Memory leak if decompressed stream is not explicitly closed

[robsmith11]

I was iterating over thousands of bzip2 files with a function like this:

function read_first_line(filename)
    open(filename) do f
        f2 = CodecBzip2.Bzip2DecompressorStream(f)
        r = first(eachline(f2))
        # close(f2)
    end
end

The original form (with close(f2) commented out) would leak over 100 GB memory and begin swapping. Calling GC.gc() had no effect on the memory usage. But when using close(f2), the julia process memory usage remains under 1 GB.

So I'm guessing some memory isn't getting cleared up properly. I would expect that the f2 decompressed stream should be cleared from memory at some point after it goes out of scope, at least before the Julia process runs out of system memory or when GC.gc() is run.