Unable to update event

[SteffeyDev]

When I make a change in the Android calendar, it triggers a PUT request, but that request fails with a status of 412 Precondition Failed from my CalDAV server. Based on my reading, this may be because the If-Match value is incorrect. My web proxy logs show the following header for requests that result in 412: "If-Match":["\"\\\"gcs00000001\\\"\"". For PUT requests from my iPhone for the same event, which the server accepts with a 204, the header looks like "If-Match":["\"gcs00000001\""]. Is this a double-escape issue with DavX?

DavX user agent: "User-Agent":["DAVx5/4.4.2-ose (2024/08/08; dav4jvm; okhttp/4.12.0) Android/14"]

[ArnyminerZ]

This is strange, afaik we have not had any other reports of this issue, and it would be a big issue raised on a lot of devices. Can you provide some more debug info? See: https://www.davx5.com/faq/how-to-debug

[SteffeyDev]

I thought it was strange as well, as both DavX and SOGo (my server) are well established. Could still be a server issue, but suspicious that iOS is working fine. Thanks for the instructions, I've attached the log after removing any personal info. Looks like there may be something funny going on with the response from the server, it returns <D:getetag>&#65279;&quot;gcs00000003&quot;</D:getetag> in the REPORT, maybe iOS client strips the extra &quot and DavX doesn't? I don't know the CalDAV protocol, would be happy to report to SOGo if this response does not conform to spec.

davx5-log.txt

[SteffeyDev]

You can see the If-Match: "\"gcs00000000\"" header in the logs, assuming this should be If-Match: "gcs00000000"

[SteffeyDev]

May be related to https://bugs.sogo.nu//view.php?id=5416, I'm going to try updating to the latest version of SOGo, didn't realize the Ubuntu 22 version from APT was from 2022, will report back if this fixes.

[SteffeyDev]

Unfortunately, that ended up being unrelated. I'm now running latest version of SOGo, and it did fix the issues of the of the random  in the getetag, but the issue remains with the double-escape quote resulting in a 412, either because SOGo is returning " characters around the etag value incorrectly in REPORT, or because DavX is failing to strip/handle these " characters appropriately when returning it in the PUT. @ArnyminerZ do you know based on the CalDAV spec whether the issue here lies with SOGo or DavX?

[SteffeyDev]

Actually, with further testing, I can no longer reproduce. I think updating SOGo did fix the issue, but the bad etag was cached in DavX and thus continued to cause issues. Going to close this now. For the next person that installs SOGo on the Ubuntu 22 following the official instructions and runs into this issue on SOGo 5.5, you'll need to switch to Debian 12 to get 5.8, or use the nightly build or build from source to get the latest (which is what I did, 5.11 at the time of writing) to fix this issue.