wifi: Fix Duration/ID setting when TXOP Limit is exceeded

src/wifi/model/qos-frame-exchange-manager.cc

@@ -455,13 +455,15 @@ QosFrameExchangeManager::GetFrameDurationId (const WifiMacHeader& header, uint32
       return FrameExchangeManager::GetFrameDurationId (header, size, txParams, fragmentedPacket);
     }
 
+  NS_ASSERT (txParams.m_acknowledgment && txParams.m_acknowledgment->acknowledgmentTime != Time::Min ());
+
   // under multiple protection settings, if the TXOP limit is not null, Duration/ID
   // is set to cover the remaining TXOP time (Sec. 9.2.5.2 of 802.11-2016).
   // The TXOP holder may exceed the TXOP limit in some situations (Sec. 10.22.2.8
   // of 802.11-2016)
   return std::max (m_edca->GetRemainingTxop ()
                    - m_phy->CalculateTxDuration (size, txParams.m_txVector, m_phy->GetPhyBand ()),
-                   Seconds (0));
+                   txParams.m_acknowledgment->acknowledgmentTime);
 }
 
 Time