Hi friends of Thunderbird and connoisseurs of "URLs for everything" ;-) What do you know about nsMsgMailNewsUrl::CloneInternal()? According to the Netwerk guys it's all wrong, the defective clone is an nsIURI object which is lacking most of the properties of the original. If you're interested, head over to https://bugzilla.mozilla.org/show_bug.cgi?id=1432204 and check https://bugzilla.mozilla.org/attachment.cgi?id=8949237. Praise, comments, abuse, insights all welcome. Jörg.