From 27eac3d4e548f7dfe5a27349e078b27167f92541 Mon Sep 17 00:00:00 2001
From: Afri <220195275+l5yth@users.noreply.github.com>
Date: Tue, 6 Oct 2026 13:06:43 +0200
Subject: [PATCH] web,data: stop Reticulum destination placeholders from
 renaming (#968)

---
 CHANGELOG.md                                  |   1 +
 data/mesh_ingestor/CONTRACTS.md               |   7 +
 data/mesh_ingestor/protocols/reticulum.py     |   9 +-
 tests/test_reticulum_unit.py                  |  73 ++++++--
 .../application/data_processing/identity.rb   |  58 +++++-
 .../data_processing/node_writes.rb            |  60 ++++---
 web/spec/reticulum_spec.rb                    | 166 +++++++++++++++++-
 7 files changed, 331 insertions(+), 43 deletions(-)

diff --git a/CHANGELOG.md b/CHANGELOG.md
index 87314c38..edbb6e47 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -63,6 +63,7 @@
 * CI: the Python workflow tests Python 3.13 and 3.14; neither CI matrix fails fast (SPEC DP5)
 * Web: a MeshCore channel message heard by two ingestors that resolved its sender to different node ids is stored once (#880)
 * Web: the first boot after upgrading deletes duplicate MeshCore messages once; on instances with several MeshCore ingestors this can remove about a fifth of the stored MeshCore messages (#880)
+* Data/Web: a Reticulum destination's placeholder name never replaces its real name or names its node; a node with no announced name reads its own placeholder; a nameless destination is named from its own hash (SPEC RA10, RE10)
 * Web, bridge, app: Reticulum is named as its own protocol in the bridge tag (`[RT]`), the footer join strip (`RETICULUM_PRESET` and `RETICULUM_FREQ`), the `/nodes` page description and the client fallback label; the site description names no protocol; the app README states the app is Meshtastic only (SPEC RL8)
 * Docs: Reticulum is marked experimental and announce-only; the README says what the RNS stack transmits and that the channel filters ignore it (SPEC RD7/RN5)
 * Nix: the flake ingestor includes `rns`, so `PROTOCOL=reticulum` runs on NixOS; `flake.lock` moves nixpkgs to nixos-unstable of 2026-10-03, which brings Python 3.14 and Ruby 3.4.9 (SPEC DP8)
diff --git a/data/mesh_ingestor/CONTRACTS.md b/data/mesh_ingestor/CONTRACTS.md
index 98fa1f2a..50d81960 100644
--- a/data/mesh_ingestor/CONTRACTS.md
+++ b/data/mesh_ingestor/CONTRACTS.md
@@ -484,6 +484,13 @@ One row per announced destination, newest `last_heard` first.
   body the cursor produced.
 - Fields: `id` (destination hash, hex), `node_id`, `identity_hash`, `name`,
   `aspect`, `role`, `interface`, `first_heard`, `last_heard`, `protocol`.
+- `name` is the destination's announced display name, else `Reticulum` plus the
+  upper-cased first four hex of its own `id`, the placeholder the ingestor sends
+  for a nameless destination on the announce and host paths alike (SPEC RA10).
+  A destination's placeholder is stored on a first sighting, never replaces a
+  stored name and never becomes the node's `long_name`, which is the
+  highest-ranked announced name, else a stored name that is not a placeholder,
+  else the node's own placeholder (SPEC RE10).
 - `identity_hash` groups rows belonging to one peer; several rows share it when
   an identity announces on several aspects.
 - Written only by the node ingest route, from each node record's `destination`
