Last modified: 2014-04-23 11:58:25 UTC
An API call to wbeditentity, that uses the existing claim guid, is able to change the property of the claim. See https://www.wikidata.org/w/index.php?title=Q6240488&diff=114789738&oldid=114788831 In the diff, the presentation assumes the property of the claim is the same before and after. However in the previous revision, there was a 'title' claim. In the modified revision, there is a 'birth name' claim. Either the API or the Diff logic is wrong.
It would seem the Diff logic is wrong :)
It should not be possible to change the property.
See https://bugzilla.wikimedia.org/show_bug.cgi?id=55911
Change 120537 had a related patch set uploaded by Daniel Kinzler: (bug 62425) Property of main snak must not change. https://gerrit.wikimedia.org/r/120537
note, it's also possible to add a snak with mismatching property data type and data value
Change 120537 merged by jenkins-bot: (bug 62425) Property of main Snak must not change https://gerrit.wikimedia.org/r/120537
(In reply to Aude from comment #5) > note, it's also possible to add a snak with mismatching property data type > and data value this will be solved by bug 62644