Comment 9 for bug 1065979

No, it's not g-s-d, but X that is setting it to mirrored in this case. From the Xorg.0.log, after correctly detecting all the resolutions:

[ 16.904] (II) intel(0): Using fuzzy aspect match for initial modes
[ 16.904] (II) intel(0): Output LVDS1 using initial mode 1024x768
[ 16.904] (II) intel(0): Output VGA1 using initial mode 1024x768

This is the standard default behavior that X.org provides, so is not an X bug. Policy is handled at the gnome-settings-daemon layer, so g-s-d *should* be putting your monitors into the extended configuration by default as per the referenced multi-monitor design specification. X.org does not track power or lid open/closed status so probably couldn't make correct decisions anyway.

Unfortunately a large amount of what's in the specification is the correct design yet simply hasn't been implemented, and that includes this use case. Thus I think this is probably best carried as a wishlist bug for gnome-settings-daemon.

Theoretically we could simply hack X.org to do extended by default (this was experimented with briefly back when RANDR was first introduced). The problem arises that in certain circumstances (e.g. projectors), defaulting to extended can lead to confusing and undesired behaviors; in fact there was discussion at some point by the design team to make mirrored the default again, but I don't know the status on that.

Anyway, if/when this does get implemented, it will probably be too invasive of a change to consider backporting, so the precise and quantal tasks will have to be wontfix. For raring, we have a defined focus for development which excludes development work for multimonitor, so I'll target this bug to S.