diff --git a/data/mesh_ingestor/protocols/reticulum.py b/data/mesh_ingestor/protocols/reticulum.py
index 5e92cf2c..0f91c86a 100644
--- a/data/mesh_ingestor/protocols/reticulum.py
+++ b/data/mesh_ingestor/protocols/reticulum.py
@@ -600,9 +600,16 @@ def _announce_to_node_dict(
         return None
     hash_hex = _reticulum_hash_hex(dest_hash)
     display_name = _decode_display_name(app_data)
+    # The web stores this name on the destination row, so a placeholder is
+    # built from the destination's own hash, as host discovery builds one
+    # (SPEC RA10(b)). The node id stands in only for an unusable hash, which
+    # writes no destination row; the node's headline comes from RE10.
+    placeholder_id = _reticulum_node_id(dest_hash) or node_id
     user: dict = {
         "longName": (
-            display_name if display_name else _reticulum_placeholder_name(node_id)
+            display_name
+            if display_name
+            else _reticulum_placeholder_name(placeholder_id)
         ),
         "shortName": _reticulum_short_name(node_id),
         "publicKey": _identity_public_key_hex(identity),
diff --git a/tests/test_reticulum_unit.py b/tests/test_reticulum_unit.py
index e1eda4eb..bdea3020 100644
--- a/tests/test_reticulum_unit.py
+++ b/tests/test_reticulum_unit.py
@@ -460,22 +460,24 @@ def test_fallback_name_matches_the_web_placeholder_for_every_id_shape():
     mismatch that breaks ~85% of the id space — which is exactly how the first
     attempt at this fix passed its own test while still clobbering names.
     """
-    for node_id, expected in (
+    identity = _FakeIdentity(bytes.fromhex(_FIELD_PRIMARY))
+    for dest_ref, expected in (
         ("!0001beef", "Reticulum 0001"),  # digits only - matches even lower-cased
         ("!c0ffee00", "Reticulum C0FF"),
         ("!beefcafe", "Reticulum BEEF"),
         ("!deadbeef", "Reticulum DEAD"),
         ("!0000000a", "Reticulum 0000"),
     ):
-        # The placeholder names the row, and the row is keyed on the
-        # identity — so walk identity hashes, not destinations. The expected
+        # The placeholder names the row it lands on, the destination (SPEC
+        # RA10(b)), so walk destination hashes under one identity. The expected
         # strings below are the *web tier's* rule (placeholder_short_id in
-        # identity.rb): first four hex, upper-cased, for reticulum. If the two
-        # sides drift, the web upsert stops recognising these as placeholders
-        # and they start overwriting real display names.
-        idn = _FakeIdentity(bytes.fromhex(node_id[1:] + "11" * 12))
-        node = _announce_to_node_dict(_DEST_HASH, None, identity=idn, last_heard=1)
-        assert node["user"]["longName"] == expected, node_id
+        # identity.rb, which upsert_destination applies to "!" plus the first
+        # eight hex of the destination): first four hex, upper-cased, for
+        # reticulum. If the two sides drift, the web upsert stops recognising
+        # these as placeholders and they start overwriting real display names.
+        dest = bytes.fromhex(dest_ref[1:] + "11" * 12)
+        node = _announce_to_node_dict(dest, None, identity=identity, last_heard=1)
+        assert node["user"]["longName"] == expected, dest_ref
 
