bug#20537: 25.0.50; `compose-string-internal` does not work properly on OSX.

[Keith David Bershatsky]

I was not able to get this `test-fn` example to work using the latest Emacs 
Trunk built early in the morning on May 12, 2015.  The echo area should display 
the capital letter A with a vertical pipe running through the very center of 
the letter; however, the pipe is not even visible -- just the letter A appears 
in the echo area.

I am using OSX Snow Leopard 10.6.8:  GNU Emacs 25.0.50.1 
(x86_64-apple-darwin10.8.0, NS appkit-1038.36 Version 10.6.8 (Build 10K549)) of 
2015-05-12 on server.local

Keith

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At Sun, 10 May 2015 19:34:01 +0200,
Jan D. wrote:
> 
> Fixed in trunk.
> 
>       Jan D.
> 
> > 9 maj 2015 kl. 20:27 skrev Keith David Bershatsky <esq@lawlist.com>:
> > 
> > The function `compose-string-internal` does not work properly when running 
> > Emacs built on OSX.  The following example works on Windows, but not OSX -- 
> > it "should be" the letter A with a pipe running through the center of the 
> > letter A.  Depending upon the arguments passed to `compose-string-internal` 
> > when using Emacs on OSX, the pipe is either displayed to the right (at 
> > various distances) or is not visible at all -- it never displays "on top 
> > of" the target character.
> > 
> > (defun test-fn ()
> > (interactive)
> >  (message (compose-string-internal "A|" 0 (length "A|"))))
> > 
> > And here is another version of the same concept using `compose-chars`, 
> > which uses `compose-string-internal`.
> > 
> > (defun test-fn ()
> > (interactive)
> >  (message (compose-chars (string-to-char "A") '(tc . tc) (string-to-char 
> > "|"))))
> > 
> > Thanks,
> > 
> > Keith