Comment 6 for bug 705123

What a mess. Decades ago, the X Window System came with a session-saving protocol which allowed apps to tell the window manager to restore them later. This served Unix and later Linux pretty good for a very long time. Then, a couple years ago, the X-server-based protocol was deemed unacceptable and support was yanked without notice form Gnome and replaced by a new protocol which no application supported, and a big Gnome update was released in that state. Of course, this meant that session-saving was completely broken. Over the past few releases, many (but not all) apps were updated to work with the new Gnome session-saving protocol, and by Ubuntu 10.10 session-saving was useful again. Arguably all that work was pointless to begin with, but now it is completely wasted because session-saving of any kind has been disabled.

We are now just like Windows, with only a manually-maintained list of "startup apps".

The post referenced in comment #4 says that sessions saved under one window manager or session type (unity, etc.) were not compatible with other session types. Well, then why not save sessions independently for each type of session? It would be better to force users to separately set up their session under each scheme than to not allow it at all.

Alternatively, make "save session" an interactive program which grabs the display and lets the user click on each window they want to save, and then creating new entries in the "startup programs" list just as if the user manually entered them. This might avoid all the problems with automatically saving all windows except those which shouldn't be...