<html> <head> <meta content="text/html; charset=UTF-8" http-equiv="Content-Type"> </head> <body bgcolor="#FFFFFF" text="#000000"> Greetings, On 12-04-17 04:47 PM, Khaled Hosny wrote: <blockquote cite="mid:20120417224708.GA31487@khaled-laptop" type="cite"> <blockquote type="cite" style="color: #000000;"> <pre wrap="">I don't know about Thai, but the handling of "invalid" Arabic combining > marks in Uniscribe is completely brain dead and a real PITA and I'd > really like not to see HarfBuzz going there, a shaping engine is not a > spell checker and should not enforce any input pattern. > > <a moz-do-not-send="true" class="moz-txt-link-freetext" href="http://www.microsoft.com/typography/OpenType%20Dev/arabic/shaping.mspx#invalid">http://www.microsoft.com/typography/OpenType%20Dev/arabic/shaping.mspx#invalid</a> </pre> </blockquote> <pre wrap="">Incidentally, I came across this Typophile post, which is one example of why this "invalid" mark handling is not really a good idea: <a moz-do-not-send="true" class="moz-txt-link-freetext" href="http://typophile.com/node/92130">http://typophile.com/node/92130</a> </pre> </blockquote> I encountered a similar issue in Bengali script. In a minority language, someone needed to have U+0985 BENGALI LETTER A and U+09D7 BENGALI AU LENGTH MARK in sequence. XeTeX (with ICU rendering I believe) had a dotted circle in the output between these two characters. Later versions of Uniscribe did not produce the dotted circle. I would hope that HarfBuzz would also not display a dotted circle in this case. Cheers, Bobby <div class="moz-signature">-- Bobby de Vos <a class="moz-txt-link-abbreviated" href="mailto:devos.bobby@gmail.com">devos.bobby@gmail.com</a> </div> </body> </html>