Hi,

I've noticed that there is a bug when blocking IP addresses and IP address range across multiple versions of MediaWiki. None of the Wikimedia Foundation projects seem to be having this issue. However, the Referata Wiki Farm (which runs MediaWiki version 1.25 globally), and thetestwiki.org (which runs the newest development version 1.29), have a bug where if you block an IP address as anonymous only, and then change the block to a hardblock, or vise versa, the software records it as a completely new block, not just a change in block settings. This means that the block list contains two different blocks for the same target with different parameters, and potentially even different expiry times. This issue does not occur for changing email/talk page access for either accounts or IP's. To cleary demonstrate this, I'll give this scenario:

• An administrator by the name of WikiAdminUser blocks IP address 12.34.56.78 anonymous only for 2 weeks.

• Either the same admin or another admin then modifies the block to be a hardblock and extends it to 1 month duration due to logged-in sock puppet abuse.

• The software seems to be recording it as a brand-new block, which means that there are now two separate blocks for 12.34.56.78 defined in the block list, with different parameters and expiry times.

• The IP address now has to be unblocked twice in order to clear the duplicate block, and then reblocked for one month as a hardblock

This problem seems to be occurring on many MediaWiki sites except WMF - with versions ranging from 1.25 to 1.28 to the master development 1.29