Merge pull request #3989 from matrix-org/rav/better_stacktraces

Avoid reraise, to improve stacktraces

1 files changed, 13 insertions, 12 deletions

diff --git a/synapse/handlers/message.py b/synapse/handlers/message.py
index e484061cc0..4954b23a0d 100644
--- a/synapse/handlers/message.py
+++ b/synapse/handlers/message.py
@@ -14,9 +14,7 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 import logging
-import sys
 
-import six
 from six import iteritems, itervalues, string_types
 
 from canonicaljson import encode_canonical_json, json
@@ -624,6 +622,9 @@ class EventCreationHandler(object):
             event, context
         )
 
+        # reraise does not allow inlineCallbacks to preserve the stacktrace, so we
+        # hack around with a try/finally instead.
+        success = False
         try:
             # If we're a worker we need to hit out to the master.
             if self.config.worker_app:
@@ -636,6 +637,7 @@ class EventCreationHandler(object):
                     ratelimit=ratelimit,
                     extra_users=extra_users,
                 )
+                success = True
                 return
 
             yield self.persist_and_notify_client_event(
@@ -645,17 +647,16 @@ class EventCreationHandler(object):
                 ratelimit=ratelimit,
                 extra_users=extra_users,
             )
-        except:  # noqa: E722, as we reraise the exception this is fine.
-            # Ensure that we actually remove the entries in the push actions
-            # staging area, if we calculated them.
-            tp, value, tb = sys.exc_info()
-
-            run_in_background(
-                self.store.remove_push_actions_from_staging,
-                event.event_id,
-            )
 
-            six.reraise(tp, value, tb)
+            success = True
+        finally:
+            if not success:
+                # Ensure that we actually remove the entries in the push actions
+                # staging area, if we calculated them.
+                run_in_background(
+                    self.store.remove_push_actions_from_staging,
+                    event.event_id,
+                )
 
     @defer.inlineCallbacks
     def persist_and_notify_client_event(