Hello again! The minor version release with the updated HarfBuzz has corrected the earlier behavior regarding the half-form glyphs requested with ZWJs and XeTeX’s parsing of script tags, but appears to have introduced another Indic shaping regression into HarfBuzz.
In Bengali and Oriya (and some other Indic scripts, I think, but these’re what I’m familiar with) certain consonant-vowel combinations trigger a lookup for ligatures. Which ones are included differs from font to font, but good ones contain them, but Unicode describes a method for *not* selecting the ligated form as well. The chapter on Bengali in the Unicode standard describes how the behavior works. A given font can choose whether or not to use the ligated forms as the default for rendering. If the ligated form is the default, a ZWNJ can be inserted between the consonant and vowel to request the non-ligated form (e.g., C-ZWNJ-V). If the non-ligated form is the default (uncommon), a ZWJ can be inserted inbetween to request the ligated form. While it’s not mentioned in the Unicode or OpenType standards, the Oriya script contains these special consonant-vowel ligatures just like Bengali. While most fonts default to the ligated versions, it’s my understanding of the two specs that ZWJs should be able to be included anyway to explicitly request ligatures, even if it’s technically redundant. Testing with 0.9999.0 showed that that worked just fine with both Bengali and Oriya fonts I tested. 0.9999.1 seems to have broken this, and I assume it’s a problem in HarfBuzz again. I’ve linked a MWE below that demonstrates the bug. It uses Microsoft’s Shonar Bangla font again and INDOLIPI’s e-Oriya OT font, since it’s one of the only OpenType Oriya fonts I know of that contains CV ligatures. [Available here: http://www.aai.uni-hamburg.de/indtib/INDOLIPI/Indolipi.htm] Bengali text functions *correctly* for ligatures that’re of the form CV, but fails for those that’re CCV. Oriya CV ligatures now fail completely. [http://pastebin.com/SQWvcPnQ] (I’m guessing that like the other bug, this is likely better reported on the HarfBuzz list rather than XeTeX’s. I’d register for that list and bugtracker to report it there, but I don’t know how to use HarfBuzz’s testing tools to check shaping behavior outside of XeTeX. Any assistance would be greatly appreciated so I can help in reporting these sorts of not-XeTeX’s-fault bugs upstream in HarfBuzz.) -------------------------------------------------- Subscriptions, Archive, and List information, etc.: http://tug.org/mailman/listinfo/xetex
