make initial conftest finding ignore "--" arguments

--HG--
branch : trunk

CHANGELOG

@@ -55,6 +55,7 @@ Bug fixes / Maintenance
   get canonical script paths in virtualenv situations
 - make path.bestrelpath(path) return ".", note that when calling 
   X.bestrelpath the assumption is that X is a directory. 
+- make initial conftest discovery ignore "--" prefixed arguments 
 
 Changes between 1.3.0 and 1.3.1
 ==================================================

py/_test/conftesthandle.py

@@ -36,6 +36,8 @@ class Conftest(object):
                 self._confcutdir = p 
                 break
         for arg in args + [current]:
+            if hasattr(arg, 'startswith') and arg.startswith("--"):
+                continue
             anchor = current.join(arg, abs=1)
             if anchor.check(): # we found some file object 
                 self._path2confmods[None] = self.getconftestmodules(anchor)

testing/test_conftesthandle.py

@@ -98,6 +98,14 @@ def test_conftest_in_nonpkg_with_init(tmpdir):
     tmpdir.ensure("adir-1.0/__init__.py")
     conftest = ConftestWithSetinitial(tmpdir.join("adir-1.0", "b"))
 
+def test_doubledash_not_considered(testdir):
+    conf = testdir.mkdir("--option")
+    conf.join("conftest.py").ensure()
+    conftest = Conftest()
+    conftest.setinitial([conf.basename, conf.basename])
+    l = conftest.getconftestmodules(None)
+    assert len(l) == 0
+
 def test_conftestcutdir(testdir):
     conf = testdir.makeconftest("")
     p = testdir.mkdir("x")