This is equivalent to (gtk_text_iter_begins_tag() || gtk_text_iter_ends_tag()), i.e. it tells you whether a range with @tag applied to it begins or ends at @iter.
a #GtkTextTag, or %NULL
Return: whether @tag is toggled on or off at @iter
See Implementation
This is equivalent to (gtk_text_iter_begins_tag() || gtk_text_iter_ends_tag()), i.e. it tells you whether a range with @tag applied to it begins or ends at @iter.