fix: remove duplicate IANA registry entry causing false update reports

tests/test_iana_update.py

@@ -283,3 +283,42 @@ class TestDiffCalculationEdgeCases:
         assert "0x03" in diff["added"]
         assert "0x02" in diff["deleted"]
         assert "0x01" in diff["modified"]
+
+
+class TestConsecutiveUpdates:
+    """Tests for consecutive IANA updates."""
+
+    def test_consecutive_updates_show_no_changes(self, test_db_path: str) -> None:
+        """Test that second update with same data shows no changes."""
+        xml_path = "tests/fixtures/iana_xml/tls-parameters-minimal.xml"
+
+        with open(xml_path, encoding="utf-8") as f:
+            xml_content = f.read()
+
+        conn = sqlite3.connect(test_db_path)
+        headers = ["Value", "Description", "DTLS", "Recommended", "RFC/Draft"]
+
+        row_count_1, diff_1 = process_registry_with_validation(
+            xml_content,
+            "tls-parameters-4",
+            "iana_tls_cipher_suites",
+            headers,
+            conn,
+            skip_min_rows_check=True,
+        )
+
+        row_count_2, diff_2 = process_registry_with_validation(
+            xml_content,
+            "tls-parameters-4",
+            "iana_tls_cipher_suites",
+            headers,
+            conn,
+            skip_min_rows_check=True,
+        )
+
+        assert row_count_1 == row_count_2
+        assert len(diff_2["added"]) == 0
+        assert len(diff_2["deleted"]) == 0
+        assert len(diff_2["modified"]) == 0
+
+        conn.close()