Remove some comments and improved changelog

CHANGELOG.rst

@@ -120,9 +120,10 @@ time or change existing behaviors in order to make them less surprising/more use
     fixtures and reports them;
   + ``--setup-show``: performs normal test execution and additionally shows
     setup and teardown of fixtures;
-  + ``--keep-duplicates``: default behavior is now to ignore duplicate paths, you can  
+  + ``--keep-duplicates``: py.test now ignores duplicated paths given in the command
-    retain the old behavior and running multiple times the tests  
+    line. To retain the previous behavior where the same test could be run multiple
-    using the ``--keep-duplicates`` cli argument `#1609`_;
+    times by specifying it in the command-line multiple times, pass the ``--keep-duplicates``
+    argument (`#1609`_);
 
   Thanks `@d6e`_, `@kvas-it`_, `@sallner`_, `@ioggstream`_ and `@omarkohl`_ for the PRs.
 

_pytest/main.py

@@ -162,14 +162,10 @@ def pytest_ignore_collect(path, config):
         return True
 
     # Skip duplicate paths.
-    #  TODO: is this called when specifying direct filenames
-    #        from command lines, eg.
-    #        py.test test_a.py test_b.py
     keepduplicates = config.getoption("keepduplicates")
     duplicate_paths = config.pluginmanager._duplicatepaths
     if not keepduplicates:
         if path in duplicate_paths:
-            #  TODO should we log this?
             return True
         else:
             duplicate_paths.add(path)