 
 # ---------------------------------------------------------------------------
@@ -742,8 +744,11 @@ def test_host_destinations_carry_their_interface_and_announced_name(monkeypatch)
 def test_host_destination_falls_back_to_the_placeholder_without_a_name(monkeypatch):
     """A destination the stack has never heard a name for keeps the placeholder.
 
-    The generic name is wanted -- it is the web upsert's recognised fallback
-    form -- but only where there is no real one to prefer.
+    The generic name is wanted, but only where there is no real one to prefer.
+    The web upsert recognises both placeholder forms, the node id's head and the
+    destination's own head, so it stores this one on a first sighting, never
+    lets it replace a real name, and never lets it head the node, which keeps
+    its own ``Reticulum 2771`` (web/spec/reticulum_spec.rb pins the same string).
     """
     _local_stack(monkeypatch, {_FIELD_LXMF: _FIELD_PRIMARY})
     record = ReticulumProvider().host_destination_nodes()[0]
@@ -754,6 +759,28 @@ def test_host_destination_falls_back_to_the_placeholder_without_a_name(monkeypat
     assert "interface" not in record
 
 
+def test_peer_destination_placeholder_names_its_own_hash():
+    """A nameless peer announce names its destination from that destination.
+
+    SPEC RA10(b): each row is named from its own hash. The host path above
+    does this; the announce path built the fallback from the identity's node
+    id, so the field peer's ``lxmf.delivery`` destination ``4cf985bf...`` was
+    stored as ``Reticulum 2771``, the node's name, instead of its own
+    ``Reticulum 4CF9``. The node keeps its own short name (RA10(a)).
+    """
+    node = _announce_to_node_dict(
+        bytes.fromhex(_FIELD_LXMF),
+        None,
+        identity=_FakeIdentity(bytes.fromhex(_FIELD_PRIMARY)),
+        aspect="lxmf.delivery",
+        last_heard=1,
+    )
+    assert node["nodeId"] == "!27716218"
+    assert node["user"]["shortName"] == "2771"
+    assert node["destination"]["id"] == _FIELD_LXMF
+    assert node["user"]["longName"] == "Reticulum 4CF9"
+
+
 def test_transport_aspect_is_gated_on_transport_enabled(monkeypatch):
     """TRANSPORT is reported only when the stack actually relays traffic.
 
@@ -886,16 +913,23 @@ def test_announce_to_node_dict_public_key_none_when_unreadable():
     assert node["user"]["publicKey"] is None
 
 
-def test_announce_to_node_dict_long_name_falls_back_to_the_node_placeholder():
-    """Undecodable app_data falls back to a placeholder naming the *node*.
+def test_announce_to_node_dict_long_name_falls_back_to_its_destination_placeholder():
+    """Undecodable app_data falls back to a placeholder naming the destination.
 
-    Not the destination: the row is keyed on the identity (SPEC RE7), and the
-    web upsert only yields to the "<Label> <short id>" form it recognises.
+    The web stores this name on the destination row, so it is built from the
+    destination's own hash (SPEC RA10(b)); the node keeps its own headline
+    (RE10). Only an unusable destination hash, which writes no destination
+    row, falls back to the node id's placeholder.
     """
     node = _announce_to_node_dict(
         _DEST_HASH, b"\xff\xfe", identity=_FakeIdentity(), last_heard=1
     )
-    assert node["user"]["longName"] == "Reticulum BEEF"
+    assert node["user"]["longName"] == "Reticulum AABB"
+    salvaged = _announce_to_node_dict(
+        b"\xaa", b"\xff\xfe", identity=_FakeIdentity(), last_heard=1
+    )
+    assert "destination" not in salvaged
+    assert salvaged["user"]["longName"] == "Reticulum BEEF"
 
 
 def test_announce_to_node_dict_omits_hops_when_unknown():
@@ -1407,9 +1441,10 @@ def test_node_snapshot_items_returns_heard_announces(monkeypatch):
     as_dict = dict(items)
     assert set(as_dict) == {"!beef0001", "!c0ffee00"}
     assert as_dict["!beef0001"]["user"]["longName"] == "Alice"
-    # Name-less announce falls back to a placeholder built from its own node
-    # id, so it can never carry another destination's hex.
-    assert as_dict["!c0ffee00"]["user"]["longName"] == "Reticulum C0FF"
+    # Name-less announce falls back to a placeholder built from the
+    # destination it arrived on (SPEC RA10(b)), never from another
+    # destination's hex.
+    assert as_dict["!c0ffee00"]["user"]["longName"] == "Reticulum 1122"
 
