emacs26-app update-alternatives is broken

[nieder]

Following thread on fink-users, the update-alternatives for emacs26-app is broken. The breakage was ignored with dpkg1.10, but is fatal with dpkg1.16

The breakage happens because u-a was told to look for all managed files inside the emacs.app bundle which was true for emacs23-app. However, that's not the case with emacs26-app, where only Emacs itself is inside the .app bundle and the expected managed files are in %p/bin and %p/share/man (and there's a versioned emacs-%v in %p/bin).

The various emacs can't coexist (they all conflics/replaces each other). Why do we use update-alternatives then if we don't need to pick one flavor out of many installed ones to be linked to the unversioned command(s) ?

Assuming there's a good reason to keep using u-a,

1. why are the various managed files split among multiple u-a calls, instead of using the --slave option from a single u-a call?
2. why do the different u-a calls have different priorities? In emacs26-app, most are at '40', but etags is at '60'. And in emacs26, most have a priority of '50', but again etags is higher at '70'.

[okayamat]

I am not sure why almost update-alternatives point %p/Applications/Emacs.app/Contents/MacOS/bin .
There are no such binaries, even no such a directory.
For a test, I've just commented out those update-alternatives except %p/Applications/Emacs.app/Contents/MacOS/Emacs, and it worked fine.
emacs26-app.txt