While testing the sequences for touching consonants that I have
included in a Wijesekera keymap being made by me in KMFL
(http://kmfl.sourceforge.net/), I detected a bug in BhashithaComplex
and BhashithaComplexSans fonts for Linux released by ICTA.
The code points sequence for any two consonants touching is: <CONS1>
200D 0DCA <CONS2> wherein CONS1 and CONS2 are the two consonants
which are to touch with al-lakuna hidden. The bug I observe is when
both are ස (dantaja sayanna).
You can see it in the attached screen shot file:
touch-cons-LibreWriter.png taken in Libre Writer. With the correct
sequence when either one of the Bhashita font is used the second
character changes to mayanna. Changing font to LKLUG shows it
correctly as ස but of course LKLUG lacks the level 3 ligature to hide
al-lakuna and also show touching correctly.
The other combinations I tried - (ම,ම) (ක,ක), (න,න) and (ස.ම) all
yield correct ligatures.
I also looked at the ligature for ස touching ම under fontforge -
attached file touch_sa_ma_liga-bhashita-fontforge.png . The sub-tables
and the components fields for the Ligature do not have any additional
data to cover the case of both consonant being ස. So why these
Bhashitha fonts yield this bug is beyond my level of know-how.