When uploading a password protected MS Office file via AOS, its mimetype is set to Unknown, so it is not possible to Edit Online. This doesn't happen when the file is uploaded via Share.
[Steps to reproduce]
1- Set up a vanilla 5.0.1 environment
2- From the client, map a network drive to any AOS accessible folder e.g http://server:port/alfresco/aos/Shared
3- Copy a protected MS Office file to the network drive
4- Try to "Edit Online" the document in Share and check its mimetype
It is possible to "Edit Online" the document, the document's mimetype is Microsoft Excel|Word|PowerPoint 2007.
The "Edit Online" action is not available in Share, the document's mimetype is "Unknown"
[Analysis to date]
When uploading the file via Share, the correct mimetype is detected and "Edit Online" works.
The issue is not reproducible with a non protected file.
Setting manually the mimetype of the file afterwards is not an option for the customer as they want to use this feature for mass file upload.
See attached Fiddler trace and example MS Excel protected file (password=password) for reference.