On Wed, 9 Nov 2016 00:00:01 +0100 Philippe Verdy <[email protected]> wrote:
> 2016-11-08 9:30 GMT+01:00 Richard Wordingham < > [email protected]>: > > > TUS Section 2.11 says, "If the combining characters can interact > > typographically—for example, U+0304 combining macron and U+0308 > > combining diaeresis — then the order of graphic display is > > determined by the order of coded characters (see Table 2-5). > > By default, the diacritics or other combining characters are > > positioned from the base character’s glyph outward". > The interpretation of "If the combining characters can interact > typographically" should be better read as "If the combining > characters have the same non-zero combining class or any one of them > has a zero combining class". The combining marks in question both have canonical combining class 0. > But now normalization is everywhere and causes the pairs using the > condition above to be freely reordered (or decomposed and recomposed, > meaning that the encoding order is NOT significant at all). I believe a renderer is permitted to treat canonically equivalent sequence differently so long as it does not believe it should treat them differently. However, that is irrelevant to this case. Richard.
