Fix noticing of tag chages when MPD database is updated. When comparing songs need to check all fields - not just filename!

ChangeLog

@@ -76,6 +76,8 @@
     workaround applied - revert this before requesting data.
 48. When reading mpd.conf file, if bind_to_address is set to "any", then use
     default of "locahost".
+49. Fix noticing of tag chages when MPD database is updated. When comparing
+    songs need to check all fields - not just filename!
 
 0.7.1
 -----

mpd/song.cpp

@@ -75,41 +75,57 @@ Song & Song::operator=(const Song &s)
 
 bool Song::operator==(const Song &o) const
 {
-    return file == o.file;
+    return 0==compareTo(o);
 }
 
 bool Song::operator<(const Song &o) const
+{
+    return compareTo(o)<0;
+}
+
+int Song::compareTo(const Song &o) const
 {
     bool sortDateBeforeAlbum=MusicLibraryItemAlbum::showDate();
     int compare=albumArtist().localeAwareCompare(o.albumArtist());
 
     if (0!=compare) {
-        return compare<0;
+        return compare;
     }
     if (sortDateBeforeAlbum && year!=o.year) {
-        return year<o.year;
+        return year<o.year ? -1 : 1;
     }
     compare=album.localeAwareCompare(o.album);
     if (0!=compare) {
-        return compare<0;
+        return compare;
     }
     if (!sortDateBeforeAlbum && year!=o.year) {
-        return year<o.year;
+        return year<o.year ? -1 : 1;
     }
     if (disc!=o.disc) {
-        return disc<o.disc;
+        return disc<o.disc ? -1 : 1;
     }
     if (type!=o.type) {
-        return type<o.type;
+        return type<o.type ? -1 : 1;
     }
     if (track!=o.track) {
-        return track<o.track;
+        return track<o.track ? -1 : 1;
     }
-    compare=file.compare(o.file);
+    if (time!=o.time) {
+        return time<o.time ? -1 : 1;
+    }
+    compare=title.localeAwareCompare(o.title);
     if (0!=compare) {
-        return compare<0;
+        return compare;
     }
-    return time<o.time;
+    compare=name.compare(o.name);
+    if (0!=compare) {
+        return compare;
+    }
+    compare=genre.compare(o.genre);
+    if (0!=compare) {
+        return compare;
+    }
+    return file.compare(o.file);
 }
 
 bool Song::isEmpty() const

mpd/song.h

@@ -83,6 +83,7 @@ struct Song
     Song & operator=(const Song &o);
     bool operator==(const Song &o) const;
     bool operator<(const Song &o) const;
+    int compareTo(const Song &o) const;
     virtual ~Song() { }
     bool isEmpty() const;
     void fillEmptyFields();
@@ -111,7 +112,7 @@ Q_DECLARE_METATYPE(Song)
 
 inline uint qHash(const Song &key)
 {
-    return qHash(key.file);
+    return qHash(key.albumArtist()+key.album+key.title+key.file);
 }
 
 inline uint qHash(const Song::AlbumKey &key)