From 1dc2493217afbd68e339b6a855799a19f52b675b Mon Sep 17 00:00:00 2001
From: Marcel Verdult <marcel@verdult.de>
Date: Thu, 12 Nov 2026 13:01:57 +0100
Subject: [PATCH] Persist extra_sf and discovery_mod_timestamp in /prefs.json

NodePrefs::saveSerial()/loadSerial() leave out two fields that the firmware
keeps as live state, so both are reset on every reboot of a node that boots
from /prefs.json:

- discovery_mod_timestamp ("has this node changed since", read by the
  repeater and sensor discovery replies). The legacy binary loader still reads
  it, so it was lost only after the move to /prefs.json.
- extra_sf (side detector spread factors set with "extra.sf"). It was never
  persisted in either format.

Both are now written ("disc_mod" next to the advert intervals, "extra_sf" in
the radio object as hex, like the companion's scope key). The constructor
zeroes extra_sf, which had no initialiser and is now written out.

Compatibility: a file without the keys loads as before, the serializer leaves
a field alone when its key is missing. A firmware that does not know the keys
skips them like any unknown key.
---
 src/helpers/CommonCLI.h | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/src/helpers/CommonCLI.h b/src/helpers/CommonCLI.h
index cb85f6f993..9134bb0897 100644
--- a/src/helpers/CommonCLI.h
+++ b/src/helpers/CommonCLI.h
@@ -99,6 +99,7 @@ class NodePrefs : public ConfigSerializer {
       def("agc_int", _parent->agc_reset_interval);
       def("hash_mode", _parent->path_hash_mode);
       def("multi_ack", _parent->multi_acks);
+      def("extra_sf", (void *) _parent->extra_sf, sizeof(_parent->extra_sf));
     }
   public:
     RadioPrefs(NodePrefs* parent) : _parent(parent) { }
@@ -242,6 +243,7 @@ class NodePrefs : public ConfigSerializer {
     def("owner", owner_info, sizeof(owner_info));
     def("adv_int", advert_interval);
     def("f_adv_int", flood_advert_interval);
+    def("disc_mod", discovery_mod_timestamp);
     def("lat", node_lat);
     def("lon", node_lon);
     def("radio", radio);
@@ -260,6 +262,7 @@ class NodePrefs : public ConfigSerializer {
     guest_password[0] = 0;
     bridge_secret[0] = 0;
     owner_info[0] = 0;
+    memset(extra_sf, 0, sizeof(extra_sf));
   }
 
   CommonRadioPrefs* getRadioPrefs() { return &radio; }