Problem download single files that start with underscore
This is mainly due to a problem with the ingestion and this issue address a workaround to fix the problem.
Our users discovered that when they download their data from the data
portal, the file name has an additional underscore at the beginning and
that they cannot open it with PyMca.
The problem is that the ingester adds a /
in Datafile.name which for some reason java replaces the '/' by '_':