diff --git a/.github/PULL_REQUEST_TEMPLATE.md b/.github/PULL_REQUEST_TEMPLATE.md
index ad3fea61ef9..bf9fc199f59 100644
--- a/.github/PULL_REQUEST_TEMPLATE.md
+++ b/.github/PULL_REQUEST_TEMPLATE.md
@@ -12,4 +12,4 @@ Here's a quick checklist that should be present in PRs:
 
 Unless your change is a trivial or a documentation fix (e.g.,  a typo or reword of a small section) please:
 
-- [ ] Add yourself to `AUTHORS`;
+- [ ] Add yourself to `AUTHORS`, in alphabetical order;
diff --git a/AUTHORS b/AUTHORS
index 0e75026ade5..aeef6dd9bc0 100644
--- a/AUTHORS
+++ b/AUTHORS
@@ -171,6 +171,7 @@ Tareq Alayan
 Ted Xiao
 Thomas Grainger
 Thomas Hisch
+Tom Dalton
 Tom Viner
 Trevor Bekolay
 Tyler Goodlet
diff --git a/CONTRIBUTING.rst b/CONTRIBUTING.rst
index 917ce3c338b..68db81398dd 100644
--- a/CONTRIBUTING.rst
+++ b/CONTRIBUTING.rst
@@ -177,7 +177,8 @@ Short version
 #. Write a ``changelog`` entry: ``changelog/2574.bugfix``, use issue id number
    and one of ``bugfix``, ``removal``, ``feature``, ``vendor``, ``doc`` or
    ``trivial`` for the issue type.
-#. Add yourself to ``AUTHORS`` file if not there yet, in alphabetical order.
+#. Unless your change is a trivial or a documentation fix (e.g., a typo or reword of a small section) please
+   add yourself to the ``AUTHORS`` file, in alphabetical order;
 
 
 Long version
diff --git a/_pytest/compat.py b/_pytest/compat.py
index 8499e888205..7560fbec397 100644
--- a/_pytest/compat.py
+++ b/_pytest/compat.py
@@ -14,7 +14,6 @@
 import _pytest
 from _pytest.outcomes import TEST_OUTCOME
 
-
 try:
     import enum
 except ImportError:  # pragma: no cover
@@ -110,11 +109,10 @@ def getfuncargnames(function, is_method=False, cls=None):
     # ordered mapping of parameter names to Parameter instances.  This
     # creates a tuple of the names of the parameters that don't have
     # defaults.
-    arg_names = tuple(
-        p.name for p in signature(function).parameters.values()
-        if (p.kind is Parameter.POSITIONAL_OR_KEYWORD
-            or p.kind is Parameter.KEYWORD_ONLY) and
-        p.default is Parameter.empty)
+    arg_names = tuple(p.name for p in signature(function).parameters.values()
+                      if (p.kind is Parameter.POSITIONAL_OR_KEYWORD or
+                          p.kind is Parameter.KEYWORD_ONLY) and
+                      p.default is Parameter.empty)
     # If this function should be treated as a bound method even though
     # it's passed as an unbound method or function, remove the first
     # parameter name.
@@ -129,8 +127,6 @@ def getfuncargnames(function, is_method=False, cls=None):
 
 
 if _PY3:
-    imap = map
-    izip = zip
     STRING_TYPES = bytes, str
     UNICODE_TYPES = str,
 
@@ -173,8 +169,6 @@ def ascii_escaped(val):
     STRING_TYPES = bytes, str, unicode
     UNICODE_TYPES = unicode,
 
-    from itertools import imap, izip  # NOQA
-
     def ascii_escaped(val):
         """In py2 bytes and str are the same type, so return if it's a bytes
         object, return it unchanged if it is a full ascii string,
diff --git a/_pytest/fixtures.py b/_pytest/fixtures.py
index 5ac93b1a921..596354ee318 100644
--- a/_pytest/fixtures.py
+++ b/_pytest/fixtures.py
@@ -1,13 +1,14 @@
 from __future__ import absolute_import, division, print_function
-import sys
 
