Android port of Emacs

[Eli Zaretskii]

I apologize in advance for not bringing this up earlier.  However,
better late than later or never.

I wonder whether the Android port of Emacs, which is being developed
by Po Lu for the past few months, should be part of the upstream Emacs
and whether it should be distributed as part of the Emacs release
tarballs.  The advantage of having the Android support bundled is that
we allow people to build the Android port right out of the release
tarball.  However, Android is a proprietary platform, so it isn't one
of the systems that we are required to target.  I also don't think
Android (and smartphones in general) will become the main, or even
important, platform for Emacs any time soon.

There are some significant disadvantages of the Android support:

  . it makes the Emacs distribution significantly larger (I think no
    other port, not even the MS-Windows or macOS ports, add so much
    stuff to the distribution)
  . significant portions of the Android support are (and AFAIU must
    be) implemented in Java, which is not used anywhere else in Emacs;
    Emacs developers are therefore not expected to be Java experts,
    and we have no Java-oriented coding conventions in Emacs
  . it requires non-trivial knowledge of the Android platform,
    including its unique requirements and limitations
  . its integration adds some non-trivial hair to many existing Emacs
    APIs and processing, whose purpose is only clear if one considers
    the special Android quirks
  . currently, we have a single developer who understands the
    specifics of the Android port and works on developing it; it is
    not good for Emacs to depend on a single individual for a port
    that should be kept alive and up-to-date for the observable future

Given these IMO significant downsides, I wonder whether we should
maintain the Android support as part of the upstream project.  It
sounds like a non-trivial maintenance burden that relies on a single
developer.  Should we really commit ourselves to this additional work,
from now on?

An alternative would be for the Android support to be a separate
project on Savannah.  Maybe in the long run this would be better?

I think this deserves a serious discussion and a more-or-less
agreed-upon decision, before we decide to land the Android branch and
thus commit ourselves to supporting the Android port.

Once again, apologies for bringing this up so late.  When the work on
this port started, I had no idea the result will be anywhere near
where it is today, or I would speak up much earlier.