 
 def test_update_node_ignores_a_falsy_node_id():
diff --git a/web/lib/potato_mesh/application/data_processing/identity.rb b/web/lib/potato_mesh/application/data_processing/identity.rb
index 032fc28d..39676cc2 100644
--- a/web/lib/potato_mesh/application/data_processing/identity.rb
+++ b/web/lib/potato_mesh/application/data_processing/identity.rb
@@ -183,7 +183,10 @@ module PotatoMesh
       #
       # Must stay in lockstep with the ingestor's own placeholder: this method
       # is what recognises a placeholder so a real name is never overwritten by
-      # one, and a mismatch would silently break that guard.
+      # one, and a mismatch would silently break that guard. The ingestor
+      # builds a nameless Reticulum destination's placeholder from the head of
+      # the destination's own hash, and older ingestors built a peer's from the
+      # head of the node id, so {#reticulum_placeholder_name?} checks both forms.
       #
       # @param node_id [String, nil] canonical node identifier.
       # @param protocol [String, nil] protocol the placeholder belongs to.
@@ -198,6 +201,59 @@ module PotatoMesh
         hex.length >= 4 ? hex[0, 4].upcase : parts[2]
       end
 
+      # Whether +name+ is a generic Reticulum placeholder for a destination of
+      # a node (SPEC RA10).
+      #
+      # Two forms are generic: the head of the destination's own hash,
+      # canonicalised like a node id (+!+ plus its first eight hex digits),
+      # which the ingestor builds for every nameless destination, and the head
+      # of the node id, which older ingestors built for a peer's. Either one is
+      # a stand-in, not an announced name: a destination's placeholder never
+      # replaces its stored name and never names its node, which with no
+      # announced name and no stored real name reads its own placeholder
+      # ({#reticulum_headline_name}).
+      #
+      # @param name [String, nil] candidate name.
+      # @param node_id [String] canonical id of the node owning the destination.
+      # @param destination_id [String, nil] destination hash, hex; +nil+ (no
+      #   usable destination) checks the node id's form only.
+      # @return [Boolean] true when +name+ is either placeholder.
+      def reticulum_placeholder_name?(name, node_id, destination_id)
+        generic_fallback_name?(name, node_id, "reticulum") ||
+          generic_fallback_name?(name, "!#{destination_id.to_s[0, 8]}", "reticulum")
+      end
+
+      # The headline name of a Reticulum node (SPEC RE10 as amended).
+      #
+      # The first announced name among the node's destinations, best ranked
+      # first. A placeholder is not a name, so a nameless +NODE+ aspect cannot
+      # rename a peer whose +PEER+ aspect announced one. With no announced name
+      # a stored headline that is not a placeholder stands; otherwise the node
+      # takes its own placeholder (SPEC RA10(a)): +!27716218+ badges +2771+ and
+      # reads +Reticulum 2771+, never a destination's +Reticulum 9C59+.
+      #
+      # @param node_id [String] canonical node id.
+      # @param destinations [Array<Array(String, String)>] +[id, name]+ pairs of
+      #   the node's destinations, best ranked first.
+      # @param stored [String, nil] the node's current +long_name+.
+      # @return [String, nil] the headline, or nil to leave +long_name+ as it is.
+      def reticulum_headline_name(node_id, destinations, stored)
+        announced = destinations.find do |id, name|
+          string_or_nil(name) && !reticulum_placeholder_name?(name, node_id, id)
+        end
+        return announced.last if announced
+
+        stored = string_or_nil(stored)
+        # A placeholder of the node or of any of its destinations yields; a
+        # real name kept from a record with no usable destination stands.
+        generic = stored.nil? || generic_fallback_name?(stored, node_id, "reticulum") ||
+                  destinations.any? { |id, _name| reticulum_placeholder_name?(stored, node_id, id) }
+        return stored unless generic
+
+        short_id = placeholder_short_id(node_id, "reticulum")
+        short_id ? "#{protocol_display_label("reticulum")} #{short_id}" : stored
+      end
+
       # Resolve a raw node reference to its canonical row in the +nodes+ table.
       #
       # @param db [SQLite3::Database] open database handle.
diff --git a/web/lib/potato_mesh/application/data_processing/node_writes.rb b/web/lib/potato_mesh/application/data_processing/node_writes.rb
index 8722b905..05cedefb 100644
--- a/web/lib/potato_mesh/application/data_processing/node_writes.rb
+++ b/web/lib/potato_mesh/application/data_processing/node_writes.rb
@@ -264,8 +264,12 @@ module PotatoMesh
       # @param destination [Object] +destination+ block from the payload.
       # @param identity_hash [String, nil] identity the destination belongs to.
       # @param name [String, nil] display name announced on this destination;
-      #   a generic +Reticulum <SHORT>+ placeholder is stored as +nil+ so it
-      #   cannot displace a real one.
+      #   a generic +Reticulum <SHORT>+ placeholder, built from this
+      #   destination's own hash or, by an older ingestor, from the node id, is
+      #   stored on a first sighting but never replaces a stored name and never
+      #   names the node; with no announced name the node keeps a stored name
+      #   that is not a placeholder, else reads its own placeholder
+      #   ({#reticulum_placeholder_name?}, {#reticulum_headline_name}).
       # @param interface [String, nil] interface the announce was heard on.
       # @param heard [Integer] unix seconds of receipt.
       # @return [void]
@@ -277,13 +281,14 @@ module PotatoMesh
 
