Slightly simplify some BlockParser logic

[chirhonul]

Also add TODO about concern in validating block header vs just
block height.

[ripcurlx]

utACK

[ManfredKarrer]

Can you add the check for the blockHash as well?

[ManfredKarrer]

Yes, true.

[chirhonul]

That seems beyond the scope of the current PR (which is a refactor with no functional changes), which is why I added it as a TODO here. I'd be happy to address it in a follow-up PR.

[ManfredKarrer]

Ok.

[chirhonul]

Thanks for the review!

@ManfredKarrer: I'd prefer to change the functionality of isBlockAlreadyAdded() to make it more robust in a follow-up PR (see comment inline). Please take another look and see if you agree that we can merge this (once current release is out) as-is.

Edit: I forgot to mention that I believe that the failing CI build is unrelated to this change.. the error is:

[ ... ]
:compileJava FAILED
FAILURE: Build failed with an exception.
* What went wrong:
Could not resolve all files for configuration ':compileClasspath'.
> Could not find network.bisq:bisq-p2p:-SNAPSHOT.
[ ... ]
BUILD FAILED in 19s
1 actionable task: 1 executed
The command "eval ./gradlew assemble " failed. Retrying, 2 of 3.

I would rerun the Travis job, but I seem to lack the permissions to do so.

[chirhonul]

I've made the changes mentioned as a TODO in a branch based on this changeset:

• https://github.com/chirhonul/bisq-core/compare/1808-block-parse-tweaks...chirhonul:1808-check-blockhash?expand=1

I will open the second PR when this one has been merged.

[ManfredKarrer]

utACK