Hello!
We are also faced with this issue. Also reproduced on 2.3.2
Database is MySQL 5.5.

+1

Still in 2.3.3a

The reason is that SOGo wrongly encodes CNs of ORGANIZERs and ATTENDEEs in invitation. Please have a look at https://tools.ietf.org/html/rfc5545

cnparam = "CN" "=" param-value
param-value = paramtext / quoted-string
... and so on
There is no encoding with backslashes for CNs with commas. It must be "".

The correct value of CNs with commas is
ORGANIZER;CN="Smith, John":mailto:jsmith@example.com
but SOGo saves
ORGANIZER;CN=Smith\, John:mailto:jsmith@example.com

Please check with outlook. Invitation from outlook (and other calendar-sw) are correct. But answers from SOGo start the process of adding multiple \\.

Will also be cherry-picked in v3.0.3.

This should be fixed in 3.x, too.

Please, this should be fixed in 3.x, too.

Same here (SOGo 3.2.7). Did not report it because there are some more severe problems with SOGo here.
It seems to be an infinite number of "\" after some time. We have seen it in a recurring event with about 10 attendees.

Not the whole content...:

\\\\\\\\\\\\\\\\
\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\
\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\

It's a few megabytes of "\"!

There must be an other unhandled case because that was fixed 1.5 year go.

We will investigate.

I don't think that this was ever fixed in 3.x. Only in 2.x..

The code WAS cherry-picked in v3.

I made a few simple tests in v3 but couldn't reproduce the issue so far.

I'll try with an external Outlook / Exchange invitation.

But not in the GitHub Repo?
https://github.com/inverse-inc/sogo/commits/master/SOPE/NGCards/NSDictionary%2BNGCards.m

Excellent find!

I was looking at similar changes we did in NSString+NGCards.m.

Fix has been cherry-picked.