On Fri, 26 May 2017 21:41:49 +0000 Shawn Steele via Unicode <unicode@unicode.org> wrote:
> I totally get the forward/backward scanning in sync without decoding > reasoning for some implementations, however I do not think that the > practices that benefit those should extend to other applications that > are happy with a different practice. > In either case, the bad characters are garbage, so neither approach > is "better" - except that one or the other may be more conducive to > the requirements of the particular API/application. There's a potential issue with input methods that indirectly edit the backing store. For example, GTK input methods (e.g. function gtk_im_context_delete_surrounding()) can delete an amount of text specified in characters, not storage units. (Deletion by storage units is not available in this interface.) This might cause utter confusion or worse if the backing store starts out corrupt. A corrupt backing store is normally manually correctable if most of the text is ASCII. Richard.