Check word document validity before closing.

doc/changelog.txt

@@ -1,3 +1,10 @@
+8.4 "" (released xx.xx.2013)
+
+Fixes:
+- checking: Fix a crash when closing a Word document after scanning failed.
+  Closes: GH bug #369
+
+
 8.3 "Mahna Mahna Killer" (released 6.1.2013)
 
 Features:

linkcheck/checker/urlbase.py

@@ -1094,6 +1094,8 @@ class UrlBase (object):
             app = winutil.get_word_app()
             try:
                 doc = winutil.open_wordfile(app, filename)
+                if doc is None:
+                    raise winutil.Error("could not open word file %r" % filename)
                 try:
                     for link in doc.Hyperlinks:
                         self.add_url(link.Address, name=link.TextToDisplay)