Fix missing "promise kept" status for the last line in a file.

For the last line we shortcut out using MatchRegion, but previously
we did not set the promise status.

Fixes issue 2943.
(cherry picked from commit b626ba47d5243894bd7cd25d17cc15ff023007d9)
Update ChangeLog with fix for 2943
Fix "changes" promise not receiving status when file is missing.

Fixes issue 2820.
(cherry picked from commit 14facb9b97581ff756d2b94429770ed0113dae8a)
Update ChangeLog with fix for 2820