We should aim to provide the best possible Emacs experience on every platform, so I doubt there will be much opposition to making that cocoa port better. We've discussed with Jan a while back, that it's ok to add OS X-specific features, as long as they are enabled conditionally and the the GNUStep version is not affected by them. 

I suspect that a lot of Emacs users are OS X users these days (many friends of mine who were long-time GNU/Linux users work on OS X today, me included), so the impact of improving the cocoa port can be potentially huge!

On 28 December 2015 at 08:51, YAMAMOTO Mitsuharu <mituharu@math.s.chiba-u.ac.jp> wrote:
>>>>> On Thu, 24 Dec 2015 09:28:35 -0800, John Wiegley <jwiegley@gmail.com> said:

>> The Mac port based on the `emacs-25' branch is now available from
>> https://bitbucket.org/mituharu/emacs-mac.git (the `work' branch)

>> Note that this is a bare development branch and documentations are
>> not updated yet. You don't have to specify --with-mac for configure
>> options because it is the default now.

> Thank you, Yamamoto-san! This is fantastic, and will help me to
> track the latest development more closely than a build I only use
> for testing.

> How much work would it be for us to merge this build flavor into the
> main emacs-25 branch?

Originally, the Mac port was not intended for inclusion to the
main distribution, but for my private and classroom use.  But if
the inclusion is useful and meaningful for many people, then I'll
make some effort to do that.

I have one concern about the inclusion of the Mac port, that is,
whether it can be merged with its full features.  If not, then I'll
have to provide some additional patch anyway, and that's not
beneficial to the current users of the Mac port.  In particular, I
suspect the inclusion of the following features might be controversial
whether they can be regarded as specific to Mac:

  * Pixel-based mouse wheel smooth scroll for newer mice/trackpads.
  * When the clipboard has both textual and image data, yank inserts
    the former and push both into the kill ring so the latter can be
    inserted with yank-pop afterwards.
  * The function `mac-start-animation' provides several animation
    effects via Core Animation.  You can see the default
    animations with buffer switching by horizontal
    swiping/flicking (horizontal movement), exiting from the
    splash screen by typing "q" (fade out), and the "About
    Emacs" (ripple effect) and "Preferences..." menu items (swipe
    effect) in the application menu in the menu bar.
  * Emoji display, with support of variation sequences (text-style
    vs. emoji-style) and modifiers (skin tones) if the font supports
    them.
  * Blend-and-blur of background color on OS X 10.10 and later
    via face's stipple attribute: e.g., (set-face-stipple
    'fringe "alpha:50%").

                                     YAMAMOTO Mitsuharu
                                mituharu@math.s.chiba-u.ac.jp