avoid prepend to register api as it's redundant wrt to hooks

--HG--
branch : plugin_no_pytest

_pytest/core.py

@@ -205,7 +205,7 @@ class PluginManager(object):
                            ", ".join(hook.argnames))
             yield hook
 
-    def register(self, plugin, name=None, prepend=False, conftest=False):
+    def register(self, plugin, name=None, conftest=False):
         if self._name2plugin.get(name, None) == -1:
             return
         name = name or getattr(plugin, '__name__', str(id(plugin)))
@@ -222,10 +222,7 @@ class PluginManager(object):
         if conftest:
             self._conftestplugins.append(plugin)
         else:
-            if not prepend:
-                self._plugins.append(plugin)
-            else:
-                self._plugins.insert(0, plugin)
+            self._plugins.append(plugin)
         # finally make sure that the methods of the new plugin take part
         for hookcaller in hookcallers:
             hookcaller.scan_methods()

_pytest/main.py

@@ -510,7 +510,7 @@ class Session(FSCollector):
     def __init__(self, config):
         FSCollector.__init__(self, config.rootdir, parent=None,
                              config=config, session=self)
-        self.config.pluginmanager.register(self, name="session", prepend=True)
+        self.config.pluginmanager.register(self, name="session")
         self._testsfailed = 0
         self.shouldstop = False
         self.trace = config.trace.root.get("collection")
@@ -521,10 +521,12 @@ class Session(FSCollector):
     def _makeid(self):
         return ""
 
+    @pytest.mark.tryfirst
     def pytest_collectstart(self):
         if self.shouldstop:
             raise self.Interrupted(self.shouldstop)
 
+    @pytest.mark.tryfirst
     def pytest_runtest_logreport(self, report):
         if report.failed and not hasattr(report, 'wasxfail'):
             self._testsfailed += 1

testing/test_core.py

@@ -32,18 +32,6 @@ class TestPluginManager:
         pm.unregister(a1)
         assert not pm.isregistered(a1)
 
-    def test_pm_ordering(self, pm):
-        class A: pass
-        a1, a2 = A(), A()
-        pm.register(a1)
-        pm.register(a2, "hello")
-        l = pm.getplugins()
-        assert l.index(a1) < l.index(a2)
-        a3 = A()
-        pm.register(a3, prepend=True)
-        l = pm.getplugins()
-        assert l.index(a3) == 0
-
     def test_register_mismatch_method(self):
         pm = get_plugin_manager()
         class hello: