From 15b3223def5b1b47dd0728a4cc7e9549f0f50899 Mon Sep 17 00:00:00 2001
From: puddly <32534428+puddly@users.noreply.github.com>
Date: Mon, 11 Dec 2023 16:32:50 -0500
Subject: [PATCH] Drop empty frames (#600)

---
 bellows/ezsp/__init__.py | 4 ++++
 tests/test_ezsp.py       | 9 +++++++++
 2 files changed, 13 insertions(+)

diff --git a/bellows/ezsp/__init__.py b/bellows/ezsp/__init__.py
index 2402cd79..b444d5c6 100644
--- a/bellows/ezsp/__init__.py
+++ b/bellows/ezsp/__init__.py
@@ -302,6 +302,10 @@ def frame_received(self, data: bytes) -> None:
             LOGGER.debug("Ignoring frame, protocol is not configured: %r", data)
             return
 
+        if not data:
+            LOGGER.debug("Ignoring empty frame")
+            return
+
         self._protocol(data)
 
     async def get_board_info(
diff --git a/tests/test_ezsp.py b/tests/test_ezsp.py
index 19f97691..6b5c1e96 100644
--- a/tests/test_ezsp.py
+++ b/tests/test_ezsp.py
@@ -863,3 +863,12 @@ async def test_reset_custom_eui64(ezsp_f):
     assert ezsp_f.setTokenData.mock_calls == [
         call(t.NV3KeyId.CREATOR_STACK_RESTORED_EUI64, 0, t.LVBytes32(b"\xFF" * 8))
     ]
+
+
+def test_empty_frame_received(ezsp_f):
+    """Test dropping of invalid, empty frames."""
+    ezsp_f._protocol = MagicMock(spec_set=ezsp_f._protocol)
+    ezsp_f._protocol.__call__ = MagicMock()
+    ezsp_f.frame_received(b"")
+
+    assert ezsp_f._protocol.__call__.mock_calls == []