bugfix: fixed incorrect bytestring encoding PlutusData

pycardano/serialization.py

@@ -176,7 +176,14 @@ def default_encoder(
         # the output bytestring.
         encoder.write(b"\x9f")
         for item in value:
-            encoder.encode(item)
+            if isinstance(item, bytes) and len(item) > 64:
+                encoder.write(b"\x5f")
+                for i in range(0, len(item), 64):
+                    imax = min(i + 64, len(item))
+                    encoder.encode(item[i:imax])
+                encoder.write(b"\xff")
+            else:
+                encoder.encode(item)
         encoder.write(b"\xff")
     elif isinstance(value, RawCBOR):
         encoder.write(value.cbor)

test/pycardano/test_plutus.py

@@ -396,3 +396,25 @@ class A(PlutusData):
     assert (
         res == res2
     ), "Same class has different default constructor id in two consecutive runs"
+
+
+def test_plutus_data_long_bytes():
+    @dataclass
+    class A(PlutusData):
+        a: bytes
+
+    quote = (
+        "The line separating good and evil passes ... right through every human heart."
+    )
+
+    quote_hex = (
+        "d866821a51e835649f5f5840546865206c696e652073657061726174696e6720676f6f6420616e"
+        + "64206576696c20706173736573202e2e2e207269676874207468726f7567682065766572794d"
+        + "2068756d616e2068656172742effff"
+    )
+
+    A_tmp = A(quote.encode())
+
+    assert (
+        A_tmp.to_cbor_hex() == quote_hex
+    ), "Long metadata bytestring is encoded incorrectly."