Comment 1 for bug 1597811

https://bugzilla.redhat.com/show_bug.cgi?id=1411912

Description of problem:
Initial configuration, with three example notes
* Archive
* MyNote
* Done

Attempted action 1: move a note from top level into another note.
Result: The note got duplicated in the other note, as follows:
* Archive
 * MyNote
 * MyNote
* Done

Attempted action 2: Move the note to the other top-level note, so that the
intended result would be as follows:
* Archive
* Done
 * MyNote

Actual result was: a crash "Zim quit unexpectedly".

Version-Release number of selected component:
Zim-0.65-2.fc24

Additional info:
reporter: libreport-2.7.2
cmdline: /usr/bin/python /usr/bin/zim --ipc-server-main /tmp/zim-mikael/zim-server-socket 30
executable: /usr/bin/zim
kernel: 4.8.15-200.fc24.x86_64
pkg_fingerprint: 73BD E983 81B4 6521
pkg_vendor: Fedora Project
runlevel: N 5
type: Python
uid: 1000

Truncated backtrace:
pageindex.py:369:get_indexpath:AttributeError: 'NoneType' object has no attribute 'indexpath'

Traceback (most recent call last):
  File "/usr/lib/python2.7/site-packages/zim/gui/pageindex.py", line 547, in do_row_activated
    path = model.get_indexpath(iter)
  File "/usr/lib/python2.7/site-packages/zim/plugins/tags.py", line 778, in get_indexpath
    return model.get_indexpath(childiter)
  File "/usr/lib/python2.7/site-packages/zim/gui/pageindex.py", line 369, in get_indexpath
    return iter.indexpath
AttributeError: 'NoneType' object has no attribute 'indexpath'

Local variables in innermost frame:
treeiter: <GtkTreeIter at 0x5625251b9540>
self: <DuplicatePageTreeStore object at 0x7f5c3d79d140 (zim+gui+pageindex+PageTreeStore at 0x562525190a60)>
iter: None