Returns TRUE if tag is toggled off at exactly this point. If tag
is NULL, returns TRUE if any tag is toggled off at this point. Note
that the gtk_text_iter_ends_tag() returns TRUE if iter is the
end of the tagged range;
gtk_text_iter_has_tag() tells you whether an iterator is
within a tagged range.
Returns TRUE if tag is toggled off at exactly this point. If tag is NULL, returns TRUE if any tag is toggled off at this point. Note that the gtk_text_iter_ends_tag() returns TRUE if iter is the end of the tagged range; gtk_text_iter_has_tag() tells you whether an iterator is within a tagged range.