Timing fixes, NULL check

src/mesh/RadioLibInterface.cpp

@@ -252,21 +252,14 @@ void RadioLibInterface::onNotify(uint32_t notification)
             } else {
                 meshtastic_MeshPacket *txp = txQueue.getFront();
                 assert(txp);
-                // check for any remaining delay, and abort if we're still supposed to be waiting
-                if (txp->tx_after > millis()) {
+                long delay_remaining = txp->tx_after ? txp->tx_after - millis() : 0;
+                if (delay_remaining > 0) {
                     // There's still some delay pending on this packet, so resume waiting for it to elapse
-                    notifyLater(txp->tx_after - millis(), TRANSMIT_DELAY_COMPLETED, false);
+                    notifyLater(delay_remaining, TRANSMIT_DELAY_COMPLETED, false);
                 } else {
                     if (isChannelActive()) { // check if there is currently a LoRa packet on the channel
                         startReceive();      // try receiving this packet, afterwards we'll be trying to transmit again
-                        if (txp->tx_after) {
-                            // If we're using the late rebroadcast window, kick it down the road some more
-                            txp->tx_after = max(txp->tx_after, (uint32_t)millis()) +
-                                            (txp->rx_snr ? getTxDelayMsecWeighted(txp->rx_snr) : getTxDelayMsec());
-                            notifyLater(txp->tx_after - millis(), TRANSMIT_DELAY_COMPLETED, false);
-                        } else {
-                            setTransmitDelay();
-                        }
+                        setTransmitDelay();
                     } else {
                         // Send any outgoing packets we have ready as fast as possible to keep the time between channel scan and
                         // actual transmission as short as possible
@@ -293,11 +286,20 @@ void RadioLibInterface::onNotify(uint32_t notification)
 void RadioLibInterface::setTransmitDelay()
 {
     meshtastic_MeshPacket *p = txQueue.getFront();
+    if (!p) {
+        return; // noop if there's nothing in the queue
+    }
+
     // We want all sending/receiving to be done by our daemon thread.
     // We use a delay here because this packet might have been sent in response to a packet we just received.
     // So we want to make sure the other side has had a chance to reconfigure its radio.
 
-    if (p->rx_snr == 0 && p->rx_rssi == 0) {
+    if (p->tx_after) {
+        unsigned long add_delay = p->rx_rssi ? getTxDelayMsecWeighted(p->rx_snr) : getTxDelayMsec();
+        unsigned long now = millis();
+        p->tx_after = max(p->tx_after + add_delay, now + add_delay);
+        notifyLater(now - p->tx_after, TRANSMIT_DELAY_COMPLETED, false);
+    } else if (p->rx_snr == 0 && p->rx_rssi == 0) {
         /* We assume if rx_snr = 0 and rx_rssi = 0, the packet was generated locally.
          *   This assumption is valid because of the offset generated by the radio to account for the noise
          *   floor.
@@ -336,7 +338,7 @@ void RadioLibInterface::clampToLateRebroadcastWindow(NodeNum from, PacketId id)
     // Look for non-late packets only, so we don't do this twice!
     meshtastic_MeshPacket *p = txQueue.remove(from, id, true, false);
     if (p) {
-        p->tx_after = millis() + getTxDelayMsecWeightedWorst(p->rx_snr) + getTxDelayMsecWeighted(p->rx_snr);
+        p->tx_after = millis() + getTxDelayMsecWeightedWorst(p->rx_snr);
         txQueue.enqueue(p);
         LOG_DEBUG("Move existing queued packet to the late rebroadcast window %dms from now", p->tx_after - millis());
     }