The "Default ignorable" property has nothing to do with rendering or being zero-width, it's just a matter of collation (comparing strings for similarity, for plain-text searches, or sorting them), it does not necesarily mean that the character is zero-width (that's a rendering property).
Characters that are "default ignorable" may still have an effect on cluster boundaries used when editing texts, if you count manually the number of zero-width characters (by pressng the left or right arrow fnction keys.) As long as the rendering is correct, editors may allow you to place insertion points between them. U+115F is the choseong filler (used when there's no leading consonnent to place before a medial vowel), U+1160 is the jungseong filler (used to replace a missing medial or final vowel). You're right when saying that there should be two clusters in <U+115F, U+1161>, <U+112B, U+1160> - The first one is a isolated vowel A, it should become spacing but U+115F is just used as an invisible holder for the vowel, - The second one is an isolated consonnant KAPYEOUNPIEUP, and the U+1160 filler will remain invisible except that it iis used here so that it explicitly terminates the cluster if it was followed by a leading consonnant or dirctly by a "defective" vovel. But the U+115F and U+1160 Hangul fillfers remain default ignorable in collation. And there's no bug about this. 2013/3/18 Konstantin Ritt <[email protected]>: > 2013/3/18 Konstantin Ritt <[email protected]>: >> The user reports Korean text rendering issue with any modern Hangul >> font when U+115F and U+1160 are handled like default_ignorable code >> points. >> [quote]With input string "U+115F U+1161 U+112B U+1160", we get three >> zero-width glyphs instead of two; this is wrong.[/quote] >> I did check some Hangul font and found that either U+115F or U+1160 >> zero-advances, not both. When handling them like default ignorable, >> the rendered text seems to lack some advancing. >> Since I know nothing about Korean typography, I'd like to ask here: >> what is the reason for U+115F and U+1160 to be default ignorables and >> shouldn't that be revised?