         # A generic "Reticulum <SHORT>" placeholder is still worth storing on a
         # first sighting -- it is what the reader sees until a real name turns
-        # up -- but it must never *replace* one a real announce supplied. The
-        # host's own destinations are discovered rather than announced, so they
-        # fall back to the placeholder whenever the stack remembers no app_data,
-        # and since RE10 derives the node headline from these rows, letting that
-        # land on top of a real name would rename the node too.
+        # up -- but it must never *replace* one a real announce supplied. Every
+        # nameless destination falls back to one, the host's own whenever the
+        # stack remembers no app_data, and letting that land on top of a real
+        # name would erase it; if RE10 had picked that name and another aspect
+        # announced one, the headline would move to that one. Both placeholder
+        # forms count (SPEC RA10).
         stored_name = string_or_nil(name)
-        update_name = generic_fallback_name?(stored_name, node_id, "reticulum") ? nil : stored_name
+        update_name = reticulum_placeholder_name?(stored_name, node_id, id) ? nil : stored_name
 
         params = [
           id,
@@ -350,8 +355,11 @@ module PotatoMesh
       #
       # +name+ and +role+ are resolved independently: an aspect can carry a role
       # while announcing no display name, and taking both from one row would let
-      # a nameless top-ranked aspect blank the headline. Ties break on the more
-      # recently heard destination.
+      # a nameless top-ranked aspect blank the headline. A placeholder is not a
+      # name either (SPEC RE10 as amended): the name is the best-ranked
+      # *announced* one, else a stored name that is not a placeholder, else the
+      # node's own placeholder ({#reticulum_headline_name}). Ties break on the
+      # more recently heard destination.
       #
       # @param db [SQLite3::Database] open database handle.
       # @param node_id [String] canonical id of the node to refresh.
@@ -359,13 +367,15 @@ module PotatoMesh
       def refresh_node_identity_from_destinations(db, node_id)
         rank = DESTINATION_ROLE_RANK_SQL
         with_busy_retry do
-          db.execute(<<~SQL, [node_id, node_id, node_id])
+          destinations = db.execute(<<~SQL, [node_id]).map { |row| row.is_a?(Hash) ? row.values_at("id", "name") : row }
+            SELECT id, name FROM destinations WHERE node_id = ?
+            ORDER BY #{rank}, COALESCE(last_heard, 0) DESC
+          SQL
+          stored = db.get_first_value("SELECT long_name FROM nodes WHERE node_id = ?", [node_id])
+          headline = reticulum_headline_name(node_id, destinations, stored)
+          db.execute(<<~SQL, [headline, node_id, node_id])
             UPDATE nodes SET
-              long_name = COALESCE((
-                SELECT name FROM destinations
-                WHERE node_id = ? AND name IS NOT NULL AND TRIM(name) <> ''
-                ORDER BY #{rank}, COALESCE(last_heard, 0) DESC LIMIT 1
-              ), long_name),
+              long_name = COALESCE(?, long_name),
               role = COALESCE((
                 SELECT role FROM destinations
                 WHERE node_id = ? AND role IS NOT NULL
@@ -488,8 +498,17 @@ module PotatoMesh
         # If the incoming long name is a generic placeholder, prefer any real
         # name already on record so we never stomp known data with fallback
         # text.  For new nodes there is nothing to preserve, so the generic
-        # name is still written via the INSERT VALUES path.
-        long_name_conflict_sql = if generic_fallback_name?(long_name, node_id, protocol)
+        # name is still written via the INSERT VALUES path.  A Reticulum
+        # record's name lands on its destination, so its placeholder may be
+        # built from the destination's own hash rather than the node id
+        # (SPEC RA10); both forms yield.
+        destination = n["destination"]
+        generic_long_name = if protocol == "reticulum"
+            reticulum_placeholder_name?(long_name, node_id, destination.is_a?(Hash) ? destination["id"] : nil)
+          else
+            generic_fallback_name?(long_name, node_id, protocol)
+          end
+        long_name_conflict_sql = if generic_long_name
             # Generic placeholder: keep any real name already on record.
             # COALESCE returns nodes.long_name when non-null, otherwise falls
             # back to the incoming generic — so brand-new nodes still get it.
@@ -619,8 +638,9 @@ module PotatoMesh
                 heard: lh,
               )
               # The headline fields follow the ranked aspect, not the announce
-              # that happened to arrive last (SPEC RE10).
-              refresh_node_identity_from_destinations(db, node_id)
+              # that happened to arrive last (SPEC RE10). Only a Reticulum node
+              # has destinations, so no other protocol pays for the lookups.
+              refresh_node_identity_from_destinations(db, node_id) if protocol == "reticulum"
             end
 
