incorrect description of UTF-8

[PeterCon]

Type of issue

Other (describe below)

Feedback

In this commit, the description of UTF-8 was changed to state that UTF-8 supports sequences of 1 to 6 bytes instead of 1 to 4 bytes. It supported this by referencing an annex of Unicode 1.1. However, that annex was not describing UTF-8 but rather a (now-obsolete) specification known as "UTF-1". Moreover, while early versions of Unicode did allow conformant implementations to interpret UTF-8 sequences of up to 6 bytes, Unicode changed the specification for UTF-8 in Unicode 3.1 (2001) to completely exclude sequences of more than four bytes. (That was done to eliminate a class of security vulnerabilities.) That commit from 2019 should not have been accepted.

See https://www.unicode.org/versions/Unicode16.0.0/core-spec/chapter-3/#G31703 for Unicode's specification of UTF-8

Page URL

https://learn.microsoft.com/en-us/windows/apps/design/globalizing/use-utf8-code-page

Content source URL

https://github.com/MicrosoftDocs/windows-dev-docs/blob/docs/hub/apps/design/globalizing/use-utf8-code-page.md

Author

@Karl-Bridge-Microsoft

Document Id

6fcd9265-4bfc-657a-9177-7c958f1b4b06