enable msgpack in zephyr port and add test for it. fix unpack issue

ports/zephyr-cp/boards/adafruit/feather_rp2040_zephyr/autogen_board_info.toml

@@ -71,7 +71,7 @@ memorymap = false
 memorymonitor = false
 microcontroller = true
 mipidsi = false
-msgpack = false
+msgpack = true
 neopixel_write = false
 nvm = true # Zephyr board has nvm
 onewireio = false

ports/zephyr-cp/boards/native/native_sim/autogen_board_info.toml

@@ -56,7 +56,7 @@ i2cdisplaybus = true # Zephyr board has busio
 i2cioexpander = false
 i2ctarget = false
 imagecapture = false
-ipaddress = false
+ipaddress = true # Zephyr networking enabled
 is31fl3741 = false
 jpegio = false
 keypad = false
@@ -71,7 +71,7 @@ memorymap = false
 memorymonitor = false
 microcontroller = true
 mipidsi = false
-msgpack = false
+msgpack = true
 neopixel_write = false
 nvm = true # Zephyr board has nvm
 onewireio = false

ports/zephyr-cp/cptools/build_circuitpython.py

@@ -60,6 +60,7 @@
     "errno",
     "io",
     "math",
+    "msgpack",
 ]
 # Flags that don't match with with a *bindings module. Some used by adafruit_requests
 MPCONFIG_FLAGS = ["array", "errno", "io", "json", "math"]

ports/zephyr-cp/tests/test_msgpack.py

@@ -0,0 +1,137 @@
+# SPDX-FileCopyrightText: 2026 Tim Cocks for Adafruit Industries
+# SPDX-License-Identifier: MIT
+
+"""Test the msgpack module."""
+
+import pytest
+
+
+ROUNDTRIP_CODE = """\
+import msgpack
+from io import BytesIO
+
+obj = {"list": [True, False, None, 1, 3.125], "str": "blah"}
+b = BytesIO()
+msgpack.pack(obj, b)
+encoded = b.getvalue()
+print(f"encoded_len: {len(encoded)}")
+print(f"encoded_hex: {encoded.hex()}")
+
+b.seek(0)
+decoded = msgpack.unpack(b)
+print(f"decoded: {decoded}")
+print(f"match: {decoded == obj}")
+print("done")
+"""
+
+
+@pytest.mark.circuitpy_drive({"code.py": ROUNDTRIP_CODE})
+def test_msgpack_roundtrip(circuitpython):
+    """Pack and unpack a dict containing the basic msgpack types."""
+    circuitpython.wait_until_done()
+
+    output = circuitpython.serial.all_output
+    assert "match: True" in output
+    assert "done" in output
+
+
+USE_LIST_CODE = """\
+import msgpack
+from io import BytesIO
+
+b = BytesIO()
+msgpack.pack([1, 2, 3], b)
+
+b.seek(0)
+as_list = msgpack.unpack(b)
+print(f"as_list: {as_list} type={type(as_list).__name__}")
+
+b.seek(0)
+as_tuple = msgpack.unpack(b, use_list=False)
+print(f"as_tuple: {as_tuple} type={type(as_tuple).__name__}")
+print("done")
+"""
+
+
+@pytest.mark.circuitpy_drive({"code.py": USE_LIST_CODE})
+def test_msgpack_use_list(circuitpython):
+    """use_list=False should return a tuple instead of a list."""
+    circuitpython.wait_until_done()
+
+    output = circuitpython.serial.all_output
+    assert "as_list: [1, 2, 3] type=list" in output
+    assert "as_tuple: (1, 2, 3) type=tuple" in output
+    assert "done" in output
+
+
+EXTTYPE_CODE = """\
+from msgpack import pack, unpack, ExtType
+from io import BytesIO
+
+class MyClass:
+    def __init__(self, val):
+        self.value = val
+
+data = MyClass(b"my_value")
+
+def encoder(obj):
+    if isinstance(obj, MyClass):
+        return ExtType(1, obj.value)
+    return f"no encoder for {obj}"
+
+def decoder(code, data):
+    if code == 1:
+        return MyClass(data)
+    return f"no decoder for type {code}"
+
+buf = BytesIO()
+pack(data, buf, default=encoder)
+buf.seek(0)
+decoded = unpack(buf, ext_hook=decoder)
+print(f"decoded_type: {type(decoded).__name__}")
+print(f"decoded_value: {decoded.value}")
+print("done")
+"""
+
+
+@pytest.mark.circuitpy_drive({"code.py": EXTTYPE_CODE})
+def test_msgpack_exttype(circuitpython):
+    """ExtType with a custom encoder/decoder should round-trip."""
+    circuitpython.wait_until_done()
+
+    output = circuitpython.serial.all_output
+    assert "decoded_type: MyClass" in output
+    assert "decoded_value: b'my_value'" in output
+    assert "done" in output
+
+
+EXTTYPE_PROPS_CODE = """\
+from msgpack import ExtType
+
+e = ExtType(5, b"hello")
+print(f"code: {e.code}")
+print(f"data: {e.data}")
+
+e.code = 10
+print(f"new_code: {e.code}")
+
+try:
+    ExtType(128, b"x")
+except (ValueError, OverflowError) as ex:
+    print(f"range_error: {type(ex).__name__}")
+
+print("done")
+"""
+
+
+@pytest.mark.circuitpy_drive({"code.py": EXTTYPE_PROPS_CODE})
+def test_msgpack_exttype_properties(circuitpython):
+    """ExtType exposes code/data as read/write properties and rejects out-of-range codes."""
+    circuitpython.wait_until_done()
+
+    output = circuitpython.serial.all_output
+    assert "code: 5" in output
+    assert "data: b'hello'" in output
+    assert "new_code: 10" in output
+    assert "range_error:" in output
+    assert "done" in output

shared-module/msgpack/__init__.c

@@ -394,7 +394,9 @@ static mp_obj_t unpack(msgpack_stream_t *s, mp_obj_t ext_hook, bool use_list) {
         size_t len = code & 0b1111;
         mp_obj_dict_t *d = MP_OBJ_TO_PTR(mp_obj_new_dict(len));
         for (size_t i = 0; i < len; i++) {
-            mp_obj_dict_store(d, unpack(s, ext_hook, use_list), unpack(s, ext_hook, use_list));
+            mp_obj_t key = unpack(s, ext_hook, use_list);
+            mp_obj_t value = unpack(s, ext_hook, use_list);
+            mp_obj_dict_store(d, key, value);
         }
         return MP_OBJ_FROM_PTR(d);
     }
@@ -462,7 +464,9 @@ static mp_obj_t unpack(msgpack_stream_t *s, mp_obj_t ext_hook, bool use_list) {
             size_t len = read_size(s, code - 0xde + 1);
             mp_obj_dict_t *d = MP_OBJ_TO_PTR(mp_obj_new_dict(len));
             for (size_t i = 0; i < len; i++) {
-                mp_obj_dict_store(d, unpack(s, ext_hook, use_list), unpack(s, ext_hook, use_list));
+                mp_obj_t key = unpack(s, ext_hook, use_list);
+                mp_obj_t value = unpack(s, ext_hook, use_list);
+                mp_obj_dict_store(d, key, value);
             }
             return MP_OBJ_FROM_PTR(d);
         }