             # Keyed-evidence stamp (SPEC MR1).  Deliberately a separate,
diff --git a/web/spec/reticulum_spec.rb b/web/spec/reticulum_spec.rb
index e2d02a7b..61ed6e93 100644
--- a/web/spec/reticulum_spec.rb
+++ b/web/spec/reticulum_spec.rb
@@ -278,8 +278,9 @@ RSpec.describe "Reticulum protocol support" do
     it "keeps a real destination name when a placeholder arrives later" do
       # Discovery re-emits the host's aspects on every snapshot, falling back to
       # "Reticulum <SHORT>" when the stack remembers no app_data. Arriving after
-      # a real announce, that must not overwrite the stored name -- which would
-      # rename the node too, since RE10 derives the headline from these rows.
+      # a real announce, that must not overwrite the stored name: the
+      # destination row would lose it, though the node keeps its stored
+      # headline (RE10).
       row = post_two_aspects(
         { aspect: "nomadnetwork.node", dest: RETICULUM_DEST_HASH,
           role: "NODE", name: "Department of Decentralization" },
@@ -323,6 +324,167 @@ RSpec.describe "Reticulum protocol support" do
       expect(row["role"]).to eq("NODE")
       expect(row["long_name"]).to eq("Afri Nomad Orion")
     end
+
+    it "does not let a placeholder on a higher aspect rename the node" do
+      # The example above sends name: nil, which no ingestor path sends: a
+      # nameless aspect arrives as a placeholder, built from its own hash
+      # (Reticulum 00FF) or, by an older ingestor, from the node id
+      # (Reticulum A1B2). Neither is a name (SPEC RE10 as amended).
+      observed = ["Reticulum 00FF", "Reticulum A1B2"].to_h do |placeholder|
+        clear_tables
+        row = post_two_aspects(
+          { aspect: "lxmf.delivery", dest: RETICULUM_DEST_HASH,
+            role: "PEER", name: "Afri Nomad Orion" },
+          { aspect: "nomadnetwork.node", dest: RETICULUM_DEST_HASH2,
+            role: "NODE", name: placeholder },
+        )
+        [placeholder, [row["long_name"], row["role"]]]
+      end
+      expect(observed).to eq(
+        "Reticulum 00FF" => ["Afri Nomad Orion", "NODE"],
+        "Reticulum A1B2" => ["Afri Nomad Orion", "NODE"],
+      )
+    end
+
+    it "names a node with no announced name from its own id, not a destination's" do
+      # SPEC RA10(a): the node badges a1b2, so its headline reads Reticulum A1B2
+      # while the destination row keeps its own Reticulum 00FF (RA10(b)). The
+      # aspect is posted twice, as a later snapshot would repeat it.
+      nameless = { aspect: "nomadnetwork.node", dest: RETICULUM_DEST_HASH2,
+                   role: "NODE", name: "Reticulum 00FF" }
+      row = post_two_aspects(nameless, nameless)
+      with_db(readonly: true) do |db|
+        destination = db.get_first_value(
+          "SELECT name FROM destinations WHERE id = ?", [RETICULUM_DEST_HASH2]
+        )
+        expect([destination, row["long_name"]]).to eq(["Reticulum 00FF", "Reticulum A1B2"])
+      end
+    end
+  end
+
