From 4d303c95d19905690215f6c462506dd5fbb8cc0a Mon Sep 17 00:00:00 2001
From: Jonathan Bennett <jbennett@incomsystems.biz>
Date: Wed, 7 Jan 2026 16:17:38 -0600
Subject: [PATCH] Add list of text message packet IDs, and check for dupes
 (#9180)

Co-authored-by: Ben Meadors <benmmeadors@gmail.com>
---
 src/mesh/FloodingRouter.cpp       |  5 +++++
 src/modules/TextMessageModule.cpp | 13 +++++++++++++
 src/modules/TextMessageModule.h   |  7 +++++++
 3 files changed, 25 insertions(+)

diff --git a/src/mesh/FloodingRouter.cpp b/src/mesh/FloodingRouter.cpp
index b7459abe0..78602a9ec 100644
--- a/src/mesh/FloodingRouter.cpp
+++ b/src/mesh/FloodingRouter.cpp
@@ -4,6 +4,7 @@
 #include "configuration.h"
 #include "mesh-pb-constants.h"
 #include "meshUtils.h"
+#include "modules/TextMessageModule.h"
 #if !MESHTASTIC_EXCLUDE_TRACEROUTE
 #include "modules/TraceRouteModule.h"
 #endif
@@ -35,6 +36,10 @@ bool FloodingRouter::shouldFilterReceived(const meshtastic_MeshPacket *p)
         return true; // we handled it, so stop processing
     }
 
+    if (!seenRecently && !wasUpgraded && textMessageModule) {
+        seenRecently = textMessageModule->recentlySeen(p->id);
+    }
+
     if (seenRecently) {
         printPacket("Ignore dupe incoming msg", p);
         rxDupe++;
diff --git a/src/modules/TextMessageModule.cpp b/src/modules/TextMessageModule.cpp
index 7f889e087..d94701c6b 100644
--- a/src/modules/TextMessageModule.cpp
+++ b/src/modules/TextMessageModule.cpp
@@ -17,6 +17,9 @@ ProcessMessage TextMessageModule::handleReceived(const meshtastic_MeshPacket &mp
     auto &p = mp.decoded;
     LOG_INFO("Received text msg from=0x%0x, id=0x%x, msg=%.*s", mp.from, mp.id, p.payload.size, p.payload.bytes);
 #endif
+    // add packet ID to the rolling list of packets
+    textPacketList[textPacketListIndex] = mp.id;
+    textPacketListIndex = (textPacketListIndex + 1) % TEXT_PACKET_LIST_SIZE;
 
     // We only store/display messages destined for us.
     devicestate.rx_text_message = mp;
@@ -47,3 +50,13 @@ bool TextMessageModule::wantPacket(const meshtastic_MeshPacket *p)
 {
     return MeshService::isTextPayload(p);
 }
+
+bool TextMessageModule::recentlySeen(uint32_t id)
+{
+    for (size_t i = 0; i < TEXT_PACKET_LIST_SIZE; i++) {
+        if (textPacketList[i] != 0 && textPacketList[i] == id) {
+            return true;
+        }
+    }
+    return false;
+}
\ No newline at end of file
diff --git a/src/modules/TextMessageModule.h b/src/modules/TextMessageModule.h
index e719f1abc..42900a78e 100644
--- a/src/modules/TextMessageModule.h
+++ b/src/modules/TextMessageModule.h
@@ -1,6 +1,7 @@
 #pragma once
 #include "Observer.h"
 #include "SinglePortModule.h"
+#define TEXT_PACKET_LIST_SIZE 50
 
 /**
  * Text message handling for Meshtastic.
@@ -19,6 +20,8 @@ class TextMessageModule : public SinglePortModule, public Observable<const mesht
      */
     TextMessageModule() : SinglePortModule("text", meshtastic_PortNum_TEXT_MESSAGE_APP) {}
 
+    bool recentlySeen(uint32_t id);
+
   protected:
     /** Called to handle a particular incoming message
      *
@@ -27,6 +30,10 @@ class TextMessageModule : public SinglePortModule, public Observable<const mesht
      */
     virtual ProcessMessage handleReceived(const meshtastic_MeshPacket &mp) override;
     virtual bool wantPacket(const meshtastic_MeshPacket *p) override;
+
+  private:
+    uint32_t textPacketList[TEXT_PACKET_LIST_SIZE] = {0};
+    size_t textPacketListIndex = 0;
 };
 
 extern TextMessageModule *textMessageModule;
\ No newline at end of file