Program: 26123
Project: 26123
Buggy source:
@Override protected UserInfo doInBackground(Void... voids){
  API api=API.GetRightApiForVersion("String_Node_Str",HttpJsonRequest.getInstance().getRootUrl());
  try {
    UserInfo ui=new UserInfo();
    InputStream inputStream=HttpJsonRequest.getInstance().PerformJsonRequest(api.getUserUrl());
    JsonReader reader=new JsonReader(new InputStreamReader(inputStream,"String_Node_Str"));
    reader.beginObject();
    String currentName;
    while (reader.hasNext() && (currentName=reader.nextName()) != null) {
switch (currentName) {
case "String_Node_Str":
        ui.mUserId=reader.nextString();
      break;
case "String_Node_Str":
    ui.mDisplayName=reader.nextString();
  break;
case "String_Node_Str":
com.google.gson.stream.JsonToken jt=reader.peek();
if (jt == com.google.gson.stream.JsonToken.NULL) {
Log.v(TAG,"String_Node_Str");
reader.skipValue();
}
 else {
reader.beginObject();
while (reader.hasNext()) {
  currentName=reader.nextName();
  if (currentName.equals("String_Node_Str")) {
    String encodedImage=reader.nextString();
    byte[] decodedString=Base64.decode(encodedImage,Base64.DEFAULT);
    ui.mAvatar=BitmapFactory.decodeByteArray(decodedString,0,decodedString.length);
    Log.v(TAG,encodedImage);
  }
 else {
    reader.skipValue();
  }
}
}
break;
default :
Log.v(TAG,"String_Node_Str" + currentName);
reader.skipValue();
break;
}
}
reader.close();
return ui;
}
 catch (Exception e) {
if (e.getMessage().equals("String_Node_Str")) {
SharedPreferences mPrefs=PreferenceManager.getDefaultSharedPreferences(NewsReaderListActivity.this);
mPrefs.edit().remove("String_Node_Str").commit();
}
e.printStackTrace();
}
return null;
}

Fixed version (ground truth):
@Override protected UserInfo doInBackground(Void... voids){
  HttpUrl oc_root_url=HttpJsonRequest.getInstance().getRootUrl();
  try {
    String appVersion=OwnCloudReaderMethods.GetVersionNumber(oc_root_url);
    API api=API.GetRightApiForVersion(appVersion,HttpJsonRequest.getInstance().getRootUrl());
    int[] version=API.ExtractVersionNumberFromString(appVersion);
    if (version[0] < 6 || version[0] == 6 && version[1] <= 4)     return null;
    UserInfo ui=new UserInfo();
    InputStream inputStream=HttpJsonRequest.getInstance().PerformJsonRequest(api.getUserUrl());
    JsonReader reader=new JsonReader(new InputStreamReader(inputStream,"String_Node_Str"));
    reader.beginObject();
    String currentName;
    while (reader.hasNext() && (currentName=reader.nextName()) != null) {
switch (currentName) {
case "String_Node_Str":
        ui.mUserId=reader.nextString();
      break;
case "String_Node_Str":
    ui.mDisplayName=reader.nextString();
  break;
case "String_Node_Str":
com.google.gson.stream.JsonToken jt=reader.peek();
if (jt == com.google.gson.stream.JsonToken.NULL) {
Log.v(TAG,"String_Node_Str");
reader.skipValue();
}
 else {
reader.beginObject();
while (reader.hasNext()) {
  currentName=reader.nextName();
  if (currentName.equals("String_Node_Str")) {
    String encodedImage=reader.nextString();
    byte[] decodedString=Base64.decode(encodedImage,Base64.DEFAULT);
    ui.mAvatar=BitmapFactory.decodeByteArray(decodedString,0,decodedString.length);
    Log.v(TAG,encodedImage);
  }
 else {
    reader.skipValue();
  }
}
}
break;
default :
Log.v(TAG,"String_Node_Str" + currentName);
reader.skipValue();
break;
}
}
reader.close();
return ui;
}
 catch (Exception e) {
if (e.getMessage().equals("String_Node_Str")) {
SharedPreferences mPrefs=PreferenceManager.getDefaultSharedPreferences(NewsReaderListActivity.this);
mPrefs.edit().remove("String_Node_Str").commit();
}
e.printStackTrace();
}
return null;
}