+  describe "headline name fallback (SPEC RE10, RA10)" do
+    it "keeps a real name the node carries when a nameless destination arrives" do
+      # A record with an unusable destination hash names the node but writes no
+      # destination row; a later nameless destination must not erase that name.
+      register_reticulum_ingestor
+      named = reticulum_node_fixture(last_heard: now - 30).except("destination")
+      nameless = reticulum_node_fixture(last_heard: now - 29, aspect: "nomadnetwork.node",
+                                        dest_id: RETICULUM_DEST_HASH2, role: "NODE")
+      nameless["user"]["longName"] = "Reticulum 00FF"
+      [named, nameless].each do |record|
+        payload = { RETICULUM_NODE_ID => record, "ingestor" => RETICULUM_INGESTOR_ID, "protocol" => "reticulum" }
+        post "/api/nodes", payload.to_json, auth_headers
+        expect(last_response.status).to eq(201)
+      end
+      with_db(readonly: true) do |db|
+        expect(
+          db.get_first_value("SELECT long_name FROM nodes WHERE node_id = ?", [RETICULUM_NODE_ID]),
+        ).to eq("Argos Station")
+      end
+    end
+
+    it "gives a node with no name at all its own placeholder" do
+      expect(reticulum_headline_name(RETICULUM_NODE_ID, [], nil)).to eq("Reticulum A1B2")
+    end
+
+    it "leaves the name alone for an id it cannot read" do
+      expect(reticulum_headline_name("not-a-node-id", [], nil)).to be_nil
+    end
+
+    it "reads destination rows from a hash-results handle" do
+      register_reticulum_ingestor
+      post_reticulum_nodes
+      with_db do |db|
+        db.execute("UPDATE nodes SET long_name = 'Reticulum A1B2' WHERE node_id = ?", [RETICULUM_NODE_ID])
+        refresh_node_identity_from_destinations(db, RETICULUM_NODE_ID)
+        expect(
+          db.get_first_value("SELECT long_name FROM nodes WHERE node_id = ?", [RETICULUM_NODE_ID]),
+        ).to eq("Argos Station")
+      end
+    end
+  end
+
+  describe "host destination placeholders (SPEC RA10)" do
+    # The field host: node !27716218 (RETICULUM_IDENTITY_HASH) and two of the
+    # destinations RNS derives from that identity, so neither shares the node's
+    # head. The ingestor names a nameless destination from its own hash
+    # (RA10): "Reticulum 4CF9" and "Reticulum 9C59", not the node's
+    # "Reticulum 2771". tests/test_reticulum_unit.py pins the same string for
+    # the same pair. RETICULUM_DEST_HASH starts like RETICULUM_NODE_ID and
+    # cannot tell the two forms apart.
+    RETICULUM_HOST_NODE_ID = "!27716218".freeze
+    RETICULUM_HOST_LXMF = {
+      "id" => "4cf985bf933c21b1aa8dabd407d4ef69", "aspect" => "lxmf.delivery", "role" => "PEER",
+    }.freeze
+    RETICULUM_HOST_NOMADNET = {
+      "id" => "9c59da5e1516745d74cc908243e0ba2b", "aspect" => "nomadnetwork.node", "role" => "NODE",
+    }.freeze
+
+    # POST host-destination records one at a time, each shaped as
+    # _host_destination_nodes builds it (no publicKey, no hopsAway), and read
