Export, Trackgain: Empty string instead of 0.0000

src/AudioDisplayUtils.pas

@@ -397,8 +397,8 @@ function GetAudioProperty(aAudioFile: TAudioFile; aProp: TEAudioProperty): strin
       cpLyrics : result := aAudioFile.Lyrics;
       cpLyricsExist : if aAudioFile.LyricsExisting then result := '1' else result := '0';
       cpBPM : result := aAudioFile.BPM;
-      cpTrackGain : result := PeakValueToString(aAudioFile.TrackGain);
-      cpAlbumGain : result := PeakValueToString(aAudioFile.AlbumGain);
+      cpTrackGain : result := GainValueToNumberString(aAudioFile.TrackGain);
+      cpAlbumGain : result := GainValueToNumberString(aAudioFile.AlbumGain);
       cpTrackPeak : result := PeakValueToString(aAudioFile.TrackPeak);
       cpAlbumPeak : result := PeakValueToString(aAudioFile.AlbumPeak);
       cpCoverID : result := aAudioFile.CoverID;

src/Hilfsfunktionen.pas

@@ -90,6 +90,7 @@ function GainStringToSingle(aGainString: String): Single;
 function PeakStringToSingle(aPeakString: String): Single;
 
 function GainValueToString(aGainValue: Single): String;
+function GainValueToNumberString(aGainValue: Single): String;
 function PeakValueToString(aPeakValue: Single): String;
 
 function AnsiCompareText_Nemp(const S1, S2: string): Integer;
@@ -763,6 +764,22 @@ function GainValueToString(aGainValue: Single): String;
     end;
 end;
 
+function GainValueToNumberString(aGainValue: Single): String;
+var formatSettings: TFormatSettings;
+begin
+    if isZero(aGainValue) then
+        result := ''
+    else
+    begin
+        formatSettings := TFormatSettings.Create(GetThreadLocale);
+        formatSettings.DecimalSeparator := '.';
+        if aGainValue > 0 then
+            result := Format('+%.6f', [aGainValue], formatSettings)
+        else
+            result := Format('%.6f', [aGainValue], formatSettings);
+    end;
+end;
+
 function PeakValueToString(aPeakValue: Single): String;
 var formatSettings: TFormatSettings;
 begin