Port #12027, #11980 and #11932 to master#12037

Merged

zhengbli merged 1 commit intomicrosoft:masterfrom zhengbli:portOverwriteEmittingFix

Nov 4, 2016

Commits on Nov 3, 2016

Port microsoft#12027 , microsoft#11980 and microsoft#11932 to master
zhengbli
committed