bug#7840: SYMBOL_VALUE in terminal.c (was 23.2.91; default-terminal-coding-system not inherited by created terminals)

[Eli Zaretskii <eliz@gnu.org>]

> From: Stefan Monnier <monnier@iro.umontreal.ca>
> Cc: Eli Zaretskii <eliz@gnu.org>,  7840@debbugs.gnu.org
> Date: Mon, 14 Feb 2011 13:05:44 -0500
> 
> >> * terminal.c (create_terminal): Use default-keyboard-coding-system
> >> and default-terminal-coding-system to initialize coding systems of
> >> the new terminal.  (Bug#7840)
> >> 
> >> !   keyboard_coding = SYMBOL_VALUE (intern ("default-keyboard-coding-system"));
> >> !   if (NILP (keyboard_coding)
> >> !       || EQ (keyboard_coding, Qunbound)
> >> !       || NILP (Fcoding_system_p (keyboard_coding)))
> >> !     keyboard_coding = Qno_conversion;
> >> !   terminal_coding = SYMBOL_VALUE (intern ("default-terminal-coding-system"));
> 
> > This change doesn't build on the trunk, due to Stefan's 2010-04-20
> > change removing SYMBOL_VALUE.
> 
> > I left out this change when doing the last merge from the branch.  Would
> > you mind working up a separate patch and applying it to the trunk?
> > (Fsymbol_value apparently doesn't work here, because the symbols can be
> > unbound and we don't want to signal an error.)
> 
> We can just use Fboundp tests, when needed.

I used find_symbol_value instead, which seems to be the Emacs 24
equivalent of SYMBOL_VALUE in this situation.

Committed to the trunk.