fix issue #1618 by considering plugin args first

additionally prevent unnecessary importation of blocked plugins

Author: RonnyPfannschmidt

_pytest/config.py

@@ -375,7 +375,7 @@ def import_plugin(self, modname):
         # basename for historic purposes but must be imported with the
         # _pytest prefix.
         assert isinstance(modname, str)
-        if self.get_plugin(modname) is not None:
+        if self.get_plugin(modname) is not None or self.is_blocked(modname):
             return
         if modname in builtin_plugins:
             importspec = "_pytest." + modname
@@ -893,9 +893,9 @@ def fromdictargs(cls, option_dict, args):
         """ constructor useable for subprocesses. """
         config = get_config()
         config.option.__dict__.update(option_dict)
-        config.parse(args, addopts=False)
         for x in config.option.plugins:
             config.pluginmanager.consider_pluginarg(x)
+        config.parse(args, addopts=False)
         return config
 
     def _processopt(self, opt):

testing/test_config.py

@@ -79,7 +79,7 @@ def test_confcutdir(self, testdir):
         """)
         result = testdir.inline_run("--confcutdir=.")
         assert result.ret == 0
-        
+
 class TestConfigCmdlineParsing:
     def test_parsing_again_fails(self, testdir):
         config = testdir.parseconfig()
@@ -352,6 +352,24 @@ def test_inifilename(self, tmpdir):
         assert config.inicfg.get('name') == 'value'
         assert config.inicfg.get('should_not_be_set') is None
 
+    def test_consider_plugin(self, testdir):
+        pytest.importorskip('xdist')
+        print testdir
+        testdir.makepyfile(conftest="""
+                pytest_plugins = ['plugin']
+            """,
+            plugin="""
+                raise ImportError
+            """,
+            test_foo="""
+                def test():
+                    pass
+            """,
+        )
+        testdir.inline_run(
+            '-n1',
+            '-p', 'no:plugin')
+
 
 def test_options_on_small_file_do_not_blow_up(testdir):
     def runfiletest(opts):