Currently if Evolution receives a VCS/ICS attachment, it looks to see if it can find the appointment in a calendar and if so, does not provide the option of adding it to a calendar as it does when it does not find it.

While this works for the simplest use-cases it does not work for more complicated use-cases.

Imagine an executive with a secretary who has read/write access to the executive's calendar along with her own.  A colleague invites both to a meeting.  The executive sees the invitation and accepts and it is added to his calendar (or the secretary does so as his proxy).  The secretary then sees her invitation in her mailbox.  But she doesn't get to add it to her own calendar.  Evolution has "helpfully" noticed it's already in a calendar that she can read/write and assumes she doesn't need it another calendar.

Substitute members of a family who can read/write each other's calendars to keep organized in place of the executive and secretary .  Same problems exists.

I could think of a number of more complicated solutions such as being able to mark calendars as "not mine" so that this helpful "you already have this in your calendar" feature can be more intelligent and allow me to add it to mine.

But even just a static option in every VCS/ICS attachment to add an event to (an) additional calendar(s) even if it was already found would be useful.  Something like:

    Found the appointment in the calendar "Wife's events"
[ ] Add appointment to an additional calendar [ calendar list drop-down ]

The second option with a checkbox operates just like Evolution already normally operates when it doesn't find an event in a calendar.  For bonus points, if the drop-down list could be multi-select to add to several calendars, that would be even better, but that's a stretch goal.

I realize the real Severity: of this issue is probably "enhancement" but this one really is a painful annoyance for anyone who shares calendars (me! me!).  It would be pretty near the top of the "scratch my own itch" hacking projects if I had time for that any more.  I would hope/think that given that all of the code already exists to achieve the above that it would be a 15 minute project for somebody familiar enough with it (and more importantly the GNOME/Gtk development environment to alter the UI accordingly).  :-D