Is this a bug or a feature? Is it desired that sometimes log_params be easily human readable?

Its a historical thing.

Once upon a time, fields for log_params were separated by a newline. Then it got changed to being json blob (And possibly there's a couple php serialized blobs in there too, not sure). However not all log types got changed to the new format.

Anyone creating a new log type should use the json serialization. Old log types should be moved to use the the new json format for new entries. (And eventually when that is done, if someone is really board they could create a maintenance script to change old log entries.)

json? php serialized is the current format

(In reply to db from comment #3)

json? php serialized is the current format

Whoops, my mistake.

Also block log appears to use csv.

Suffice it to say, log_params is a bit of a mess.

Page protection events also insert into log_params unserialized content like this:

‎[edit=autoconfirmed] (indefinite)‎[move=autoconfirmed] (indefinite)

Following patches already exists:

• gerrit 151683 - Migrate merge log to new log system
• gerrit 151701 - Migrate import log to new log system
• gerrit 152003 - Migrate block log to new log system
• gerrit 152156 - Migrate protect log to new log system
• gerrit 152161 - Use new log system when create log entry for revision delete

So in the grand scheme of things, I'm a rather new MediaWiki contributor so I'm not too knowledgeable on the older log types but over Wikimania I wrote a maintenance script with help from various seasoned folks to do that does this task for an older format used by one of ShoutWiki's custom extensions as part of the script.

If someone were to generate a list of older log types that are not currently serialized and perhaps links/screenshots of real examples of the parameters in use it would be very helpful as different logs have different parameters etc.

Okay, when there should be a maintenance script to change old logs, than that is not a duplicate.

I see no point of changing the format of the old log rows, because MediaWiki can understand the old format and show old log records. It is just a problem when using the logging table direct on ToolLabs or the logging xml dump, which than also contains the old format, but I did not known if the serialized php is also deserialized for putting in the xml.