commit 97b0fc46e3194d21b0a9c5515b98aaef91053762
Author: dsorber <david.sorber@gmail.com>
Date:   Sun Aug 20 13:42:18 2017 -0400

    Bale out if the user clicked cancel in the password dialog.

diff --git a/software/pwmgr/pwmgr.py b/software/pwmgr/pwmgr.py
index a5466b7..c56783f 100755
--- a/software/pwmgr/pwmgr.py
+++ b/software/pwmgr/pwmgr.py
@@ -42,26 +42,29 @@ def get_user_pw(parent, message, title=''):
     
     https://stackoverflow.com/questions/13970445/python-gtk3-how-to-add-a-gtk-entry-to-a-gtk-messagedialog
     """
-    dialogWindow = Gtk.MessageDialog(parent,
+    dialog = Gtk.MessageDialog(parent,
                                      Gtk.DialogFlags.MODAL | 
                                      Gtk.DialogFlags.DESTROY_WITH_PARENT,
                                      Gtk.MessageType.QUESTION,
                                      Gtk.ButtonsType.OK_CANCEL,
                                      message)
 
-    dialogWindow.set_title(title)
+    dialog.set_title(title)
 
-    dialogBox = dialogWindow.get_content_area()
-    userEntry = Gtk.Entry()
-    userEntry.set_visibility(False)
-    userEntry.set_invisible_char('*')
-    userEntry.set_size_request(200, 0)
-    dialogBox.pack_end(userEntry, False, False, 0)
+    box = dialog.get_content_area()
+    pw_entry = Gtk.Entry()
+    pw_entry.set_visibility(False)
+    pw_entry.set_invisible_char('*')
+    pw_entry.set_size_request(200, 0)
+    
+    box.add(pw_entry)
+    #~ box.pack_end(pw_entry, False, False, 0)
 
-    dialogWindow.show_all()
-    response = dialogWindow.run()
-    text = userEntry.get_text() 
-    dialogWindow.destroy()
+    dialog.show_all()
+    response = dialog.run()
+    text = pw_entry.get_text() 
+    dialog.destroy()
+    
     if (response == Gtk.ResponseType.OK) and (text != ''):
         return text
     else:
@@ -154,6 +157,9 @@ class TextViewWindow(Gtk.Window):
         
         # Get password
         self.pwd = get_user_pw(self, 'Please enter your password', 'Password')
+        if self.pwd is None:
+            return
+        
         #~ print('User entered: {:s}'.format(self.pwd))
         
         if not self.mounted: