if we have rainbow flag emoji (🏳️‍🌈)
we can use mouse/keyboard to move cursor inside it because we break it into two clusters, we break on 1F308,
This is wrong as we should treat emoji as a single cluster (based on rules mentioned in Unicode segmentation standard “Do not break within emoji modifier sequences or emoji ZWJ sequences” (https://unicode.org/reports/tr29/#GB11 )).
this issue happens because we don’t give 1F308 its correct grapheme break property value, I think this is a bug in the unibreak library as this Unicode 1F308 should have word break class value equals to Glue_After_ZWJ (based on https://www.unicode.org/reports/tr29/tr29-31.html#Glue_After_Zwj_WB and http://unicode.org/Public/emoji/5.0/emoji-zwj-sequences.txt) which will not make it break and we will get a single cluster.
I noticed that the current unibreak lib used in EFL seems to implement Unicode 9 (latest is Unicode 13) which uses obsolete and unused grapheme break property, such as E_Modifier & Glue_After_ZWJ, so if a new emoji introduced (rainbow flag was introduced after Unicode 9) and based on Unicode 9 it should use property E_Modifier or Glue_After_ZWJ we will have issue with it.
So I have updated unibreak lib using latest released version of unibreak (4.2) which implement Unicode 12.
I needed to remove BREAK_AFTER(i) to pass the tests in D1140 as spaces do not break on latest update (also related to T995).