Check if a processed orphan is in the main chain and update its parent accordingly

[someone235]

This PR fixes the situation where a new block is first not considered in the main chain, but then after processing orphans that depend on it the block is now on the heaviest chain, but ProcessBlock still mistakenly returns that it's not in the main chain.

[jakesylvestre]

Looks good!

[jakesylvestre]

@jcvernaleo (as per #1530)

• low priority

[jakesylvestre]

@someone235 can you add a description here?

[someone235]

@someone235 can you add a description here?

I updated the description. I hope it's clear

[jakesylvestre]

Cool - will test this out tomorrow

[jakesylvestre]

Hey - one more thing. Looks like you'll have to rebase or force push so tests pass

[someone235]

Rebased

[coveralls]

Pull Request Test Coverage Report for Build 413871199

• 10 of 12 (83.33%) changed or added relevant lines in 1 file are covered.
• 17 unchanged lines in 2 files lost coverage.
• Overall coverage increased (+1.7%) to 53.375%

---

Changes Missing Coverage	Covered Lines	Changed/Added Lines	%
blockchain/process.go	10	12	83.33%

Files with Coverage Reduction	New Missed Lines	%
btcec/signature.go	6	91.64%
peer/peer.go	11	75.47%

Totals
Change from base Build 407350020:	1.7%
Covered Lines:	20830
Relevant Lines:	39026

---

💛 - Coveralls

[onyb]

Seems good from the look of it. I think it's also interesting to use fullblocktests and write a regression test since this PR touches consensus-critical code.

[someone235]

Seems good from the look of it. I think it's also interesting to use fullblocktests and write a regression test since this PR touches consensus-critical code.

TBH I probably won't have time for this anytime soon, so you can add the test if you want.