Reprocess instead of modifying queued packet

In order to ensure that the traceroute module works correctly, rather
than modifying the hop limnit of the existing queued version of the
packet, simply drop it ifrom the queue and reprocess the version of the
packet with the superior hop limit.

src/mesh/FloodingRouter.cpp

@@ -31,8 +31,11 @@ bool FloodingRouter::shouldFilterReceived(const meshtastic_MeshPacket *p)
                 txRelayCanceled++;
         } else if (iface && p->hop_limit > 0) {
             // If we overhear a duplicate copy of the packet with more hops left than the one we are waiting to
-            // rebroadcast, then update the hop limit of the packet currently sitting in the TX queue.
-            iface->clampHopsToMax(getFrom(p), p->id, p->hop_limit - 1);
+            // rebroadcast, then remove the packet currently sitting in the TX queue and use this one instead.
+            if (iface->removePendingTXPacket(getFrom(p), p->id, p->hop_limit - 1)) {
+                LOG_DEBUG("Processing packet %d again for rebroadcast with with better hop limit (%d)", p->hop_limit - 1);
+                return false;
+            }
         }
         if (config.device.role == meshtastic_Config_DeviceConfig_Role_ROUTER_LATE && iface) {
             iface->clampToLateRebroadcastWindow(getFrom(p), p->id);

src/mesh/MeshPacketQueue.cpp

@@ -113,11 +113,12 @@ meshtastic_MeshPacket *MeshPacketQueue::find(NodeNum from, PacketId id)
 }
 
 /** Attempt to find and remove a packet from this queue.  Returns a pointer to the removed packet, or NULL if not found */
-meshtastic_MeshPacket *MeshPacketQueue::remove(NodeNum from, PacketId id, bool tx_normal, bool tx_late)
+meshtastic_MeshPacket *MeshPacketQueue::remove(NodeNum from, PacketId id, bool tx_normal, bool tx_late, uint8_t hop_limit_lt)
 {
     for (auto it = queue.begin(); it != queue.end(); it++) {
         auto p = (*it);
-        if (getFrom(p) == from && p->id == id && ((tx_normal && !p->tx_after) || (tx_late && p->tx_after))) {
+        if (getFrom(p) == from && p->id == id && ((tx_normal && !p->tx_after) || (tx_late && p->tx_after)) &&
+            (!hop_limit_lt || p->hop_limit < hop_limit_lt)) {
             queue.erase(it);
             return p;
         }

src/mesh/MeshPacketQueue.h

@@ -39,5 +39,6 @@ class MeshPacketQueue
     meshtastic_MeshPacket *find(NodeNum from, PacketId id);
 
     /** Attempt to find and remove a packet from this queue.  Returns the packet which was removed from the queue */
-    meshtastic_MeshPacket *remove(NodeNum from, PacketId id, bool tx_normal = true, bool tx_late = true);
+    meshtastic_MeshPacket *remove(NodeNum from, PacketId id, bool tx_normal = true, bool tx_late = true,
+                                  uint8_t hop_limit_lt = 0);
 };

src/mesh/RadioInterface.h

@@ -185,8 +185,11 @@ class RadioInterface
     /** If the packet is not already in the late rebroadcast window, move it there */
     virtual void clampToLateRebroadcastWindow(NodeNum from, PacketId id) { return; }
 
-    /** Clamp the hop limit to the greater of the hop count provided, or the hop count in the queue */
-    virtual void clampHopsToMax(NodeNum from, PacketId id, uint32_t hop_limit) { return; }
+    /**
+     * If there is a packet pending TX in the queue with a worse hop limit, remove it pending replacement with a better version
+     * @return Whether a pending packet was removed
+     */
+    bool removePendingTXPacket(NodeNum from, PacketId id, uint32_t hop_limit_lt) { return false; }
 
     /**
      * Calculate airtime per

src/mesh/RadioLibInterface.cpp

@@ -345,17 +345,25 @@ void RadioLibInterface::clampToLateRebroadcastWindow(NodeNum from, PacketId id)
 }
 
 /**
- * Clamp the hop limit to the greater of the hop count provided, or the hop count in the queue
+ * If there is a packet pending TX in the queue with a worse hop limit, remove it pending replacement with a better version
+ * @return Whether a pending packet was removed
  */
-void RadioLibInterface::clampHopsToMax(NodeNum from, PacketId id, uint32_t hop_limit)
+bool RadioLibInterface::removePendingTXPacket(NodeNum from, PacketId id, uint32_t hop_limit_lt)
 {
-    meshtastic_MeshPacket *p = txQueue.find(from, id);
-    if (p && p->hop_limit < hop_limit) {
-        LOG_DEBUG("Increasing hop limit for packet from %d to %d", p->hop_limit, hop_limit);
-        p->hop_limit = hop_limit;
+    meshtastic_MeshPacket *p = txQueue.remove(from, id, true, true, hop_limit_lt);
+    if (p) {
+        LOG_DEBUG("Dropping pending-TX packet %d with hop limit %d", p->id, p->hop_limit);
+        packetPool.release(p);
+        return true;
     }
+    return false;
 }
 
+/**
+ * Remove a packet that is eligible for replacement from the TX queue
+ */
+// void RadioLibInterface::removePending
+
 void RadioLibInterface::handleTransmitInterrupt()
 {
     // This can be null if we forced the device to enter standby mode.  In that case

src/mesh/RadioLibInterface.h

@@ -206,7 +206,8 @@ class RadioLibInterface : public RadioInterface, protected concurrency::Notified
     void clampToLateRebroadcastWindow(NodeNum from, PacketId id);
 
     /**
-     * Clamp the hop limit to the greater of the hop count provided, or the hop count in the queue
+     * If there is a packet pending TX in the queue with a worse hop limit, remove it pending replacement with a better version
+     * @return Whether a pending packet was removed
      */
-    void clampHopsToMax(NodeNum from, PacketId id, uint32_t hop_limit);
+    bool removePendingTXPacket(NodeNum from, PacketId id, uint32_t hop_limit_lt);
 };