bug#13449: 24.3.50; Perl mode composed symbols not visible

[Eli Zaretskii]

> Date: Tue, 15 Jan 2013 16:51:17 +0000
> From: Richard Copley <rcopley@gmail.com>
> Cc: 13449@debbugs.gnu.org
> 
> > The following (except that the "=>" is not visible in the Emacs buffer):
> 
> Note: my mail client changed the unicode character U+21D2 (Rightwards
> Double Arrow) to "=" and ">".

No, it didn't.  The text in the buffer is really 2 characters, = and >.  
Emacs converts them to u+21d2 at display time.  (Character compositions
are display-time feature in general.)

> Expanding the composition property (by typing RET on [Show] in the
> pop-up buffer) gives:
> (1 2
>    [8658])

I get

(0 2
       [8658])

but I don't think the difference matters.