Clang-Tidy and Clazy fixes

src/musicbrainz/acoustidclient.cpp

@@ -185,6 +185,7 @@ void AcoustidClient::RequestFinished(QNetworkReply *reply, const int request_id)
   std::stable_sort(id_source_list.begin(), id_source_list.end());
 
   QList<QString> id_list;
+  id_list.reserve(id_source_list.count());
   for (const IdSource &is : id_source_list) {
     id_list << is.id_;
   }

src/musicbrainz/musicbrainzclient.cpp

@@ -433,6 +433,7 @@ MusicBrainzClient::ResultList MusicBrainzClient::ParseTrack(QXmlStreamReader *re
   }
   else {
     std::stable_sort(releases.begin(), releases.end());
+    ret.reserve(releases.count());
     for (const Release &release : releases) {
       ret << release.CopyAndMergeInto(result);
     }
@@ -523,7 +524,7 @@ MusicBrainzClient::ResultList MusicBrainzClient::UniqueResults(const ResultList
 
 }
 
-void MusicBrainzClient::Error(const QString &error, QVariant debug) {
+void MusicBrainzClient::Error(const QString &error, const QVariant &debug) {
 
   qLog(Error) << "MusicBrainz:" << error;
   if (debug.isValid()) qLog(Debug) << debug;

src/musicbrainz/musicbrainzclient.h

@@ -197,7 +197,7 @@ class MusicBrainzClient : public QObject {
   static void ParseArtist(QXmlStreamReader *reader, QString *artist);
   static Release ParseRelease(QXmlStreamReader *reader);
   static ResultList UniqueResults(const ResultList &results, UniqueResultsSortOption opt = SortResults);
-  void Error(const QString &error, QVariant debug = QVariant());
+  void Error(const QString &error, const QVariant &debug = QVariant());
 
  private:
 

src/musicbrainz/tagfetcher.cpp

@@ -142,7 +142,7 @@ void TagFetcher::TagsFetched(const int index, const MusicBrainzClient::ResultLis
 
   const Song &original_song = songs_[index];
   SongList songs_guessed;
-
+  songs_guessed.reserve(results.count());
   for (const MusicBrainzClient::Result &result : results) {
     Song song;
     song.Init(result.title_, result.artist_, result.album_, result.duration_msec_ * kNsecPerMsec);