Any progress?

I don't, so you have to push. But please test if you find any regressions first. I'm really not sure anymore what those lines were for. I suppose it was some workaround for when no project was selected and stuff wasn't saved properly.

Does Phabricator not preserve the author's email? Use kde AT jbev dot net

• Rename getSelectedProjects() to selectedProjects()

• Fix more code style issues, and also make the whole thing work when there is only one (unselected) project

• Save previous selection, but only use it if nothing else is selected at the moment

• Don't query selected projects twice for no reason

• Add missing change in ProjectTreeView header

Thanks for the review.
I addressed the code style issues and also refactored the plugin a little to get rid of the ugly m_ctxProject altogether. There is no weird internal flip-flop pointer anymore which keeps track of a previous selection. Instead, selections are now queried on demand only.
I think the code flow should be much clearer with this, also in the existing parts. It also makes sure that everything works even when the treeview is manipulated by means other than a right-click menu.

• Fix code style issues and get rid of m_ctxProject pointer

• Remove obsolete disconnect

• Use QPointer instead of relying on signals to reset project pointer

• Also restore treeview after re-configuring CMake/QMake project

• Check for nullptr (should never happen, but check nevertheless for compatibility with external plugins)

• Properly restore state for all projects after restarting KDevelop

Where do you have trailing spaces?
No, I don't have commit access.

I find aligned assignment operators easier to read, but since you seem to prefer not to align them, I changed it (together with the other things you annotated).
And yes, the indentation unit tests pass. ;-)

• Remove unnecessary modelines
• Remove old code paths
• Coding style

Ah, okay. Not very discoverable that feature. Had to search quite a bit.

• Remove debug line

Alright, seems to work. It created a new revision, though: https://phabricator.kde.org/D3105
I guess this one can be discarded then.

Did you try arc from the command-line? See https://community.kde.org/Infrastructure/Phabricator#Posting_Patches.

Hmm. Somehow Phabricator only accepts the first file. The patch contains changes in many files, though. How do I submit the full patch here?