https://bugs.kde.org/show_bug.cgi?id=345830
--- Comment #2 from darkli...@gmail.com ---
I've never worked with KDE source code.
Anyway, I've looked into source code of Okular and I noticed that it's not easy
to implement this feature because a backend for a document is 'queried' by
document type.
https://bugs.kde.org/show_bug.cgi?id=345765
--- Comment #13 from RJVB ---
RIght, it's a cast that's done at runtime, and I'm pretty sure that when I
followed what happened a while ago, the original and cast objects were not at
the same memory address, which is why I wrote the new statement above.
