Here is a patch updating the French spelling dictionary and the thesaurus.
For LO 5.3 and master.
Steps to Reproduce:
User Profile Reset: No
User-Agent: Mozilla/5.0 (Windows NT 6.1; Win64; x64; rv:53.0) Gecko/20100101 Firefox/53.0
Created attachment 133004 [details]
[Update] French spelling dictionary and thesaurus
Thanks for your patch! I pushed it to master and libreoffice-5-3.
Thanks for your great work on this Olivier, and for pushing the patch Adolfo :) Sophie