Previous implementation was just rewriting content on each call to writeBytes() making this stream unusable. Improved and refactored corresponding Java unittest, now it check given above behavior and reacts on failures instead just writing mesages to stdout. Change-Id: Ib56baf07d8767b246a9d75cd5d639a2c2c0e7a5d Reviewed-on: https://gerrit.libreoffice.org/79840 Tested-by: Jenkins Reviewed-by: Noel Grandin <noel.grandin@collabora.co.uk>