TypeError is triggered when element being compared has a NULL title or Content

Module version(s) affected

Description

When a record is saved without a title or content, when viewing the RSS changes feed, a type error occurs.

Uncaught TypeError: SilverStripe\View\Parsers\HtmlDiff::compareHtml(): Argument #1 ($from) must be of type array|string, null given, called in /var/www/html/vendor/silverstripe/versionfeed/src/VersionFeed.php on line 110

How to reproduce

I first encountered the issue with Elemental, after saving an element without a title. But it should be the case for any page too (although it is less likely to save a page without title through the CMS). Easiest way to reproduce is to temper with database if possible, set a page record version title or content to NULL, then visit the page URL/changes.

Possible Solution

No response

Additional Context

No response

Validations

[X] Check that there isn't already an issue that reports the same bug
[X] Double check that your reproduction steps work in a fresh installation of silverstripe/installer (with any code examples you've provided)

PRs

https://github.com/silverstripe/silverstripe-versionfeed/pull/96

silverstripe / silverstripe-versionfeed