Reject boolean power levels (#14944)

* Better test for bad values in power levels events

The previous test only checked that Synapse didn't raise an exception,
but didn't check that we had correctly interpreted the value of the
dodgy power level.

It also conflated two things: bad room notification levels, and bad user
levels. There _is_ logic for converting the latter to integers, but we
should test it separately.

* Check we ignore types that don't convert to int

* Handle `None` values in `notifications.room`

* Changelog

* Also test that bad values are rejected by event auth

* Docstring

* linter scripttttttttt

* Test boolean values in PL content

* Reject boolean power levels

* Changelog

1 files changed, 3 insertions, 3 deletions

diff --git a/synapse/events/utils.py b/synapse/events/utils.py
index 52e4b467e8..ebf8c7ed83 100644
--- a/synapse/events/utils.py
+++ b/synapse/events/utils.py
@@ -648,10 +648,10 @@ def _copy_power_level_value_as_integer(
 ) -> None:
     """Set `power_levels[key]` to the integer represented by `old_value`.
 
-    :raises TypeError: if `old_value` is not an integer, nor a base-10 string
+    :raises TypeError: if `old_value` is neither an integer nor a base-10 string
         representation of an integer.
     """
-    if isinstance(old_value, int):
+    if type(old_value) is int:
         power_levels[key] = old_value
         return
 
@@ -679,7 +679,7 @@ def validate_canonicaljson(value: Any) -> None:
     * Floats
     * NaN, Infinity, -Infinity
     """
-    if isinstance(value, int):
+    if type(value) is int:
         if value < CANONICALJSON_MIN_INT or CANONICALJSON_MAX_INT < value:
             raise SynapseError(400, "JSON integer out of range", Codes.BAD_JSON)