[release-10.11] Restrict group_constrained to channels that support group sync (#36916)

Automatic Merge

server/public/model/channel.go

@@ -329,6 +329,10 @@ func (o *Channel) IsValid() *AppError {
 		}
 	}
 
+	if o.IsGroupConstrained() && !o.SupportsGroupSync() {
+		return NewAppError("Channel.IsValid", "model.channel.is_valid.group_constrained.app_error", nil, "id="+o.Id, http.StatusBadRequest)
+	}
+
 	return nil
 }
 
@@ -356,6 +360,11 @@ func (o *Channel) IsGroupOrDirect() bool {
 	return o.Type == ChannelTypeDirect || o.Type == ChannelTypeGroup
 }
 
+// SupportsGroupSync reports whether group_constrained is meaningful for the channel type.
+func (o *Channel) SupportsGroupSync() bool {
+	return o.Type == ChannelTypeOpen || o.Type == ChannelTypePrivate
+}
+
 func (o *Channel) IsOpen() bool {
 	return o.Type == ChannelTypeOpen
 }