Problem description: Empty delimiter runtime error is observed when switching to "Test" tab in Regular expression configuration form, if an empty expression with expression type = "Character string not included" is configured in "Expressions" section.
Steps to reproduce:
- Navigate to Administration => General => Regular expressions and press "New regular expression" button
- In field "Expressions" set Expression type = "Character string included" and make sure field "Expression" is empty
- Switch to "Test" tab
Result: The following runtime error is observed:
Expected: no errors should be triggered.