Reporter not subscribed to bug report and doesn't appear to use Launchpad any longer. Last confirmation of this bug was over 11 years ago in comment #1.
Using Firefox 67.0 in Ubuntu 19.10 (dev) I see that entering 'webcal://test' in the URL bar does produce a prompt to use evolution. So closing this as being fixed.
Reporter not subscribed to bug report and doesn't appear to use Launchpad any longer. Last confirmation of this bug was over 11 years ago in comment #1.
Using Firefox 67.0 in Ubuntu 19.10 (dev) I see that entering 'webcal://test' in the URL bar does produce a prompt to use evolution. So closing this as being fixed.