We recently upgraded to 2019.1 and encountered a bug in our software caused by a change in behaviour since 2018.
In 2018.1 TextInput events are handled by the EditorView if the e.Text argument is not null or empty.
In 2019.1 TextInput events remain unhandled after processing and then fall through to the hosting control.
We managed to work around this by overriding event OnTextInput handler in a subclass of the Syntax editor and handling the event ourselves. But I wondered if this was an intentional change in behaviour?