avoid one surprising case of marker malfunction/confusion::

@pytest.mark.some(lambda arg: ...)
    def test_function():

would not work correctly because pytest assumes @pytest.mark.some
gets a function to be decorated already.  We now at least detect if this
arg is an lambda and thus the example will work.  Thanks Alex Gaynor
for bringing it up.

CHANGELOG

@@ -12,6 +12,16 @@ Changes between 2.4.2 and 2.4.3
   properly so that the pkg_resources.resource_stream method works properly.
   Fixes issue366.  Thanks for the investigations and full PR to Jason R. Coombs.
 
+- avoid one surprising case of marker malfunction/confusion::
+  
+      @pytest.mark.some(lambda arg: ...)
+      def test_function():
+
+  would not work correctly because pytest assumes @pytest.mark.some 
+  gets a function to be decorated already.  We now at least detect if this 
+  arg is an lambda and thus the example will work.  Thanks Alex Gaynor
+  for bringing it up.
+
 Changes between 2.4.1 and 2.4.2
 -----------------------------------
 

_pytest/mark.py

@@ -182,6 +182,9 @@ class MarkGenerator:
         if name not in self._markers:
             raise AttributeError("%r not a registered marker" % (name,))
 
+def istestfunc(func):
+    return hasattr(func, "__call__") and \
+        getattr(func, "__name__", "<lambda>") != "<lambda>"
 
 class MarkDecorator:
     """ A decorator for test functions and test classes.  When applied
@@ -217,8 +220,8 @@ class MarkDecorator:
             otherwise add *args/**kwargs in-place to mark information. """
         if args:
             func = args[0]
-            if len(args) == 1 and hasattr(func, '__call__') or \
+            if len(args) == 1 and (istestfunc(func) or
-               hasattr(func, '__bases__'):
+                                   hasattr(func, '__bases__')):
                 if hasattr(func, '__bases__'):
                     if hasattr(func, 'pytestmark'):
                         l = func.pytestmark

testing/test_mark.py

@@ -100,6 +100,16 @@ def test_markers_option(testdir):
         "*a1some*another marker",
     ])
 
+def test_mark_on_pseudo_function(testdir):
+    testdir.makepyfile("""
+        import pytest
+
+        @pytest.mark.r(lambda x: 0/0)
+        def test_hello():
+            pass
+    """)
+    reprec = testdir.inline_run()
+    reprec.assertoutcome(passed=1)
 
 def test_strict_prohibits_unregistered_markers(testdir):
     testdir.makepyfile("""
@@ -510,3 +520,4 @@ class TestKeywordSelection:
 
         assert_test_is_not_selected("__")
         assert_test_is_not_selected("()")
+