core: forkchoice.go more readable code

[setunapo]

no logic change

[holiman]

Myeah, I can verify that your change is ok (does what it says). However, if we're clarifying things, perhaps this would be an improvement too?

	// If the total difficulty is higher than our known, add it to the canonical chain
	if diff := externTd.Cmp(localTD); diff > 0 {
		return true, nil
	} else if diff < 0 {
		return false, nil
	}
	// Local and external difficulty is identical.
	// Second clause in the if statement reduces the vulnerability to selfish mining.
	// Please refer to http://www.cs.cornell.edu/~ie53/publications/btcProcFC.pdf
	externNum, localNum := extern.Number.Uint64(), current.Number.Uint64()
	if externNum < localNum {
		reorg = true
	} else if externNum == localNum {
		var currentPreserve, externPreserve bool
		if f.preserve != nil {
			currentPreserve, externPreserve = f.preserve(current), f.preserve(extern)
		}
		reorg = !currentPreserve && (externPreserve || f.rand.Float64() < 0.5)
	}
	return reorg, nil

OTOH, not sure it's worth messing with this code -- in a post-merge world, the difficulty is not all that important any more.

[brilliant-lx]

Myeah, I can verify that your change is ok (does what it says). However, if we're clarifying things, perhaps this would be an improvement too?

	// If the total difficulty is higher than our known, add it to the canonical chain
	if diff := externTd.Cmp(localTD); diff > 0 {
		return true, nil
	} else if diff < 0 {
		return false, nil
	}
	// Local and external difficulty is identical.
	// Second clause in the if statement reduces the vulnerability to selfish mining.
	// Please refer to http://www.cs.cornell.edu/~ie53/publications/btcProcFC.pdf
	externNum, localNum := extern.Number.Uint64(), current.Number.Uint64()
	if externNum < localNum {
		reorg = true
	} else if externNum == localNum {
		var currentPreserve, externPreserve bool
		if f.preserve != nil {
			currentPreserve, externPreserve = f.preserve(current), f.preserve(extern)
		}
		reorg = !currentPreserve && (externPreserve || f.rand.Float64() < 0.5)
	}
	return reorg, nil

OTOH, not sure it's worth messing with this code -- in a post-merge world, the difficulty is not all that important any more.

Yea, your post if fine, making it much clearer, I will update.
After merge, difficulty is still important, it represents inturn & offturn.
It always necessary to make code clear, for easy maintenance, imo.
And there are many code in Geth could be improved to make it more understandable.

[holiman]

Thanks!