize.x + button_distance, 0), buttonSize,
                   TextureColor::Green2, _("Remove"), NormalFont);
 
-    // Buttons für die Musikstücke
+    // Track buttons
     AddImageButton(ID_btAddTrack, DrawPoint(360, 30), Extent(30, 40), TextureColor::Grey, LOADER.GetImageN("io", 138),
                    _("Add track"));
     AddImageButton(ID_btAddTrackDir, DrawPoint(390, 30), Extent(30, 40), TextureColor::Grey,
@@ -116,7 +116,7 @@ iwMusicPlayer::iwMusicPlayer()
     AddImageButton(ID_btSave, DrawPoint(370, 270), Extent(40, 40), TextureColor::Grey, LOADER.GetImageN("io", 37),
                    _("Save playlist"));
 
-    // Mit Werten füllen
+    // Fill values for current playlist
     UpdateFromPlaylist(MUSICPLAYER.GetPlaylist());
     UpdatePlaylistCombo(SETTINGS.sound.playlist);
     auto* cbPlayList = GetCtrl<ctrlComboBox>(ID_cbPlaylist);
@@ -259,7 +259,7 @@ void iwMusicPlayer::Msg_ButtonClick(const unsigned ctrl_id)
             {
                 const std::string playlistName(GetCtrl<ctrlComboBox>(ID_cbPlaylist)->GetText(*selection));
 
-                // RTTR-Playlisten dürfen nicht gelöscht werden
+                // RTTR-playlists must not be deleted
                 if(isReadonlyPlaylist(playlistName))
                 {
                     WINDOWMANAGER.Show(
@@ -355,18 +355,16 @@ void iwMusicPlayer::Msg_Input(const unsigned win_id, const std::string& msg)
                 valid = true;
             else
             {
-                // Evtl ein Siedlerstück ("sNN")?
+                // Could be an original The settlers song ("sNN")?
                 if(msg.length() == 3 && msg[0] == 's')
                 {
                     if(s25util::fromStringClassicDef(msg.substr(1), 999u) <= 14u)
                         valid = true;
                 }
             }
 
-            // Gültiges Siedlerstück?
             if(valid)
             {
-                // Hinzufügen
                 GetCtrl<ctrlList>(ID_lstSongs)->AddString(msg);
                 changed = true;
             } else
@@ -376,17 +374,15 @@ void iwMusicPlayer::Msg_Input(const unsigned win_id, const std::string& msg)
         break;
         case ID_wndAddPlaylist:
         {
-            // Ungültige Namen ausschließen
+            // Playlist name must start with a letter
             const auto isLetter = [](const char c) { return (c >= 'a' && c <= 'z') || (c >= 'A' && c <= 'Z'); };
             const boost::filesystem::path fullPlaylistPath = GetFullPlaylistPath(msg);
             if(!msg.empty() && isLetter(msg.front()) && Playlist().SaveAs(fullPlaylistPath))
             {
-                // Combobox updaten
                 UpdatePlaylistCombo(fullPlaylistPath.string());
                 changed = true;
             } else
             {
-                // Fehler, konnte nicht gespeichert werden
                 WINDOWMANAGER.Show(std::make_unique<iwMsgbox>(_("Error"), _("The specified file couldn't be saved!"),
                                                               this, MsgboxButton::Ok, MsgboxIcon::ExclamationRed));
             }
@@ -428,7 +424,6 @@ void iwMusicPlayer::SetRandomPlayback(const bool random_playback)
       ->SetTooltip(random_playback ? _("Playback in this order") : _("Random playback"));
 }
 
-/// Updatet die Playlist - Combo
 void iwMusicPlayer::UpdatePlaylistCombo(const std::string& highlight_entry)
 {
     auto* cbPlaylist = GetCtrl<ctrlComboBox>(ID_cbPlaylist);

libs/s25main/ingameWindows/iwMusicPlayer.cpp

@@ -145,4 +145,20 @@ BOOST_AUTO_TEST_CASE(SaveLoadResultsInSamePlaylist)
     BOOST_TEST(helpers::contains(songs, firstSong));
 }
 
+BOOST_AUTO_TEST_CASE(SetNextSong)
+{
+    const std::vector<std::string> songs{"s01", "s02", "s03", "s04", "s05"};
+    Playlist pl(songs, 0, false);
+    BOOST_TEST(pl.getNextSong() == "s01");
+    pl.SetStartSong(3);
+    BOOST_TEST(pl.getNextSong() == "s04");
+    BOOST_TEST(pl.getNextSong() == "s03");
+    BOOST_TEST(pl.getNextSong() == "s02");
+
+    // Works also when playlist was not started yet (see #1833)
+    pl = Playlist(songs, 0, false);
+    pl.SetStartSong(3);
+    BOOST_TEST(pl.getNextSong() == "s04");
+}
+
 BOOST_AUTO_TEST_SUITE_END()