+    # back what they left behind.
+    #
+    # @param records [Array<Array(Hash, String)>] destination block and
+    #   user.longName pairs, oldest first.
+    # @return [Array(Hash{String => String}, String)] the stored destination
+    #   names keyed by destination id, and the node's long_name.
+    def post_host_destinations(*records)
+      register_reticulum_ingestor
+      records.each_with_index do |(destination, name), index|
+        payload = {
+          RETICULUM_HOST_NODE_ID => {
+            "nodeId" => RETICULUM_HOST_NODE_ID,
+            "lastHeard" => now - 30 + index,
+            "protocol" => "reticulum",
+            "identityHash" => RETICULUM_IDENTITY_HASH,
+            "destination" => destination,
+            "user" => { "shortName" => "2771", "longName" => name, "role" => destination["role"] },
+          },
+          "ingestor" => RETICULUM_INGESTOR_ID,
+          "protocol" => "reticulum",
+        }
+        post "/api/nodes", payload.to_json, auth_headers
+        expect(last_response.status).to eq(201)
+      end
+      with_db(readonly: true) do |db|
+        names = db.execute("SELECT id, name FROM destinations").to_h { |r| [r["id"], r["name"]] }
+        headline = db.get_first_value(
+          "SELECT long_name FROM nodes WHERE node_id = ?", [RETICULUM_HOST_NODE_ID]
+        )
+        [names, headline]
+      end
+    end
+
+    it "never lets a destination-derived placeholder replace a real name" do
+      # The second record is a later snapshot whose stack remembers no app_data
+      # for the destination.
+      names, headline = post_host_destinations(
+        [RETICULUM_HOST_LXMF, "Afri Nomad Orion"],
+        [RETICULUM_HOST_LXMF, "Reticulum 4CF9"],
+      )
+      expect([names[RETICULUM_HOST_LXMF["id"]], headline]).to eq(["Afri Nomad Orion", "Afri Nomad Orion"])
+    end
+
+    it "keeps the ranked headline when its aspect falls back to the placeholder" do
+      # NODE outranks PEER (RE10); without the guard a placeholder landing on
+      # the NODE row erases its real name and the headline moves to PEER's.
+      names, headline = post_host_destinations(
+        [RETICULUM_HOST_NOMADNET, "Department of Decentralization"],
+        [RETICULUM_HOST_LXMF, "Afri Nomad Orion"],
+        [RETICULUM_HOST_NOMADNET, "Reticulum 9C59"],
+      )
+      expect([names[RETICULUM_HOST_NOMADNET["id"]], headline]).to eq(
+        ["Department of Decentralization", "Department of Decentralization"],
+      )
+    end
+
+    it "stores a destination-derived placeholder on a first sighting" do
+      # The generic name is wanted where there is no real one to prefer, on the
+      # destination row only: the node keeps its own placeholder, which its
+      # badge 2771 matches (RA10(a), RE10).
+      names, headline = post_host_destinations([RETICULUM_HOST_LXMF, "Reticulum 4CF9"])
+      expect([names[RETICULUM_HOST_LXMF["id"]], headline]).to eq(["Reticulum 4CF9", "Reticulum 2771"])
+    end
   end
 
   describe "GET /api/destinations" do