-from py._code.code import FormattedExcinfo
+import inspect
+import sys
+import warnings
 
 import py
-import warnings
+from py._code.code import FormattedExcinfo
 
-import inspect
 import _pytest
+from _pytest import nodes
 from _pytest._code.code import TerminalRepr
 from _pytest.compat import (
     NOTSET, exc_clear, _format_args,
@@ -15,9 +16,10 @@
     is_generator, isclass, getimfunc,
     getlocation, getfuncargnames,
     safe_getattr,
+    FuncargnamesCompatAttr,
 )
 from _pytest.outcomes import fail, TEST_OUTCOME
-from _pytest.compat import FuncargnamesCompatAttr
+
 
 from collections import OrderedDict
 
@@ -977,8 +979,8 @@ def pytest_plugin_registered(self, plugin):
             # by their test id)
             if p.basename.startswith("conftest.py"):
                 nodeid = p.dirpath().relto(self.config.rootdir)
-                if p.sep != "/":
-                    nodeid = nodeid.replace(p.sep, "/")
+                if p.sep != nodes.SEP:
+                    nodeid = nodeid.replace(p.sep, nodes.SEP)
         self.parsefactories(plugin, nodeid)
 
     def _getautousenames(self, nodeid):
@@ -1033,9 +1035,14 @@ def pytest_generate_tests(self, metafunc):
             if faclist:
                 fixturedef = faclist[-1]
                 if fixturedef.params is not None:
-                    func_params = getattr(getattr(metafunc.function, 'parametrize', None), 'args', [[None]])
+                    parametrize_func = getattr(metafunc.function, 'parametrize', None)
+                    func_params = getattr(parametrize_func, 'args', [[None]])
+                    func_kwargs = getattr(parametrize_func, 'kwargs', {})
                     # skip directly parametrized arguments
-                    argnames = func_params[0]
+                    if "argnames" in func_kwargs:
+                        argnames = parametrize_func.kwargs["argnames"]
+                    else:
+                        argnames = func_params[0]
                     if not isinstance(argnames, (tuple, list)):
                         argnames = [x.strip() for x in argnames.split(",") if x.strip()]
                     if argname not in func_params and argname not in argnames:
@@ -1123,5 +1130,5 @@ def getfixturedefs(self, argname, nodeid):
 
     def _matchfactories(self, fixturedefs, nodeid):
         for fixturedef in fixturedefs:
-            if nodeid.startswith(fixturedef.baseid):
+            if nodes.ischildnode(fixturedef.baseid, nodeid):
                 yield fixturedef
diff --git a/_pytest/junitxml.py b/_pytest/junitxml.py
index ed3ba2e9a53..7fb40dc3548 100644
--- a/_pytest/junitxml.py
+++ b/_pytest/junitxml.py
@@ -17,6 +17,7 @@
 import sys
 import time
 import pytest
+from _pytest import nodes
 from _pytest.config import filename_arg
 
 # Python 2.X and 3.X compatibility
@@ -252,7 +253,7 @@ def mangle_test_address(address):
     except ValueError:
         pass
     # convert file path to dotted path
-    names[0] = names[0].replace("/", '.')
+    names[0] = names[0].replace(nodes.SEP, '.')
     names[0] = _py_ext_re.sub("", names[0])
     # put any params back
     names[-1] += possible_open_bracket + params
diff --git a/_pytest/main.py b/_pytest/main.py
index f7c3fe48083..a2d61b44245 100644
--- a/_pytest/main.py
+++ b/_pytest/main.py
@@ -7,6 +7,7 @@
 import sys
 
 import _pytest
+from _pytest import nodes
 import _pytest._code
 import py
 try:
@@ -15,8 +16,8 @@
     from UserDict import DictMixin as MappingMixin
 
 from _pytest.config import directory_arg, UsageError, hookimpl
-from _pytest.runner import collect_one_node
 from _pytest.outcomes import exit
+from _pytest.runner import collect_one_node
 
 tracebackcutdir = py.path.local(_pytest.__file__).dirpath()
 
