Multiple issues with webcal

[p-fruck]

Hey all,

today I've setup my new phone and for the first time in years I was facing issues with DAVx5 :c

I am using v4.3.16.1-ose from F-Droid. I've connected DAVx5 to my nextcloud and wanted to add the ical calendars of my nextcloud to ICSx5 using the DAVx5 interface. For one of my ical calendars, it worked without any issues. For another calendar, ICSx5 responds with "Couldn't parse iCalendar" (need to investigate, maybe an issue on my side). For the third calender, an invalid url is shared to ICSx5. The url of this calendar required multiple URL parameters, one of which contains a dot (.). The link is terminated right before the dot, so all other url parameters are missing. And now (my personal favorite 😄) I have a fourth calendar that's telling me "No Webcal-capable app found - INSTALL ICSX5". No clue why this happens for one calendar only...

[rfc2822]

Can you try again with DAVx5 4.4? The UI has been rewritten, also for Webcal subscriptions.

For another calendar, ICSx5 responds with "Couldn't parse iCalendar" (need to investigate, maybe an issue on my side).

Please create a posting here for that: https://github.com/bitfireAT/icsx5/discussions

For the third calender, an invalid url is shared to ICSx5. The url of this calendar required multiple URL parameters, one of which contains a dot (.). The link is terminated right before the dot, so all other url parameters are missing.

If this URL still doesn't work with DAVx5 4.4, please provide an anonymized version of the URL here that still shows the problematic characteristics.

[rfc2822]

Regarding the dot: see bitfireAT/icsx5#342

Regarding stripping whitespaces: Hm I don't know… it would then mean to strip whitespaces from all *DAV fields… maybe the server could return a valid URL (one that starts with http(s):// instead of <space>http(s)://) instead? DAVx⁵ passes the URL to an Android Intent, and because no Intent filter is registered for the <space>https:// scheme, it always shows that no app is installed to handle this URI (which is technically correct, but confusing for the user).

[p-fruck]

are you suggesting opening an issue at nextcloud? I am still uncertain whether this is a bug that should be fixed by nextcloud/davx5 or whether it is the users responsibility to provide a clean url?
Also, is there an issue with stripping whitespaces from all DAV fields? Naively, stripping whitespaces from fields like display name/url doesn't sound too bad to me :)

[rfc2822]

Yes, I suggest to strip it on the Nextcloud side, at least additionally. If a server reports an URL in an XML tag like here: <source>...some url...</source> I find it strange to arbitrarily filter the content. To illustrate this: If the XML contains not an URL, but for instance the description , should that be trimmed too? Who says that it's not a user's way of organizing their calendars, with various spaces for whatever reason?

So in general, I tend to trust the server for what it sends in this case.

[p-fruck]

Got it, I'll open an issue at nextcloud within the next couple of days 👍

For another calendar, ICSx5 responds with "Couldn't parse iCalendar" (need to investigate, maybe an issue on my side).

Finally managed to look into this issue, seems like this is another issue with URL parsing. This calendar is an exported nextcloud calendar for which the url follows the schema https://next.cloud/remote.php/dav/public-calendars/<calendar_id>/?export and it seems like url parameters aren't allowed directly after a /. By clicking subscribe in DAVx5 the link shared with ICSx5 becomes https://next.cloud/remote.php/dav/public-calendars/<calendar_id>/ to which nextcloud responds with This is the WebDAV interface. It can only be accessed by WebDAV clients such as the Nextcloud desktop sync client. instead of the exported ical file.
Importing the calendar as https://next.cloud/remote.php/dav/public-calendars/<calendar_id>?export (without a slash in the end) works seemlessly though.

[p-fruck]

nextcloud issue: nextcloud/calendar#6061