Hello,

If the content of a text buffer is:

line 1<tag><br>line 2<br></tag>line 3

Where <br> is a "\n" char and tag has invisible=True, what is displayed is:

line1
line3

instead of:

line1line3

as I would expect (since both newlines should be invisible).

To reproduce, run this:

======================
import gtk

w = gtk.Window()
tv = gtk.TextView()
w.add(tv)
tb = tv.get_buffer()
tag = tb.create_tag('invisible')
tag.props.invisible = True

tb.insert(tb.get_start_iter(), "line 1\nline 2\nline 3")
start_hide = tb.get_iter_at_offset(6)
end_hide = tb.get_iter_at_offset(14)
tb.apply_tag(tag, start_hide, end_hide)

w.show_all()

gtk.main()
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