Fix UnicodeDecodeError when postgres is not configured in english (#4253)

This is a bit of a half-assed effort at fixing https://github.com/matrix-org/synapse/issues/4252. Fundamentally the right answer is to drop support for Python 2.
pull/4260/head
Richard van der Hoff 2018-12-04 11:55:52 +01:00 committed by GitHub
parent f144c0a210
commit ecc23188f4
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3 changed files with 47 additions and 8 deletions

1
changelog.d/4253.bugfix Normal file
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@ -0,0 +1 @@
Fix UnicodeDecodeError when postgres is configured to give non-English errors

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@ -29,6 +29,7 @@ from synapse.api.errors import StoreError
from synapse.storage.engines import PostgresEngine
from synapse.util.caches.descriptors import Cache
from synapse.util.logcontext import LoggingContext, PreserveLoggingContext
from synapse.util.stringutils import exception_to_unicode
logger = logging.getLogger(__name__)
@ -249,32 +250,32 @@ class SQLBaseStore(object):
except self.database_engine.module.OperationalError as e:
# This can happen if the database disappears mid
# transaction.
logger.warn(
logger.warning(
"[TXN OPERROR] {%s} %s %d/%d",
name, e, i, N
name, exception_to_unicode(e), i, N
)
if i < N:
i += 1
try:
conn.rollback()
except self.database_engine.module.Error as e1:
logger.warn(
logger.warning(
"[TXN EROLL] {%s} %s",
name, e1,
name, exception_to_unicode(e1),
)
continue
raise
except self.database_engine.module.DatabaseError as e:
if self.database_engine.is_deadlock(e):
logger.warn("[TXN DEADLOCK] {%s} %d/%d", name, i, N)
logger.warning("[TXN DEADLOCK] {%s} %d/%d", name, i, N)
if i < N:
i += 1
try:
conn.rollback()
except self.database_engine.module.Error as e1:
logger.warn(
logger.warning(
"[TXN EROLL] {%s} %s",
name, e1,
name, exception_to_unicode(e1),
)
continue
raise

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@ -16,7 +16,8 @@
import random
import string
from six import PY3
import six
from six import PY2, PY3
from six.moves import range
_string_with_symbols = (
@ -71,3 +72,39 @@ def to_ascii(s):
return s.encode("ascii")
except UnicodeEncodeError:
return s
def exception_to_unicode(e):
"""Helper function to extract the text of an exception as a unicode string
Args:
e (Exception): exception to be stringified
Returns:
unicode
"""
# urgh, this is a mess. The basic problem here is that psycopg2 constructs its
# exceptions with PyErr_SetString, with a (possibly non-ascii) argument. str() will
# then produce the raw byte sequence. Under Python 2, this will then cause another
# error if it gets mixed with a `unicode` object, as per
# https://github.com/matrix-org/synapse/issues/4252
# First of all, if we're under python3, everything is fine because it will sort this
# nonsense out for us.
if not PY2:
return str(e)
# otherwise let's have a stab at decoding the exception message. We'll circumvent
# Exception.__str__(), which would explode if someone raised Exception(u'non-ascii')
# and instead look at what is in the args member.
if len(e.args) == 0:
return u""
elif len(e.args) > 1:
return six.text_type(repr(e.args))
msg = e.args[0]
if isinstance(msg, bytes):
return msg.decode('utf-8', errors='replace')
else:
return msg