I have got the same problem. I installed owncloud in a subdirectory so my adress to owncloud is https://domain.de/owncloud
I have already modified the two needed lines in the .htaccess file:
RewriteRule ^.well-known/carddav /owncloud/remote.php/carddav/ [R=301,L]
RewriteRule ^.well-known/caldav /owncloud/remote.php/caldav/ [R=301,L]
When I type the URL in a webbrowser I get redirectet. When I use Davdroid with https://domain.de/owncloud/ it says there are no calendars or contacts found.
So I have to add a davdroid account for my calendars and an account for my contacts typing in the full adress (for calendars: https://domain.de/owncloud/remote.php/caldav and for contacts: https://domain.de/owncloud/remote.php/carddav )
If I install owncloud in a subdomain like https://oc.domain.de and also use https://oc.domain.de in davdroid then davdroid immediately finds my calendars and contacts so I can add them with one davdroid account and thats what I want to have.
So I guess Davdroid is looking for the false adress when using owncloud in a subdirectory.
The rest of my rewrite rules (just to be sure):
<IfModule mod_rewrite.c>
RewriteEngine on
RewriteCond %{SERVER_PORT} !^443$
RewriteRule ^ https://%{HTTP_HOST}%{REQUEST_URI} [L,R=301,NE]
RewriteRule .* - [env=HTTP_AUTHORIZATION:%{HTTP:Authorization}]
RewriteRule ^.well-known/host-meta /owncloud/public.php?service=host-meta [QSA,L]
RewriteRule ^.well-known/host-meta.json /owncloud/public.php?service=host-meta-json [QSA,L]
RewriteRule ^.well-known/carddav /owncloud/remote.php/carddav/ [R=301,L]
RewriteRule ^.well-known/caldav /owncloud/remote.php/caldav/ [R=301,L]
RewriteRule ^apps/calendar/caldav.php /owncloud/remote.php/caldav/ [QSA,L]
RewriteRule ^apps/contacts/carddav.php /owncloud/remote.php/carddav/ [QSA,L]
RewriteRule ^remote/(.) /owncloud/remote.php [QSA,L]
RewriteRule ^(build|tests|config|lib|3rdparty|templates)/. - [R=404,L]
RewriteRule ^(.|autotest|occ|issue|indie|db_|console).* - [R=404,L]
</IfModule>
Here are my records: 0_1456782402372_davdroid-debug616227045.txt
If I get the records right, then davdroid is looking for
[trace] --> OPTIONS https://domain.de/owncloud/ HTTP/1.1
but shouldn’t this adress rather be
[trace] --> OPTIONS https://domain.de/owncloud/.well-known/carddav HTTP/1.1
and
[trace] --> OPTIONS https://domain.de/owncloud/.well-known/caldav HTTP/1.1
because otherwise a redirect in the .htaccess redirects the query to the false adress:
[trace] Location: https://domain.de/owncloud/index.php/apps/files/
As a workaround I could create a .htaccess in my root with the following content:
<IfModule mod_rewrite.c>
RewriteEngine on
RewriteCond %{SERVER_PORT} !^443$
RewriteRule ^ https://%{HTTP_HOST}%{REQUEST_URI} [L,R=301,NE]
RewriteRule ^.well-known/host-meta /owncloud/public.php?service=host-meta [QSA,L]
RewriteRule ^.well-known/host-meta.json /owncloud/public.php?service=host-meta-json [QSA,L]
RewriteRule ^.well-known/carddav /owncloud/remote.php/carddav/ [R=301,L]
RewriteRule ^.well-known/caldav /owncloud/remote.php/caldav/ [R=301,L]
</IfModule>
This works because davdroid tries to find the owncloud calendar and contacts in https://domain.de after it didn’t find anything in https://domain.de/owncloud/