backout allowing @pytest.fixture in front of pytest_funcarg__NAME functions.

It was introduced because of pylint warnings and it's probably better to
go for a pylint-pytest plugin that avoids also other warnings/issues.

CHANGELOG

@@ -122,9 +122,6 @@ Unreleased
 
 - fix verbose reporting for @mock'd test functions
 
-- allow @pytest.fixture marked pytest_funcarg__foo functions
-  so that pylint errors can be avoided.
-
 Changes between 2.4.1 and 2.4.2
 -----------------------------------
 

_pytest/python.py

@@ -1654,9 +1654,8 @@ class FixtureManager:
                 # magic globals  with __getattr__ might have got us a wrong
                 # fixture attribute
                 continue
-            elif name.startswith(self._argprefix):
-                # let's allso fixture-marked pytest_funcarg__ prefixed functions
-                name = name[len(self._argprefix):]
+            else:
+                assert not name.startswith(self._argprefix)
             fixturedef = FixtureDef(self, nodeid, name, obj,
                                     marker.scope, marker.params,
                                     yieldctx=marker.yieldctx,

testing/python/integration.py

@@ -195,16 +195,3 @@ class TestReRunTests:
 def test_pytestconfig_is_session_scoped():
     from _pytest.python import pytestconfig
     assert pytestconfig._pytestfixturefunction.scope == "session"
-
-def test_funcarg_prefix_and_marker(testdir):
-    testdir.makepyfile("""
-        import pytest
-        @pytest.fixture
-        def pytest_funcarg__foo():
-            return 1
-
-        def test_hello(foo):
-            assert foo == 1
-    """)
-    reprec = testdir.inline_run()
-    reprec.assertoutcome(passed=1)