This issue was originally reported against the Fedora package of meld:
https://bugzilla.redhat.com/show_bug.cgi?id=722622

This backtrace occurs when model.value_path(child, pane) returns None:

backtrace:
:posixpath.py:112:basename:AttributeError: 'NoneType' object has no attribute
'rfind'
:
:Traceback (most recent call last):
:  File "/usr/share/meld/meld/meldwindow.py", line 568, in on_file_changed
:    page.on_file_changed(filename)
:  File "/usr/share/meld/meld/dirdiff.py", line 1121, in on_file_changed
:    name = os.path.basename(model.value_path(child, pane))
:  File "/usr/lib64/python2.7/posixpath.py", line 112, in basename
:    i = p.rfind('/') + 1
:AttributeError: 'NoneType' object has no attribute 'rfind'
:
:Local variables in innermost frame:
:p: None


This is quite reproducible on the command line, even if I don't know in which cases model.value_path returns None:

% python -c 'import os; os.path.basename(None)'
Traceback (most recent call last):

+ Trace 227801

An idea to resolve this issue would be to just call os.path.basename if model.value_path does not return None.