@@ -494,14 +495,14 @@ def __init__(self, fspath, parent=None, config=None, session=None):
             rel = fspath.relto(parent.fspath)
             if rel:
                 name = rel
-            name = name.replace(os.sep, "/")
+            name = name.replace(os.sep, nodes.SEP)
         super(FSCollector, self).__init__(name, parent, config, session)
         self.fspath = fspath
 
     def _makeid(self):
         relpath = self.fspath.relto(self.config.rootdir)
-        if os.sep != "/":
-            relpath = relpath.replace(os.sep, "/")
+        if os.sep != nodes.SEP:
+            relpath = relpath.replace(os.sep, nodes.SEP)
         return relpath
 
 
diff --git a/_pytest/mark.py b/_pytest/mark.py
index 547a94e4ba4..03b058d95b9 100644
--- a/_pytest/mark.py
+++ b/_pytest/mark.py
@@ -5,7 +5,7 @@
 import warnings
 from collections import namedtuple
 from operator import attrgetter
-from .compat import imap
+from six.moves import map
 from .deprecated import MARK_PARAMETERSET_UNPACKING
 
 
@@ -379,7 +379,7 @@ def store_mark(obj, mark):
     """
     assert isinstance(mark, Mark), mark
     # always reassign name to avoid updating pytestmark
-    # in a referene that was only borrowed
+    # in a reference that was only borrowed
     obj.pytestmark = get_unpacked_marks(obj) + [mark]
 
 
@@ -427,7 +427,7 @@ def add_mark(self, mark):
 
     def __iter__(self):
         """ yield MarkInfo objects each relating to a marking-call. """
-        return imap(MarkInfo, self._marks)
+        return map(MarkInfo, self._marks)
 
 
 MARK_GEN = MarkGenerator()
diff --git a/_pytest/nodes.py b/_pytest/nodes.py
new file mode 100644
index 00000000000..ad3af2ce67c
--- /dev/null
+++ b/_pytest/nodes.py
@@ -0,0 +1,37 @@
+SEP = "/"
+
+
+def _splitnode(nodeid):
+    """Split a nodeid into constituent 'parts'.
+
+    Node IDs are strings, and can be things like:
+        ''
+        'testing/code'
+        'testing/code/test_excinfo.py'
+        'testing/code/test_excinfo.py::TestFormattedExcinfo::()'
+
+    Return values are lists e.g.
+        []
+        ['testing', 'code']
+        ['testing', 'code', 'test_excinfo.py']
+        ['testing', 'code', 'test_excinfo.py', 'TestFormattedExcinfo', '()']
+    """
+    if nodeid == '':
+        # If there is no root node at all, return an empty list so the caller's logic can remain sane
+        return []
+    parts = nodeid.split(SEP)
+    # Replace single last element 'test_foo.py::Bar::()' with multiple elements 'test_foo.py', 'Bar', '()'
+    parts[-1:] = parts[-1].split("::")
+    return parts
+
+
+def ischildnode(baseid, nodeid):
+    """Return True if the nodeid is a child node of the baseid.
+
+    E.g. 'foo/bar::Baz::()' is a child of 'foo', 'foo/bar' and 'foo/bar::Baz', but not of 'foo/blorp'
+    """
+    base_parts = _splitnode(baseid)
+    node_parts = _splitnode(nodeid)
+    if len(node_parts) < len(base_parts):
+        return False
+    return node_parts[:len(base_parts)] == base_parts
diff --git a/_pytest/pytester.py b/_pytest/pytester.py
index 345a1acd0f4..a65e3f02704 100644
--- a/_pytest/pytester.py
+++ b/_pytest/pytester.py
@@ -23,9 +23,7 @@
 from _pytest.assertion.rewrite import AssertionRewritingHook
 
 
-PYTEST_FULLPATH = os.path.abspath(
-    pytest.__file__.rstrip("oc")
-    ).replace("$py.class", ".py")
+PYTEST_FULLPATH = os.path.abspath(pytest.__file__.rstrip("oc")).replace("$py.class", ".py")
 
 
 def pytest_addoption(parser):
diff --git a/_pytest/python_api.py b/_pytest/python_api.py
index b52f688107a..bf1cd147e06 100644
--- a/_pytest/python_api.py
+++ b/_pytest/python_api.py
@@ -2,8 +2,9 @@
 import sys
 
 import py
+from six.moves import zip
 
-from _pytest.compat import isclass, izip
+from _pytest.compat import isclass
 from _pytest.outcomes import fail
 import _pytest._code
 
@@ -145,7 +146,7 @@ def __eq__(self, actual):
         return ApproxBase.__eq__(self, actual)
 
     def _yield_comparisons(self, actual):
-        return izip(actual, self.expected)
+        return zip(actual, self.expected)
 
 
 class ApproxScalar(ApproxBase):
@@ -217,7 +218,8 @@ def tolerance(self):
         absolute tolerance or a relative tolerance, depending on what the user
         specified or which would be larger.
         """
-        def set_default(x, default): return x if x is not None else default
+        def set_default(x, default):
+            return x if x is not None else default
 
         # Figure out what the absolute tolerance should be.  ``self.abs`` is
         # either None or a value specified by the user.
diff --git a/_pytest/recwarn.py b/_pytest/recwarn.py
index c9f86a4839a..4fceb10a7f3 100644
--- a/_pytest/recwarn.py
+++ b/_pytest/recwarn.py
@@ -232,7 +232,5 @@ def __exit__(self, *exc_info):
                     else:
                         fail("DID NOT WARN. No warnings of type {0} matching"
                              " ('{1}') was emitted. The list of emitted warnings"
-                             " is: {2}.".format(
-                                self.expected_warning,
-                                self.match_expr,
-                                [each.message for each in self]))
+                             " is: {2}.".format(self.expected_warning, self.match_expr,
+                                                [each.message for each in self]))
diff --git a/_pytest/terminal.py b/_pytest/terminal.py
index 92f319766b6..cb4823ff3c4 100644
--- a/_pytest/terminal.py
+++ b/_pytest/terminal.py
@@ -10,11 +10,12 @@
 import time
 import warnings
 
+import pluggy
 import py
 import six
 
-import pluggy
 import pytest
+from _pytest import nodes
 from _pytest.main import EXIT_OK, EXIT_TESTSFAILED, EXIT_INTERRUPTED, \
     EXIT_USAGEERROR, EXIT_NOTESTSCOLLECTED
 
@@ -466,7 +467,7 @@ def mkrel(nodeid):
 
         if fspath:
             res = mkrel(nodeid).replace("::()", "")  # parens-normalization
-            if nodeid.split("::")[0] != fspath.replace("\\", "/"):
+            if nodeid.split("::")[0] != fspath.replace("\\", nodes.SEP):
                 res += " <- " + self.startdir.bestrelpath(fspath)
         else:
             res = "[location]"
diff --git a/changelog/1997.doc b/changelog/1997.doc
new file mode 100644
index 00000000000..0fa110dc9ab
--- /dev/null
+++ b/changelog/1997.doc
@@ -0,0 +1 @@
+Explicitly mention ``xpass`` in the documentation of ``xfail``.
diff --git a/changelog/2819.bugfix b/changelog/2819.bugfix
new file mode 100644
index 00000000000..303903cf745
--- /dev/null
+++ b/changelog/2819.bugfix
@@ -0,0 +1 @@
+Fix issue with @pytest.parametrize if argnames was specified as kwarg.
\ No newline at end of file
diff --git a/changelog/2836.bug b/changelog/2836.bug
new file mode 100644
index 00000000000..afa1961d73e
--- /dev/null
+++ b/changelog/2836.bug
@@ -0,0 +1 @@
+Match fixture paths against actual path segments in order to avoid matching folders which share a prefix.
diff --git a/changelog/538.doc b/changelog/538.doc
new file mode 100644
index 00000000000..bc5fb712fa4
--- /dev/null
+++ b/changelog/538.doc
@@ -0,0 +1 @@
+Clarify the documentation of available fixture scopes.
diff --git a/changelog/911.doc b/changelog/911.doc
new file mode 100644
index 00000000000..e9d94f21ce8
--- /dev/null
+++ b/changelog/911.doc
@@ -0,0 +1 @@
+Add documentation about the ``python -m pytest`` invocation adding the current directory to sys.path.
diff --git a/doc/en/example/parametrize.rst b/doc/en/example/parametrize.rst
index b72e8e6de3a..ffeb5a951be 100644
--- a/doc/en/example/parametrize.rst
+++ b/doc/en/example/parametrize.rst
@@ -350,7 +350,7 @@ Parametrizing test methods through per-class configuration
 .. _`unittest parametrizer`: https://github.com/testing-cabal/unittest-ext/blob/master/params.py
 
