GNOME Bugzilla – Bug 518084
Thai is not Virama language
Last modified: 2008-02-28 12:02:34 UTC
Caret positioning on Thai text wrongly skips THAI CHARACTER PHINTHU (U+0E3A). This is because the mark is treated as Virama, which is not true for Thai. To reproduce the bug, open gedit and paste the following text: ธมฺมํ Place caret like this: ธมฺมํ| Press <left-arrow>: ธ|มฺมํ Expected result: ธมฺ|มํ
Created attachment 105764 [details] [review] Patch removing Thai Phinthu from VIRAMA()
confirm reported behavior on libpango1.0-0 version 1.19.3-1ubuntu1
I was wondering, if any of the Unicode Technical Reports can be used to justify this change? TR#29 I mean... Couldn't find anything about viramas in it, but I didn't look very close.
TR#29 says nothing about Virama in grapheme cluster boundary. Only Hangul syllable is specially elaborated. However, one source to be referred to is probably The Unicode 5.0 standard itself. In Chapter 11 (Southeast Asian Scripts), pp. 376, where Thai transcription of Pali and Sanskrit is described: "...The Thai script is frequently used to write Pali and Sanskrit. When so used, consonant clusters are represented by the explicit use of U+0E3A THAI CHARACTER PHINTHU (virama) to mark the removal of the inherent vowel. *** There is no conjoining behavior, unlike in other Indic scripts. *** ..." The lack of conjuncts in Thai script eliminates the effect of the traditional Virama on glyphs shapes. The glyphs before and after it just stay intact. This makes PHINTU just another simple diacritic mark, which is supposed to be treated like other Thai combining characters.
Thanks. That's what I wanted to see :). 2008-02-28 Behdad Esfahbod <behdad@gnome.org> Bug 518084 – Thai is not Virama language Patch from Theppitak Karoonboonyanan * pango/break.c: Remove Thai Phinthu from VIRAMA()