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

[Eli Zaretskii <eliz@gnu.org>]

> Date: Tue, 15 Jan 2013 16:41:09 +0000
> From: Richard Copley <rcopley@gmail.com>
> Cc: 13449@debbugs.gnu.org
> 
> > When you go to those "space characters" and type "C-u C-x =", what
> > does Emacs say about these two characters in the buffer that it pops
> > up?
> 
> The following (except that the "=>" is not visible in the Emacs buffer):
> 
>              position: 388 of 13355 (3%), column: 34
>             character: = (displayed as =) (codepoint 61, #o75, #x3d)
>     preferred charset: ascii (ASCII (ISO646 IRV))
> code point in charset: 0x3D
>                syntax: . 	which means: punctuation
>              category: .:Base, a:ASCII, l:Latin, r:Roman
>              to input: type "C-x 8 RET HEX-CODEPOINT" or "C-x 8 RET NAME"
>           buffer code: #x3D
>             file code: #x3D (encoded by coding system undecided-dos)
>               display: composed to form "=>" (see below)
> 
> Composed with the following character(s) ">" by the rule:
> 	(?=>)
> The component character(s) are displayed by these fonts (glyph codes):
>  =>: uniscribe:-outline-Source Code Pro-normal-normal-normal-mono-13-*-*-*-c-*-iso10646-1 (#x01)

So it sounds like you have a bad font, which doesn't include a glyph
for this character, but claims it does.

On my machine, Emacs uses the Arial Unicode MS font to show the
character.  If you select the Arial Unicode MS font manually (via
S-mouse-1, for example), does the character display correctly?