Ma Lin <malin...@163.com> added the comment:
I investigated this problem. Here is the toggle conditions: - The format is FORMAT_ALONE, this is the legacy .lzma container format. - The file's header recorded "Uncompressed Size". - The file doesn't have "End of Payload Marker" or "End of Stream Marker". Otherwise, liblzma's internal state doesn't hold any bytes that can be output. Good news is: - lzma module's default compressing format is FORMAT_XZ, not FORMAT_ALONE. - Even FORMAT_ALONE files generated by lzma module (underlying xz library), always have "End of Payload Marker". - Maybe FORMAT_ALONE format is being outdated in the world. Attached file test_bad_files.py, test `DecompressReader.read(size=-1)` function [1] with different max_length values (from -1 to 1000, exclude 0), can ensure that the needs_input mechanism works properly. Usage: modify `DIR` variable to bad files' folder. [1] https://github.com/python/cpython/blob/v3.8.0b1/Lib/_compression.py#L72-L111 ---------- Added file: https://bugs.python.org/file48425/test_bad_files.py _______________________________________ Python tracker <rep...@bugs.python.org> <https://bugs.python.org/issue21872> _______________________________________ _______________________________________________ Python-bugs-list mailing list Unsubscribe: https://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com
