When a file with the `svn:special` property set is not a svn link,
the `svn export` operation will extract a truncated version of that
file if it contains a null byte (see [create_special_file_from_stream](https://github.com/apache/subversion/blob/8baa91d6de143787a7d07b7c1402f636dea9c828/subversion/libsvn_subr/subst.c#L1662-L1739)
implementation in `libsvn_subr/subst.c`).
So ensure to produce the same file as the svn export operation
otherwise the reconstructed file system will differ.
Related to T3695