zf != NULL
ZIPPacker::start_file
This check was removed because it introduces a bug which prevents ZIPPacker from actually adding any files, since it must be opened before adding any files (and therefore shouldn't be NULL at the start of `start_file`).
Co-authored-by: Marcelo Fernandez <marcelofg55@gmail.com> Co-authored-by: James Westman <flyingpimonster@gmail.commail> Co-authored-by: MisterMX <mbxd12@web.de> Signed-off-by: MisterMX <mbxd12@web.de>