The cause for this problem has finally been identified. Please follow up at https://github.com/ge0rg/MemorizingTrustManager/issues/52
if davdroid request a GET (http://…/dav/addressbooks/8/1/690b97b7-b5e8-4ebe-b683-00f33481ed2e.vcf) and I response with VCard in the Body - I get an error that ETag is needed.
Where should the ETag be? In the VCard ?
In 0.9.1.2 its working.
The server’s response must contain an ETag header for a GET request, regardless of the client. So this is a server problem.
Sorry for the message and thank you for fast reply.
I added ETag to the header and every thing is fine.
I think a cool feature would be testcases in http/xml for addressbooks, calendars and tasks like: the client send xml and expected that (minimum) answer.
I wrote my own server and my friend was TINE and Wireshark