Please describe the problem:
the Lingala word mɔ́to is not displayed properly with all the pango based
applications I have tested.
The same problem occurs with many IPA characters and diacritics

Steps to reproduce:
1. start any application using pango, e.g. gedit, and open gucharmap
2. copy any one of the combining diacritical marks after any character, e.g.  ́
U+0301 and then ɔ U+0251, ɛ U+025B or even try a.
3. see in gucharmap and paste to gedit



Actual results:
The diacritic mark is offset, i.e. not right on top of the wanted character, eg.
the combining grave on the latin small alpha áɑa

Expected results:
The diacritic should be on top of the wanted character.

Does this happen every time?
This happens everytime. Some fonts seem to do better but there is still
consistently an offset.

Other information:
Adding more than one diacritic mixes them instead of superposing them.
Adding a chacter before or after makes the diacritic jump from one to the next
sometimes.