Merge master into features

src/_pytest/capture.py

@@ -117,7 +117,10 @@ class CaptureManager(object):
             self._global_capturing = None
 
     def resume_global_capture(self):
-        self._global_capturing.resume_capturing()
+        # During teardown of the python process, and on rare occasions, capture
+        # attributes can be `None` while trying to resume global capture.
+        if self._global_capturing is not None:
+            self._global_capturing.resume_capturing()
 
     def suspend_global_capture(self, in_=False):
         cap = getattr(self, "_global_capturing", None)

src/_pytest/config/__init__.py

@@ -777,12 +777,21 @@ class Config(object):
         for name in _iter_rewritable_modules(package_files):
             hook.mark_rewrite(name)
 
+    def _validate_args(self, args):
+        """Validate known args."""
+        self._parser.parse_known_and_unknown_args(
+            args, namespace=copy.copy(self.option)
+        )
+        return args
+
     def _preparse(self, args, addopts=True):
         if addopts:
-            args[:] = shlex.split(os.environ.get("PYTEST_ADDOPTS", "")) + args
+            env_addopts = os.environ.get("PYTEST_ADDOPTS", "")
+            if len(env_addopts):
+                args[:] = self._validate_args(shlex.split(env_addopts)) + args
         self._initini(args)
         if addopts:
-            args[:] = self.getini("addopts") + args
+            args[:] = self._validate_args(self.getini("addopts")) + args
         self._checkversion()
         self._consider_importhook(args)
         self.pluginmanager.consider_preparse(args)