- Fixed various instances of unused variables, accessing arrays out of bounds, initialization of non-primitive members in constructor's body, dead code, passing parameters by value instead of reference, usage of uninitialized variables, as reported by cppcheck.

src/g_game.cpp

@@ -2589,6 +2589,12 @@ bool G_ProcessIFFDemo (FString &mapname)
 			demo_p = nextchunk;
 	}
 
+	if (!headerHit)
+	{
+		Printf ("Demo has no header!\n");
+		return true;
+	}
+
 	if (!numPlayers)
 	{
 		Printf ("Demo has no players!\n");