gh-132983: Don't allow trailer data in ZstdFile (#133736)

Author: Rogdham

Lib/compression/zstd/_zstdfile.py

@@ -89,7 +89,6 @@ def __init__(self, file, /, mode="r", *,
             raw = _streams.DecompressReader(
                 self._fp,
                 ZstdDecompressor,
-                trailing_error=ZstdError,
                 zstd_dict=zstd_dict,
                 options=options,
             )

Lib/test/test_zstd.py

@@ -1682,10 +1682,10 @@ def test_read_incomplete(self):
 
         # Trailing data isn't a valid compressed stream
         with ZstdFile(io.BytesIO(self.FRAME_42 + b'12345')) as f:
-            self.assertEqual(f.read(), self.DECOMPRESSED_42)
+            self.assertRaises(ZstdError, f.read)
 
         with ZstdFile(io.BytesIO(SKIPPABLE_FRAME + b'12345')) as f:
-            self.assertEqual(f.read(), b'')
+            self.assertRaises(ZstdError, f.read)
 
     def test_read_truncated(self):
         # Drop stream epilogue: 4 bytes checksum