Two issues using content scheme to work with files

Steps:

1. I use QML FolderDialog to get access to a folder.
2. I'm trying to create a file in this folder.

First issue: QDir(folderPath).absoluteFilePath("file.txt") returns buggy path which can't be used with QFile. But, just folderPath+"/file.txt" works fine.

Second issue: QFile(path).exists() always returns false. And, when I create a file and write to it, it appends " (1)" to the file name (in case a file with the same name exists already). So, I have no way to overwrite/remove existing file. Is it Qt or Android which appends this? Is it a bug or intended behavior?