Fix teardown error message in generated xUnit XML

It was "test setup failure" even error happens on test teardown.

CHANGELOG.rst

@@ -20,7 +20,8 @@
 * Report teardown output on test failure (`#442`_).
   Thanks `@matclab`_ or the PR.
 
-*
+* Fix teardown error message in generated xUnit XML.
+  Thanks `@gdyuldin`_ or the PR.
 
 *
 
@@ -28,6 +29,7 @@
 .. _@cwitty: https://github.com/cwitty
 .. _@okulynyak: https://github.com/okulynyak
 .. _@matclab: https://github.com/matclab
+.. _@gdyuldin: https://github.com/gdyuldin
 
 .. _#442: https://github.com/pytest-dev/pytest/issues/442
 .. _#1976: https://github.com/pytest-dev/pytest/issues/1976

_pytest/junitxml.py

@@ -156,8 +156,12 @@ class _NodeReporter(object):
             Junit.skipped, "collection skipped", report.longrepr)
 
     def append_error(self, report):
+        if getattr(report, 'when', None) == 'teardown':
+            msg = "test teardown failure"
+        else:
+            msg = "test setup failure"
         self._add_simple(
-            Junit.error, "test setup failure", report.longrepr)
+            Junit.error, msg, report.longrepr)
         self._write_captured_output(report)
 
     def append_skipped(self, report):

testing/test_junitxml.py

@@ -165,6 +165,30 @@ class TestPython:
         fnode.assert_attr(message="test setup failure")
         assert "ValueError" in fnode.toxml()
 
+    def test_teardown_error(self, testdir):
+        testdir.makepyfile("""
+            import pytest
+
+            @pytest.fixture
+            def arg():
+                yield
+                raise ValueError()
+            def test_function(arg):
+                pass
+        """)
+        result, dom = runandparse(testdir)
+        assert result.ret
+        node = dom.find_first_by_tag("testsuite")
+        tnode = node.find_first_by_tag("testcase")
+        tnode.assert_attr(
+            file="test_teardown_error.py",
+            line="6",
+            classname="test_teardown_error",
+            name="test_function")
+        fnode = tnode.find_first_by_tag("error")
+        fnode.assert_attr(message="test teardown failure")
+        assert "ValueError" in fnode.toxml()
+
     def test_skip_contains_name_reason(self, testdir):
         testdir.makepyfile("""
             import pytest