Fix go vet failures

[misha-ridge]

No description provided.

[liamsi]

Thanks for your patience @misha-tectonic.

LGTM. I ran go vet a while ago and was wondering about the (commented) unreachable code too. It would be good to know what was the intention (if any).

[liamsi]

Just out of curiosity: which version of golang / go vet did you use? I do rememeber that go vet complained about these lines: https://github.com/tendermint/iavl/pull/95/files#diff-3f1ad41879763caf285707f64678af17L74

But it disappeared with upgrading golang (to 1.10.3 on darwin).

[misha-ridge]

Go 1.11beta2, beta3, rc1.

go vet test modules recursively, and go test runs go vet in 1.11, so any module that explicitly or implicitly includes iavl fails in the testsuite.

[liamsi]

Thanks!

[liamsi]

Interestingly, only c917ed2 seems necessary to make go vet happy:

go1.11rc1 test
# github.com/tendermint/iavl
./proof_range.go:368:6: lastDepth declared but not used
vet: typecheck failures
FAIL    github.com/tendermint/iavl [build failed]

After applying c917ed2 this passes.
In any case the unreachable code doesn't make sense. If there is an overflow append will panic and the second return is still unreachable.

[misha-ridge]

go test runs a subset of go vet tests. Running go vet standalone will emit the error about unreachable statement.

[liamsi]

I also ran go1.11rc1 vet and it only complained about:

go1.11rc1 vet
# github.com/tendermint/iavl
./proof_range.go:368:6: lastDepth declared but not used
vet: typecheck failures

I was surprised about this too. I do remember vet complaining about the unreachable statement (a while ago though).

[misha-ridge]

Oh, I see. go vet stops early: once you remove unused variables it starts complaining about unreachable code:

% git describe --tags
v0.9.2-1-gc917ed2
% go vet
# github.com/tendermint/iavl
./util.go:75: unreachable code