Maybe I misunderstand the RFC, but this properties are related to a principal collection. DAVdroid without preemptive authentication doesn't like this and tries to create calendars and addressbooks in /.
DAVdroid dropped support for preemptive authentication in version 1.2.3.
Returning the DAV:unauthenticated pseudo-principal as specified in RFC 5397 doesn't seem to work for DAVdroid.
vobject uses \r\n as line endings. Writing this to a file is not a problem on Linux and newer versions of MacOS. On Windows \r\r\n gets written to disk and on older versions of MacOS \r\r gets written to disk, because python replaces \n by the system depended line ending.
Close the lock file, when no more clients are waiting.
This option is not very useful in general, but on Windows files that are opened cannot be deleted. This causes tests to fail, because the deletion of the temporary filesystem folder fails.
Remove all etags that are directly calculated from data that's read from files.
1. They are not used anywhere (luckily).
2. Etags that are send to clients are calculated from the output of vobject's serialize method. If files are edited externally and vobject normalizes them (like wrapping long lines or replacing all line endings by \r\n), the etags that are sent to the client and the etags that are calculated from raw data will never match. If a new version of vobject is released and the formatting changes slightly, the checks will also always fail.
Disabling syncing increases the risk of data loss when the system crashes or power fails. On the positive it can increase the performance to a great extent.
Unfortunately the library doesn't support disabling of disk syncing, fortunately we only need a small subset of it's functionality which is easy to implement.
