hangup tweaks (trunk only)

Fix a typo in some conditional (NOSAVEONHANGUP) code, and tweak
SAFERHANGUP so that it doesn't defer hangup handling if the game hasn't
started yet or has already finished (it's possible to be waiting for a
--More-- prompt at end of game code before the hangup handler is reset,
so the regular handler could be called in that state).  Also, undefine
SAFERHANGUP if NOSAVEONHANGUP is defined, since there's no point in
deferring hangup for the latter.

include/global.h

@@ -272,7 +272,7 @@ typedef char nhptext;
 #if defined(UNIX) || defined(VMS) || defined(__EMX__) || defined(WIN32)
 # define HANGUPHANDLING
 #endif
-#if defined(SAFERHANGUP) && !defined(HANGUPHANDLING)
+#if defined(SAFERHANGUP) && (defined(NOSAVEONHANGUP) || !defined(HANGUPHANDLING))
 # undef SAFERHANGUP
 #endif
 

src/cmd.c

@@ -2798,6 +2798,9 @@ parse()
 }
 
 #ifdef HANGUPHANDLING
+/* some very old systems, or descendents of such systems, expect signal
+   handlers to have return type `int', but they don't actually inspect
+   the return value so we should be safe using `void' unconditionally */
 /*ARGUSED*/
 void
 hangup(sig_unused) /* called as signal() handler, so sent at least one arg */
@@ -2812,16 +2815,17 @@ int sig_unused;
 	   but also potentially riskier because the disconnected program
 	   must continue running longer before attempting a hangup save. */
 	program_state.done_hup++;
-# else
+	/* defer hangup iff game appears to be in progress */
+	if (program_state.something_worth_saving) return;
+# endif /* SAFERHANGUP */
 	end_of_input();
-# endif /* ?SAFERHANGUP */
 }
 
 void
 end_of_input()
 {
 # ifdef NOSAVEONHANGUP
-	program_state_something_worth_saving = 0;
+	program_state.something_worth_saving = 0;
 # endif
 # ifndef SAFERHANGUP
 	if (!program_state.done_hup++)