Brett Cannon said in the other thread:
this could lead to very odd data issues if you’re reading something in a different encoding that happens to be compatible enough with UTF-8
I know that ASCII-only UTF-{16,32}-{BE,LE} can be decoded as UTF-8, resulting in ASCII interspersed with null bytes. Any other examples of encodings which can accidentally be successfully decoded as UTF-8, leading to silent data corruption rather than a decoding error? Especially among the Windows code pages? Please share, I’m genuinely interested!
Also: PEP 538 mentions that enabling UTF-8 mode can lead to encoding inconsistencies between the Python core and locale-aware extensions. Can this mismatch have any negative impact on those using non-UTF-8 locales once UTF-8 mode becomes the default?