No person shall be held liable for damages or penalties for any act or failure to act resulting directly or indirectly from compliance with a rule, regulation, or order issued pursuant to this chapter, notwithstanding that any such rule, regulation, or order shall thereafter be declared by judicial or other competent authority to be invalid. No person shall discriminate against orders or contracts to which priority is assigned or for which materials or facilities are allocated under subchapter I of this chapter or under any rule, regulation, or order issued thereunder, by charging higher prices or by imposing different terms and conditions for such orders or contracts than for other generally comparable orders or contracts, or in any other manner.