Feedback on the proposal to change U+FFFD generation when decoding ill-formed UTF-8

Alastair Houghton via Unicode unicode at
Tue May 23 13:09:33 CDT 2017

> On 23 May 2017, at 18:45, Markus Scherer via Unicode <unicode at> wrote:
> On Tue, May 23, 2017 at 7:05 AM, Asmus Freytag via Unicode <unicode at> wrote:
>> So, if the proposal for Unicode really was more of a "feels right" and not a "deviate at your peril" situation (or necessary escape hatch), then we are better off not making a RECOMMEDATION that goes against collective practice.
> I think the standard is quite clear about this:
> Although a UTF-8 conversion process is required to never consume well-formed subsequences as part of its error handling for ill-formed subsequences, such a process is not otherwise constrained in how it deals with any ill-formed subsequence itself. An ill-formed subsequence consisting of more than one code unit could be treated as a single error or as multiple errors.

Agreed.  That paragraph is entirely clear.

Kind regards,



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