Fix crash that happened under --runxfail -o empty_parameter_set_mark=xfail

src/_pytest/mark/structures.py

@@ -37,6 +37,9 @@ def get_empty_parameterset_mark(config, argnames, func):
     if requested_mark in ("", None, "skip"):
         mark = MARK_GEN.skip
     elif requested_mark == "xfail":
+        if config.getoption("runxfail", default=False):
+            mark = MARK_GEN.skip
+        else:
             mark = MARK_GEN.xfail(run=False)
     elif requested_mark == "fail_at_collect":
         f_name = func.__name__

testing/test_mark.py

@@ -885,15 +885,19 @@ class TestMarkDecorator:
         assert md.kwargs == {"three": 3}
 
 
-@pytest.mark.parametrize("mark", [None, "", "skip", "xfail"])
-def test_parameterset_for_parametrize_marks(testdir, mark):
+@pytest.mark.parametrize(
+    "mark, addopts",
+    [(None, ""), ("", ""), ("skip", ""), ("xfail", ""), ("xfail", "--runxfail")],
+)
+def test_parameterset_for_parametrize_marks(testdir, mark, addopts):
     if mark is not None:
         testdir.makeini(
             """
         [pytest]
         {}={}
+        addopts={}
         """.format(
-                EMPTY_PARAMETERSET_OPTION, mark
+                EMPTY_PARAMETERSET_OPTION, mark, addopts
             )
         )
 
@@ -902,7 +906,7 @@ def test_parameterset_for_parametrize_marks(testdir, mark):
 
     pytest_configure(config)
     result_mark = get_empty_parameterset_mark(config, ["a"], all)
-    if mark in (None, ""):
+    if mark in (None, "") or (mark == "xfail" and addopts == "--runxfail"):
         # normalize to the requested name
         mark = "skip"
     assert result_mark.name == mark
@@ -955,7 +959,7 @@ def test_parameterset_for_fail_at_collect(testdir):
 
 def test_parameterset_for_parametrize_bad_markname(testdir):
     with pytest.raises(pytest.UsageError):
-        test_parameterset_for_parametrize_marks(testdir, "bad")
+        test_parameterset_for_parametrize_marks(testdir, "bad", False)
 
 
 def test_mark_expressions_no_smear(testdir):