Simplify exception handling in is_ascii. (#9985)

We can get away with just catching UnicodeError here.

    ⋮
    +-- ValueError
    |    +-- UnicodeError
    |         +-- UnicodeDecodeError
    |         +-- UnicodeEncodeError
    |         +-- UnicodeTranslateError
    ⋮

https://docs.python.org/3/library/exceptions.html#exception-hierarchy

Signed-off-by: Dan Callahan <danc@element.io>

1 files changed, 1 insertions, 3 deletions

diff --git a/synapse/util/stringutils.py b/synapse/util/stringutils.py

index 40cd51a8ca..f029432191 100644
--- a/synapse/util/stringutils.py
+++ b/synapse/util/stringutils.py
@@ -55,9 +55,7 @@ def random_string_with_symbols(length: int) -> str:
 def is_ascii(s: bytes) -> bool:
     try:
         s.decode("ascii").encode("ascii")
-    except UnicodeDecodeError:
-        return False
-    except UnicodeEncodeError:
+    except UnicodeError:
         return False
     return True