zulip: Reraise exceptions in do_api_query.

There are cases where the call to an endpoint may result in an
exception the traceback for which is converted into JSON and
returned to the caller. In the case of such an unsuccessful
response, we should just reraise the exception instead of parsing
the response as though it was successful.

zulip/zulip/__init__.py

@@ -681,10 +681,7 @@ def end_error_retry(succeeded: bool) -> None:
                     continue
                 else:
                     end_error_retry(False)
-                    return {
-                        "msg": f"Connection error:\n{traceback.format_exc()}",
-                        "result": "connection-error",
-                    }
+                    raise
             except requests.exceptions.ConnectionError:
                 if not self.has_connected:
                     # If we have never successfully connected to the server, don't
@@ -696,16 +693,10 @@ def end_error_retry(succeeded: bool) -> None:
                 if error_retry(""):
                     continue
                 end_error_retry(False)
-                return {
-                    "msg": f"Connection error:\n{traceback.format_exc()}",
-                    "result": "connection-error",
-                }
+                raise
             except Exception:
                 # We'll split this out into more cases as we encounter new bugs.
-                return {
-                    "msg": f"Unexpected error:\n{traceback.format_exc()}",
-                    "result": "unexpected-error",
-                }
+                raise
 
             try:
                 if requests_json_is_function:
@@ -782,16 +773,28 @@ def do_register() -> Tuple[str, int]:
             if queue_id is None:
                 (queue_id, last_event_id) = do_register()
 
-            res = self.get_events(queue_id=queue_id, last_event_id=last_event_id)
+            try:
+                res = self.get_events(queue_id=queue_id, last_event_id=last_event_id)
+            except (
+                requests.exceptions.Timeout,
+                requests.exceptions.SSLError,
+                requests.exceptions.ConnectionError,
+            ):
+                if self.verbose:
+                    print(f"Connection error fetching events:\n{traceback.format_exc()}")
+                # TODO: Make this use our backoff library
+                time.sleep(1)
+                continue
+            except Exception:
+                print(f"Unexpected error:\n{traceback.format_exc()}")
+                # TODO: Make this use our backoff library
+                time.sleep(1)
+                continue
+
             if "error" in res["result"]:
                 if res["result"] == "http-error":
                     if self.verbose:
                         print("HTTP error fetching events -- probably a server restart")
-                elif res["result"] == "connection-error":
-                    if self.verbose:
-                        print(
-                            "Connection error fetching events -- probably server is temporarily down?"
-                        )
                 else:
                     if self.verbose:
                         print("Server returned error:\n{}".format(res["msg"]))