 
-Here is an example ``pytest_generate_function`` function implementing a
+Here is an example ``pytest_generate_tests`` function implementing a
 parametrization scheme similar to Michael Foord's `unittest
 parametrizer`_ but in a lot less code::
 
diff --git a/doc/en/fixture.rst b/doc/en/fixture.rst
index db7ef0ca2e4..dace0514e87 100644
--- a/doc/en/fixture.rst
+++ b/doc/en/fixture.rst
@@ -27,7 +27,7 @@ functions:
 * fixture management scales from simple unit to complex
   functional testing, allowing to parametrize fixtures and tests according
   to configuration and component options, or to re-use fixtures
-  across class, module or whole test session scopes.
+  across function, class, module or whole test session scopes.
 
 In addition, pytest continues to support :ref:`xunitsetup`.  You can mix
 both styles, moving incrementally from classic to new style, as you
@@ -129,8 +129,8 @@ functions take the role of the *injector* and test functions are the
 
 .. _smtpshared:
 
-Sharing a fixture across tests in a module (or class/session)
------------------------------------------------------------------
+Scope: Sharing a fixture across tests in a class, module or session
+-------------------------------------------------------------------
 
 .. regendoc:wipe
 
@@ -139,10 +139,12 @@ usually time-expensive to create.  Extending the previous example, we
 can add a ``scope='module'`` parameter to the
 :py:func:`@pytest.fixture <_pytest.python.fixture>` invocation
 to cause the decorated ``smtp`` fixture function to only be invoked once
-per test module.  Multiple test functions in a test module will thus
-each receive the same ``smtp`` fixture instance.  The next example puts
-the fixture function into a separate ``conftest.py`` file so
-that tests from multiple test modules in the directory can
+per test *module* (the default is to invoke once per test *function*).
+Multiple test functions in a test module will thus
+each receive the same ``smtp`` fixture instance, thus saving time.
+
+The next example puts the fixture function into a separate ``conftest.py`` file 
+so that tests from multiple test modules in the directory can
 access the fixture function::
 
     # content of conftest.py
@@ -223,6 +225,8 @@ instance, you can simply declare it:
         # the returned fixture value will be shared for
         # all tests needing it
 
+Finally, the ``class`` scope will invoke the fixture once per test *class*.
+
 .. _`finalization`:
 
 Fixture finalization / executing teardown code
@@ -858,7 +862,7 @@ into a conftest.py file **without** using ``autouse``::
 
     # content of conftest.py
     @pytest.fixture
-    def transact(self, request, db):
+    def transact(request, db):
         db.begin()
         yield
         db.rollback()
diff --git a/doc/en/pythonpath.rst b/doc/en/pythonpath.rst
index 67de7f5d2ca..b6474276887 100644
--- a/doc/en/pythonpath.rst
+++ b/doc/en/pythonpath.rst
@@ -68,4 +68,9 @@ imported in the global import namespace.
 
