The excerpt field in the database is constrained to 1000 chars in length. To support this constraint we added a restriction that the topic_excerpt_maxlength setting must be between 0 and 999.
Unfortunately, sometimes it doesn’t work because:
- topic_excerpt_maxlength restricts the length of a visible to user excerpt. But we HTML-escape text before saving. If an excerpt contains & it’ll be &. One character for the user but 5 characters to save to the database. So if topic_excerpt_maxlength is set to 999 it’s not so hard to have an excerpt of for example 1003 characters in length and run into this issue.
- It’s possible to define a custom excerpt for a topic. Such excerpts bypass check for a length. So if the user defines a too long custom excerpt he will run into this issue.
Removing the constraint on the database level solves the problem. But we still need the constraint for topic_excerpt_maxlength on the setting page, because too long excerpts would make UI wonky.