Fix special ansi sequences not ignored and producing wrong colors

[Delgan]

Hi.

This change is intended to fix #217.

On Linux, special coloration sequences may be initialized with 38 (foreground) and 48 (bakground) ansi codes. 8-bit looks like \x1b[38;5;46m and 24-bit looks like \x1b[38;2;120;33;255m. These colors are not supported by Windows terminal as far as I know (maybe PowerShell console supports it?), so they should be ignored by colorama, as it is the case for others special styles.

Notes about my implementation:

• I tried to optimize for the main use case which happens when there is no such special sequence. The overhead is just one check against skip truthy value most of the time.
• There is some edge cases like \x1b[38;0;31m or \x1b[38;48;5;46m. According to my observations on Linux, if the ansi code folowing 38 is not 2 nor 5, the sequence should be ignored (but another one can start immediatly).

Feel free to suggest improvements. 👍

[pfmoore]

hese colors are not supported by Windows terminal as far as I know

Recent versions of the Windows 10 terminal do support them

[tartley]

Hey. FYI, Yesterday I created a PR to test releases before we push them to PyPI. When that is merged, I'll be more confident about resuming merges and releases. I'll try to look at this PR soon. Thank you for creating it!

[tartley]

Apologies for being AWOL for years, but I'm rounding up PRs that should get merged.

This sounds AMAZING, and I'd like to merge it. Huge thanks! But I can't merge it without corresponding tests (How will future developers know if their changes break your code?)

[Delgan]

Hey @tartley, I just updated the PR by adding unit tests (and slightly modifying the implementation to make it more readable).

Please let me know what you think of it!