[Bug]: lzma_str_to_filters() has confusing behavior with LZMA1 and flags

[Jia Tan]

Describe the bug

Not necessarily a bug, but the behavior is confusing. lzma_str_to_filters() is successful with the filter string "lzma1" when LZMA_STR_ALL_FILTERS flag is used, as expected. However, lzma_str_to_filters() fails with "lzma1" when LZMA_STR_NO_VALIDATION. This is confusing because the "validation" is too vague. Checking if a filter can be used with the .xz format is technically validation. So, either the code should change or the documentation should be updated to clarify this.

Version

5.4.1

Operating System

Ubuntu

Relevant log output

No response

[Jia Tan]

Created two PRs for this, but only one should be used. The better choice is probably #25, but I wanted to show both solutions to see which one we like better.