 This is also discussed in details in :ref:`test discovery`.
 
+Invoking ``pytest`` versus ``python -m pytest``
+-----------------------------------------------
 
+Running pytest with ``python -m pytest [...]`` instead of ``pytest [...]`` yields nearly
+equivalent behaviour, except that the former call will add the current directory to ``sys.path``.
+See also :ref:`cmdline`.
diff --git a/doc/en/skipping.rst b/doc/en/skipping.rst
index 79c4385ca3c..dbe9c7f8d58 100644
--- a/doc/en/skipping.rst
+++ b/doc/en/skipping.rst
@@ -16,13 +16,17 @@ resource which is not available at the moment (for example a database).
 
 A **xfail** means that you expect a test to fail for some reason.
 A common example is a test for a feature not yet implemented, or a bug not yet fixed.
+When a test passes despite being expected to fail (marked with ``pytest.mark.xfail``),
+it's an **xpass** and will be reported in the test summary.
 
 ``pytest`` counts and lists *skip* and *xfail* tests separately. Detailed
 information about skipped/xfailed tests is not shown by default to avoid
 cluttering the output.  You can use the ``-r`` option to see details
 corresponding to the "short" letters shown in the test progress::
 
-    pytest -rxs  # show extra info on skips and xfails
+    pytest -rxXs  # show extra info on xfailed, xpassed, and skipped tests
+
+More details on the ``-r`` option can be found by running ``pytest -h``.
 
 (See :ref:`how to change command line options defaults`)
 
diff --git a/doc/en/unittest.rst b/doc/en/unittest.rst
index 92b9e653eee..db169202935 100644
--- a/doc/en/unittest.rst
+++ b/doc/en/unittest.rst
@@ -233,3 +233,13 @@ was executed ahead of the ``test_method``.
     overwrite ``unittest.TestCase`` ``__call__`` or ``run``, they need to
     to overwrite ``debug`` in the same way  (this is also true for standard
     unittest).
+
+.. note::
+
+    Due to architectural differences between the two frameworks, setup and
+    teardown for ``unittest``-based tests is performed during the ``call`` phase
+    of testing instead of in ``pytest``'s standard ``setup`` and ``teardown``
+    stages. This can be important to understand in some situations, particularly
+    when reasoning about errors. For example, if a ``unittest``-based suite
+    exhibits errors during setup, ``pytest`` will report no errors during its
+    ``setup`` phase and will instead raise the error during ``call``.
diff --git a/doc/en/usage.rst b/doc/en/usage.rst
index 1cb64ec8745..6091db8be38 100644
--- a/doc/en/usage.rst
+++ b/doc/en/usage.rst
@@ -17,7 +17,7 @@ You can invoke testing through the Python interpreter from the command line::
     python -m pytest [...]
 
 This is almost equivalent to invoking the command line script ``pytest [...]``
-directly, except that Python will also add the current directory to ``sys.path``.
+directly, except that calling via ``python`` will also add the current directory to ``sys.path``.
 
 Possible exit codes
 --------------------------------------------------------------
diff --git a/doc/en/warnings.rst b/doc/en/warnings.rst
index ac26068c4fd..87faeb7bd33 100644
--- a/doc/en/warnings.rst
+++ b/doc/en/warnings.rst
@@ -109,7 +109,7 @@ decorator or to all tests in a module by setting the ``pytestmark`` variable:
 .. code-block:: python
 
     # turns all warnings into errors for this module
-    pytestmark = @pytest.mark.filterwarnings('error')
+    pytestmark = pytest.mark.filterwarnings('error')
 
