Character entries of Dict widget are considered modified when their value is None
Contrary to usual Character widgets the widgets used in the Dictionary are considered modified if their value is None.
In fact what happens is that there is no validation of the value of the dict, so if some code set a char value to None. The widget will be considered modified while it wasn't in any way. This does not happen for usual fields.Char
because tryton will convert None to ""
during the read.
We should probably unify the behaviour which is the goal of the attached review.