Steps to Reproduce
Open an email with a text/x-vcard attachment that contains more than one contact. i.e. more than one
BEGIN:VCARD ... END:VCARD. Make sure "Display attachments inline" is checked. I've attached an .eml file with such an attachment which you can open with
mach run as a command line argument.
Note, once Bug 1667716 patch https://phabricator.services.mozilla.com/D118268 lands, an attachment with text/vcard content will also work. In which case you can create the email in Thunderbird (which exports text/vcard content).
The email only shows the message content, but nothing from the attachment inline. Moreover, the email looks like it has no attachments.
Either all the contacts in the attachment to be shown inline. Or the attachment should appear as a regular attachment.
I think this line is the origin of the missing content https://searchfox.org/comm-central/rev/ea1278fae63adcd7fbc22407ff77a9851d38299f/mailnews/addrbook/modules/VCardUtils.jsm#312, which is returned if
VCardUtils.vCardToAbCard(data) throws an error. Doing some debugging, there is indeed an error thrown, with the stack:
TypeError: name.replace is not a function
There's not much to read from the error/stack, other than the method is not built to handle multiple contacts.