[O] Emacs master, faces with :extend t let cursor vanish at EOL?!

[Ingo Lohmar]

I am writing to the org-mode list first, because I have only been able
to reproduce this problem in org-mode.

With a recent Emacs master build, faces can have the :extend t property
to indicated that they should extend after the newline.  This is useful
for a user to customize, eg, for `org-block', and it also applies to
default faces like `region', `highlight' or `secondary-selection'.

Using this with a current elpa pkg of org-mode, and setting :extend t on
faces like `org-block`, "often" the cursor vanishes at the EOL of a line
using such a face.  It reliably happens for `org-block', only sometimes
for `secondary-selection'.

Has anybody else experienced that as well, or do you have any pointers
on how to further investigate this?  I think I remember that org-mode does
something with text overlays, but I can't relate that to what I see.

There might also be an issue with face inheritance and the new :extend
attribute --- I might post on emacs-devel to get a better idea of that
as well.

Thanks,
Ingo