Incorrect line with "non-boolean (Int64) used in boolean context" error

[nalimilan]

With the function below I made a mistake and got a very explicit error. Only the line was clearly incorrect: the problem is actually subset[i] || continue at line 38.

function test(x::AbstractVector...;
                    subset::Union(Nothing, AbstractVector{Int}, AbstractVector{Bool}, BitVector) = nothing,
                    weights::Union(Nothing, AbstractVector{Number}) = nothing)
    n = length(x)
    l = map(length, x)
    vtypes = map(eltype, x)

    for i in 1:n
        if l[1] != l[i]
            error("arguments are not of the same length: $l")
        end
    end

    if (isa(subset, AbstractVector{Bool}) || isa(subset, BitVector)) && length(subset) != l[1]
        error("'subset' (length $(length(subset))) must be of the same length as vectors (length $(l[1])) when it is boolean")
    end

    if weights != nothing && length(weights) != l[1]
        error("'weights' (length $(length(weights))) must be of the same length as vectors (length $(l[1]))")
    end

    d = cell(n)

    if weights == nothing
        counts = Array(Int, 0)
    else
        counts = Array(eltype(weights), 0)
    end

    a = Array(Int, (0, 0))
    el = cell(n)

    if subset == nothing
        subset = 1:l[1]
    end

    for i in subset
        subset[i] || continue

        for j in 1:n
            pos = findfirst(a, x[j][i])
            if pos == 0
                d = push!(d, x[j][i])
                a = cat(j, a, zeros(Int, ntuple(n - 1, k -> k >= j ? k : k + 1)))
                pos = length(d)
            end

            @inbounds el[j] = pos
        end

        @inbounds a[el...] += 1
    end
end

julia> test([1:10]);
ERROR: type: non-boolean (Int64) used in boolean context
 in test at none:9

I've tried making a shorter example, but the bug vanishes when removing apparently unrelated code. For example, this version prints the correct line number:

function test2(x::AbstractVector...;
                    subset::Union(Nothing, AbstractVector{Int}, AbstractVector{Bool}, BitVector) = nothing,
                    weights::Union(Nothing, AbstractVector{Number}) = nothing)
    n = length(x)
    l = map(length, x)
    vtypes = map(eltype, x)

    d = cell(n)

    if weights == nothing
        counts = Array(Int, 0)
    else
        counts = Array(eltype(weights), 0)
    end

    a = Array(Int, (0, 0))
    el = cell(n)

    if subset == nothing
        subset = 1:l[1]
    end

    for i in subset
        subset[i] || continue

        for j in 1:n
            pos = findfirst(a, x[j][i])
            if pos == 0
                d = push!(d, x[j][i])
                a = cat(j, a, zeros(Int, ntuple(n - 1, k -> k >= j ? k : k + 1)))
                pos = length(d)
            end

            @inbounds el[j] = pos
        end

        @inbounds a[el...] += 1
    end
end

julia> test2(x)
ERROR: type: non-boolean (Int64) used in boolean context
 in test2 at none:23

For the record, is it useful to make such reports about line numbers, or is there a well-known issue about that?

EDIT: I did not paste the second function correctly.