Derek, Robin,
This kind of works, so big thanks for the pointers.
In config.php I have:
$conf['multi_login_sites'] = "http://www.domain1.com/index.php|http://www.domain2.com/index.php";
So, no trailing slash (that didn’t work) but as you say, index.php makes it work - kind of.
Firstly, if I login via domain2.com it won’t log me in to domain1.com, but that is OK for now.
Secondly, for my client to see “Edit” links on articles on both sites, he must first login to admin in the usual way, and then go to a second login form hidden on domain2.com. By logging in there, he is then logged in everywhere.
A bit clunky, and I don’t have total confidence in it, but vital for my client to edit some of the 25,000 articles on the sites.
This is our biggest EE job to date: MSM, Amember, OpenAds running three sites containing 16 years of archives for Europe’s No.1 art magazine and art fair run by 40 people. Might as well show you the links seeing as we are in soft-launch (not validated etc yet):
www.frieze.com/magazine/
www.friezeartfair.com
www.friezefoundation.org
There’s a lifetime of case studies, tutorials and warnings in this little lot. Seven months of solid hard work, and a true advertisement for the power of EE I reckon.