#2373 DMR stale talker alias

src/main/java/io/github/dsheirer/channel/metadata/ChannelMetadata.java

@@ -1,6 +1,6 @@
 /*
  * *****************************************************************************
- * Copyright (C) 2014-2024 Dennis Sheirer
+ * Copyright (C) 2014-2026 Dennis Sheirer
  *
  * This program is free software: you can redistribute it and/or modify
  * it under the terms of the GNU General Public License as published by
@@ -429,7 +429,7 @@ public class ChannelMetadata implements Listener<IdentifierUpdateNotification>,
                 {
                     if(identifier.getForm() == Form.TALKER_ALIAS)
                     {
-                        mTalkerAliasIdentifier = identifier;
+                        mTalkerAliasIdentifier = update.isAdd() ? identifier : null;
                     }
                     else
                     {

src/test/java/io/github/dsheirer/channel/metadata/ChannelMetadataTest.java

@@ -0,0 +1,108 @@
+/*
+ * *****************************************************************************
+ * Copyright (C) 2014-2026 Dennis Sheirer
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>
+ * ****************************************************************************
+ */
+
+package io.github.dsheirer.channel.metadata;
+
+import io.github.dsheirer.identifier.Form;
+import io.github.dsheirer.identifier.IdentifierClass;
+import io.github.dsheirer.identifier.MutableIdentifierCollection;
+import io.github.dsheirer.identifier.Role;
+import io.github.dsheirer.identifier.alias.DmrTalkerAliasIdentifier;
+import io.github.dsheirer.module.decode.dmr.identifier.DMRRadio;
+import org.junit.jupiter.api.Assertions;
+import org.junit.jupiter.api.BeforeEach;
+import org.junit.jupiter.api.Test;
+
+/**
+ * Tests channel metadata tracking of the FROM talker alias, driven by a mutable identifier collection in the same
+ * way that a decoder state's identifier updates reach the channel metadata in production.
+ */
+public class ChannelMetadataTest
+{
+    private static final int TIMESLOT = 1;
+
+    private ChannelMetadata mChannelMetadata;
+    private MutableIdentifierCollection mIdentifierCollection;
+
+    @BeforeEach
+    public void setup()
+    {
+        mChannelMetadata = new ChannelMetadata(null, TIMESLOT);
+        mIdentifierCollection = new MutableIdentifierCollection(TIMESLOT);
+        mIdentifierCollection.setIdentifierUpdateListener(mChannelMetadata);
+    }
+
+    /**
+     * End of a call as performed by the DMR decoder state: remove the alias and then the FROM radio.
+     */
+    private void endCall()
+    {
+        mIdentifierCollection.remove(IdentifierClass.USER, Form.TALKER_ALIAS, Role.FROM);
+        mIdentifierCollection.remove(Role.FROM);
+    }
+
+    @Test
+    public void talkerAliasIsAvailableWhenAdded()
+    {
+        DmrTalkerAliasIdentifier alias = new DmrTalkerAliasIdentifier("ALPHA");
+        mIdentifierCollection.update(DMRRadio.createFrom(100));
+        mIdentifierCollection.update(alias);
+
+        Assertions.assertTrue(mChannelMetadata.hasTalkerAliasIdentifier());
+        Assertions.assertEquals(alias, mChannelMetadata.getTalkerAliasIdentifier());
+    }
+
+    @Test
+    public void talkerAliasIsClearedWhenRemoved()
+    {
+        mIdentifierCollection.update(DMRRadio.createFrom(100));
+        mIdentifierCollection.update(new DmrTalkerAliasIdentifier("ALPHA"));
+        endCall();
+
+        Assertions.assertFalse(mChannelMetadata.hasTalkerAliasIdentifier());
+        Assertions.assertNull(mChannelMetadata.getTalkerAliasIdentifier());
+    }
+
+    /**
+     * Issue 2373: a radio without a talker alias must not inherit the alias from the previous call on the timeslot.
+     */
+    @Test
+    public void talkerAliasDoesNotCarryOverToNextCall()
+    {
+        mIdentifierCollection.update(DMRRadio.createFrom(100));
+        mIdentifierCollection.update(new DmrTalkerAliasIdentifier("ALPHA"));
+        endCall();
+
+        mIdentifierCollection.update(DMRRadio.createFrom(200));
+
+        Assertions.assertEquals(200, mChannelMetadata.getFromIdentifier().getValue());
+        Assertions.assertFalse(mChannelMetadata.hasTalkerAliasIdentifier());
+    }
+
+    @Test
+    public void talkerAliasIsReplacedWhenUpdated()
+    {
+        DmrTalkerAliasIdentifier bravo = new DmrTalkerAliasIdentifier("BRAVO");
+        mIdentifierCollection.update(DMRRadio.createFrom(100));
+        mIdentifierCollection.update(new DmrTalkerAliasIdentifier("ALPHA"));
+        mIdentifierCollection.update(bravo);
+
+        Assertions.assertEquals(bravo, mChannelMetadata.getTalkerAliasIdentifier());
+    }
+}