I18Nsync overrides taxonomy terms of translated nodes with wrong language terms

I have translation activated for my nodes. PLUS i use multilingual taxonomies (not via Localize!).
I have terms like this

tid:20, language:en client
tid:21, language:de Kunde
...

PLUS i have I18NSync activated and enabled for the node taxonomies.

1. Now, I have an English node that has a German translation.
2. I edit the English node, attaching the term client... then i would expect to have the German term Kunde attached to the German translation...
3. ... but that's not the case. Instead the German translation gets the English term client attached.

I studied the module. The solution is to add a line in i18nsync_taxonomyfield(&$node, $source) to make sure that terms are available in the correct format. See the attached patch.