Allow recovery from corrupted items in Enum.read_many()

test/test_enums.py

@@ -0,0 +1,40 @@
+import unittest
+
+from xpdt import NameSpace, StructDef, MemberDef, BaseType
+
+class Test_RoundTrips(unittest.TestCase):
+    def setUp(self):
+        self.code = NameSpace(
+            structs=(
+                StructDef(
+                    name='Item',
+                    members=(
+                        MemberDef('b', BaseType.bytes),
+                        MemberDef('s', BaseType.utf8),
+                    ),
+                    discriminant=0xfacebeef,
+                ),
+            ),
+            name='test',
+        ).gen_dynamic_python()
+
+    def test_item(self):
+        orig = self.code.Item(b'\x00' * 4, 'Malkovich')
+        b = orig._enum_wrap(ts)
+        clone, = self.code.Test.read_many(memoryview(b))
+        self.assertEqual((ts, orig), clone)
+
+    def test_item(self):
+        bad_utf = b'\xc3\x28'
+        ts = 0
+
+        orig = self.code.Item(b'\xff', 'AA')
+
+        a = orig._enum_wrap(ts)
+        a = a[:-len(bad_utf)] + bad_utf
+
+        b = orig._enum_wrap(ts)
+
+        first, second = list(self.code.Test.read_many(memoryview(a + b)))
+        self.assertIsInstance(first, UnicodeDecodeError)
+        self.assertEqual(second, (ts, orig))

xpdt/templates/xpdt.pyt

@@ -31,6 +31,7 @@ from typing import (
     Optional as _O,
     Mapping as _M,
     Dict as _Dict,
+    Union as _U,
 )
 
 __all__ = (
@@ -264,14 +265,17 @@ class $$enumclass()$$:
                   _unp: _F[[bytes, int], _Tup[int, ...]] = _enum_unpack_from,
                   _hdr_len: int = _enum_size,
                   _clsmap: _M[int, _Typ[$$basetype()$$]] = structs,
-                  ) -> _G[_Tup[int, $$basetype()$$], None, None]:
+                  ) -> _G[_U[_Tup[int, $$basetype()$$], Exception], None, None]:
         tot_len = len(buf)
         off = 0
         while off < tot_len:
             rec_len, discr, ts = _unp(buf, off)
             off += _hdr_len
             t = _clsmap[discr]
-            yield ts, t._frombuf(buf, off)
+            try:
+                yield ts, t._frombuf(buf, off)
+            except (ValueError, UnicodeDecodeError) as e:
+                yield e
             off += rec_len
 
     @classmethod