The current check relies on the prototype which isn't robust enough.
Created attachment 282110 [details] Patch for review
Youenn, is the third set of tests actually valid to test this feature?
Comment on attachment 282110 [details] Patch for review r=me
(In reply to comment #2) > Youenn, is the third set of tests actually valid to test this feature? The test should probably be updated to use Object.setPrototypeOf.
(In reply to comment #3) > Comment on attachment 282110 [details] > Patch for review > > r=me I think this patch is good to go. I r+ed it. At the same time, it might be better to check again the third set of tests and maybe update the test. Hence why I removed the r+, especially since there was no r? at the beginning
Created attachment 282226 [details] Updated patch
Comment on attachment 282226 [details] Updated patch Thanks Youenn
Comment on attachment 282226 [details] Updated patch Clearing flags on attachment: 282226 Committed r202565: <http://trac.webkit.org/changeset/202565>
All reviewed patches have been landed. Closing bug.