Websocket messages occasionally have null change_size values

[mahmoud]

Websocket messages will occasionally have null values for the change_size key in the JSON. This can be the result of a non-edit recent change entry, such as Special:Log/abuse, which actually doesn't have a size, but those entries actually don't have sizes. For real edits, this problem only seems to occur when it's a "Wikipedia-generated" message, such as "replaced content with '...'" or "Undid revision...".

For reference, an example IRC message:

[[Life sciences]] http://en.wikipedia.org/w/index.php?diff=558037670&oldid=555286077 * 41.133.165.179 * (�-2118�) [[WP:AES|←]]Replaced content with 'Science = Ashleigh.'

And the resulting JSON:

'{"is_anon": true, "page_title": "Life sciences", "url": "http://en.wikipedia.org/w/index.php?diff=558037670&oldid=555286077", "is_unpatrolled": false, "is_bot": false, "is_new": false, "is_minor": false, "summary": "(\\u0002-2118\\u0002) [[WP:AES|\\u2190]]Replaced content with \'Science = Ashleigh.\'", "flags": null, "user": "41.133.165.179", "ns": "Main", "change_size": null}'