 
 .. note::
diff --git a/testing/logging/test_fixture.py b/testing/logging/test_fixture.py
index b5bee4233a5..c27b31137ff 100644
--- a/testing/logging/test_fixture.py
+++ b/testing/logging/test_fixture.py
@@ -3,7 +3,7 @@
 
 
 logger = logging.getLogger(__name__)
-sublogger = logging.getLogger(__name__+'.baz')
+sublogger = logging.getLogger(__name__ + '.baz')
 
 
 def test_fixture_help(testdir):
diff --git a/testing/test_collection.py b/testing/test_collection.py
index eb2814527bc..016c3e61b59 100644
--- a/testing/test_collection.py
+++ b/testing/test_collection.py
@@ -2,6 +2,7 @@
 import pytest
 import py
 
+import _pytest._code
 from _pytest.main import Session, EXIT_NOTESTSCOLLECTED, _in_venv
 
 
@@ -829,3 +830,28 @@ def test_continue_on_collection_errors_maxfail(testdir):
         "collected 2 items / 2 errors",
         "*1 failed, 2 error*",
     ])
+
+
+def test_fixture_scope_sibling_conftests(testdir):
+    """Regression test case for https://github.com/pytest-dev/pytest/issues/2836"""
+    foo_path = testdir.mkpydir("foo")
+    foo_path.join("conftest.py").write(_pytest._code.Source("""
+        import pytest
+        @pytest.fixture
+        def fix():
+            return 1
+    """))
+    foo_path.join("test_foo.py").write("def test_foo(fix): assert fix == 1")
+
+    # Tests in `food/` should not see the conftest fixture from `foo/`
+    food_path = testdir.mkpydir("food")
+    food_path.join("test_food.py").write("def test_food(fix): assert fix == 1")
+
+    res = testdir.runpytest()
+    assert res.ret == 1
+
+    res.stdout.fnmatch_lines([
+        "*ERROR at setup of test_food*",
+        "E*fixture 'fix' not found",
+        "*1 passed, 1 error*",
+    ])
diff --git a/testing/test_mark.py b/testing/test_mark.py
index ae070f3a0f9..dc51bbac0f2 100644
--- a/testing/test_mark.py
+++ b/testing/test_mark.py
@@ -342,6 +342,24 @@ def test_func(foo, bar):
     ])
 
 
+def test_parametrized_with_kwargs(testdir):
+    """Test collect parametrized func with wrong number of args."""
+    py_file = testdir.makepyfile("""
+        import pytest
+
+        @pytest.fixture(params=[1,2])
+        def a(request):
+            return request.param
+
+        @pytest.mark.parametrize(argnames='b', argvalues=[1, 2])
+        def test_func(a, b):
+            pass
+    """)
+
+    result = testdir.runpytest(py_file)
+    assert(result.ret == 0)
+
+
 class TestFunctional(object):
 
     def test_mark_per_function(self, testdir):
diff --git a/testing/test_nodes.py b/testing/test_nodes.py
new file mode 100644
index 00000000000..6f4540f99b9
--- /dev/null
+++ b/testing/test_nodes.py
@@ -0,0 +1,18 @@
+import pytest
+
+from _pytest import nodes
+
+
+@pytest.mark.parametrize("baseid, nodeid, expected", (
+    ('', '', True),
+    ('', 'foo', True),
+    ('', 'foo/bar', True),
+    ('', 'foo/bar::TestBaz::()', True),
+    ('foo', 'food', False),
+    ('foo/bar::TestBaz::()', 'foo/bar', False),
+    ('foo/bar::TestBaz::()', 'foo/bar::TestBop::()', False),
+    ('foo/bar', 'foo/bar::TestBop::()', True),
+))
+def test_ischildnode(baseid, nodeid, expected):
+    result = nodes.ischildnode(baseid, nodeid)
+    assert result is expected
diff --git a/tox.ini b/tox.ini
index b774cbda5d0..aaf39026b1d 100644
--- a/tox.ini
+++ b/tox.ini
@@ -216,3 +216,8 @@ filterwarnings =
 
 [flake8]
 max-line-length = 120
+ignore=
+    # do not use bare except'
+    E722
+    # ambiguous variable name 'l'
+    E741