BUG#30089671: Fix decoding VARBINARY columns when using a prepared cursor

nmariz · nmariz · commit f798837a6bde · 2022-10-13T09:21:33.000+01:00
When fetching results from a prepared cursor using the pure Python
implementation, it may fail if the VARBINARY column contains bytes
that cannot be decoded.

With this patch, bytes are returned if cannot be decoded.

Thank you for the contribution.

Change-Id: I1655daab3a320dbbde9942acca4fb06e64288bcf
diff --git a/CHANGES.txt b/CHANGES.txt
@@ -14,6 +14,7 @@ v8.0.32
 - WL#15348: Support MIT Kerberos library on Windows
 - WL#15036: Support for type hints
 - BUG#34556157: Kerberos authorization fails when using SSPI as security interface
+- BUG#30089671: Fix decoding VARBINARY columns when using a prepared cursor
 
 v8.0.31
 =======
diff --git a/lib/mysql/connector/protocol.py b/lib/mysql/connector/protocol.py
@@ -641,7 +641,10 @@ def _parse_binary_values(
                 values.append(value)
             else:
                 (packet, value) = utils.read_lc_string(packet)
-                values.append(value.decode(charset))
+                try:
+                    values.append(value.decode(charset))
+                except UnicodeDecodeError:
+                    values.append(value)
 
         return tuple(values)
 
diff --git a/tests/test_protocol.py b/tests/test_protocol.py
@@ -464,13 +464,17 @@ def test__parse_binary_values(self):
             ("aDateTime", 12, None, None, None, None, 1, 128),
             ("aTime", 11, None, None, None, None, 1, 128),
             ("aNull", 6, None, None, None, None, 1, 128),
+            ("aBlob", 252, None, None, None, None, 1, 144),
+            ("aVarBinary", 253, None, None, None, None, 1, 128),
         ]
 
         packet = bytearray(
             b"\x00\x01\x03\x61\x62\x63\x04\x33\x2e\x31\x34\x08"
             b"\x2d\x33\x2e\x31\x34\x31\x35\x39\x04\xd3\x07"
             b"\x01\x1f\x07\xb9\x07\x06\x0e\x15\x21\x0e\x0c"
             b"\x00\x0a\x00\x00\x00\x10\x0f\x1e\x70\x82\x03\x00"
+            b"\x05\xaa\xbb\xcc\xdd\xff"
+            b"\x05\xaa\xbb\xcc\xdd\xff"
         )
 
         # float/double are returned as DECIMAL by MySQL
@@ -482,6 +486,8 @@ def test__parse_binary_values(self):
             datetime.datetime(1977, 6, 14, 21, 33, 14),
             datetime.timedelta(10, 58530, 230000),
             None,
+            bytearray(b"\xaa\xbb\xcc\xdd\xff"),
+            bytearray(b"\xaa\xbb\xcc\xdd\xff"),
         )
         res = self._protocol._parse_binary_values(fields, packet)
         self.assertEqual(exp, res)
