Summary:
Calling navigator.replace(0, scene) has no effect.
This is because 0 is false in Javascript so when
this.state.updatingAllIndicesAtOrBeyond == 0
(meaning update all indices starting with 0)
The whole expression evaluates to 0, i.e. false -> therefore no update
happens.
Explicitly checking for not-equal to null (!= will convert undefined to null automatically) fixes the issue.
Closes https://github.com/facebook/react-native/pull/5155
Reviewed By: svcscm
Differential Revision: D2807397
Pulled By: nicklockwood
fb-gh-sync-id: 519a4ab35c86b0b608808b36593f5f8c2ecd1561
61025a9b33