Fix crash on scrobbling due to scrobbler methods being called from a thread other than the scrobbler owning thread

This resolves Bug 1675

amarok/src/collectiondb.cpp

@@ -224,8 +224,8 @@ CollectionDB::CollectionDB()
         , m_aftEnabledPersistentTables()
         , m_moveFileJobCancelled( false )
 {
-    // We have our own thread manager
-    disableThreadPostedEvents(true);
+    // Enable cross thread requests for scrobbler
+    connect(this, SIGNAL(startScrobblerSimilarArtistsFetch(const TQString &)), Scrobbler::instance(), SLOT(similarArtists(const TQString &)));
 
     DEBUG_BLOCK
 
@@ -4364,8 +4364,9 @@ CollectionDB::similarArtists( const TQString &artist, uint count )
     values = query( TQString( "SELECT suggestion FROM related_artists WHERE artist = '%1' ORDER BY %2 LIMIT %3 OFFSET 0;" )
                                  .arg( escapeString( artist ), randomFunc(), TQString::number( count ) ) );
 
-    if ( values.isEmpty() )
-        Scrobbler::instance()->similarArtists( artist );
+    if ( values.isEmpty() ) {
+        startScrobblerSimilarArtistsFetch( artist );
+    }
 
     return values;
 }

amarok/src/collectiondb.h

@@ -227,6 +227,9 @@ class LIBAMAROK_EXPORT CollectionDB : public TQObject, public EngineObserver
         void tagsChanged( const TQString &oldArtist, const TQString &oldAlbum );
         void imageFetched( const TQString &remoteURL ); //for fetching remote podcast images
 
+        // Cross-thread communication
+        void startScrobblerSimilarArtistsFetch(const TQString &);
+
     public:
         CollectionDB();
         ~CollectionDB();

amarok/src/scrobbler.h

@@ -34,7 +34,6 @@ class Scrobbler : public TQObject, public EngineObserver
     public:
         static Scrobbler *instance();
 
-        void similarArtists( const TQString & /*artist*/ );
         void applySettings();
 
     signals:
@@ -42,6 +41,7 @@ class Scrobbler : public TQObject, public EngineObserver
 
     public slots:
         void subTrack( long currentPos, long startPos, long endPos ); // cuefiles can update length without track change
+        void similarArtists( const TQString & /*artist*/ );
 
     protected:
         Scrobbler();