google/traceur-compiler — pull request #1449 by pselden (2014-10-28 15:22:33+00:00)
Title: Allow undefined/null as source for Object.assign. Fixes gh-1448

Object.assign should accept null/undefined as source and not error. As per https://esdiscuss.org/topic/july-24-2012-tc39-meeting-notes#revisit-object-assign-

Fixes #1448

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