client-api: Add support for account locking

According to MSC3939.

crates/ruma-client-api/CHANGELOG.md

@@ -36,6 +36,7 @@ Improvements:
   - This is a breaking change, but only for users of `unstable-msc3575`
 - Add the `get_login_token` field to `Capabilities`, according to a
   clarification in the spec.
+- Add support for account locking, according to MSC3939.
 
 Bug fixes:
 

crates/ruma-client-api/src/error.rs

@@ -204,6 +204,9 @@ pub enum ErrorKind {
     #[cfg(feature = "unstable-msc3843")]
     Unactionable,
 
+    /// M_USER_LOCKED
+    UserLocked,
+
     #[doc(hidden)]
     _Custom { errcode: PrivOwnedStr, extra: Extra },
 }
@@ -280,6 +283,7 @@ impl AsRef<str> for ErrorKind {
             Self::WrongRoomKeysVersion { .. } => "M_WRONG_ROOM_KEYS_VERSION",
             #[cfg(feature = "unstable-msc3843")]
             Self::Unactionable => "M_UNACTIONABLE",
+            Self::UserLocked => "M_USER_LOCKED",
             Self::_Custom { errcode, .. } => &errcode.0,
         }
     }
@@ -927,4 +931,28 @@ mod tests {
             })
         );
     }
+
+    #[test]
+    fn serialize_user_locked() {
+        let error = Error::new(
+            http::StatusCode::UNAUTHORIZED,
+            ErrorBody::Standard {
+                kind: ErrorKind::UserLocked,
+                message: "This account has been locked".to_owned(),
+            },
+        );
+
+        let response = error.try_into_http_response::<Vec<u8>>().unwrap();
+
+        assert_eq!(response.status(), http::StatusCode::UNAUTHORIZED);
+        let json_body: JsonValue = from_json_slice(response.body()).unwrap();
+        assert_eq!(
+            json_body,
+            json!({
+                "errcode": "M_USER_LOCKED",
+                "error": "This account has been locked",
+                "soft_logout": true,
+            })
+        );
+    }
 }

crates/ruma-client-api/src/error/kind_serde.rs

@@ -252,6 +252,7 @@ impl<'de> Visitor<'de> for ErrorKindVisitor {
             },
             #[cfg(feature = "unstable-msc3843")]
             ErrCode::Unactionable => ErrorKind::Unactionable,
+            ErrCode::UserLocked => ErrorKind::UserLocked,
             ErrCode::_Custom(errcode) => ErrorKind::_Custom { errcode, extra },
         })
     }
@@ -310,6 +311,7 @@ enum ErrCode {
     WrongRoomKeysVersion,
     #[cfg(feature = "unstable-msc3843")]
     Unactionable,
+    UserLocked,
     _Custom(PrivOwnedStr),
 }
 
@@ -330,7 +332,7 @@ impl Serialize for ErrorKind {
         let mut st = serializer.serialize_map(None)?;
         st.serialize_entry("errcode", self.as_ref())?;
         match self {
-            Self::UnknownToken { soft_logout: true } => {
+            Self::UnknownToken { soft_logout: true } | Self::UserLocked => {
                 st.serialize_entry("soft_logout", &true)?;
             }
             Self::LimitExceeded { retry_after: Some(RetryAfter::Delay(duration)) } => {