Parallell.PutValue fails if one router fails but all other succeed

[ajnavarro]

We can see here:

go-libp2p-routing-helpers/parallel.go

Lines 329 to 331 in 506670d

	// PutValue puts the given key to all sub-routers in parallel. It succeeds as
	// long as putting to at least one sub-router succeeds, but it waits for all
	// puts to terminate.

that the Parallell.PutValue only fails if none of the routers were able to set the value.

But the logic is wrong here:

go-libp2p-routing-helpers/parallel.go

Lines 133 to 161 in 506670d

	var (
	errs []error
	success bool
	)
	for _, err := range results {
	switch err {
	case nil:
	// at least one router supports this.
	success = true
	case routing.ErrNotSupported:
	default:
	errs = append(errs, err)
	}
	}
	switch len(errs) {
	case 0:
	if success {
	// No errors and at least one router succeeded.
	return nil
	}
	// No routers supported this operation.
	return routing.ErrNotSupported
	case 1:
	return errs[0]
	default:
	return &multierror.Error{Errors: errs}
	}
	}

success is only checked if there are no errors, making PutValue fails even if just one router fails.