From a50b92ea67ed46374c63486ce554245be9ca71e8 Mon Sep 17 00:00:00 2001
From: Daniel Hahler <git@thequod.de>
Date: Tue, 19 Mar 2019 22:30:50 +0100
Subject: [PATCH] pytester: set HOME only with inline_run/popen

Ref: https://github.com/pytest-dev/pytest/issues/4955
---
 changelog/4941.feature.rst |  3 ---
 changelog/4956.feature.rst |  3 +++
 src/_pytest/pytester.py    | 12 ++++++++++--
 testing/test_junitxml.py   |  3 ++-
 4 files changed, 15 insertions(+), 6 deletions(-)
 delete mode 100644 changelog/4941.feature.rst
 create mode 100644 changelog/4956.feature.rst

diff --git a/changelog/4941.feature.rst b/changelog/4941.feature.rst
deleted file mode 100644
index 846b43f45..000000000
--- a/changelog/4941.feature.rst
+++ /dev/null
@@ -1,3 +0,0 @@
-``pytester``'s ``Testdir`` sets ``$HOME`` and ``$USERPROFILE`` to the temporary directory.
-
-This ensures to not load configuration files from the real user's home directory.
diff --git a/changelog/4956.feature.rst b/changelog/4956.feature.rst
new file mode 100644
index 000000000..1dfbd7e97
--- /dev/null
+++ b/changelog/4956.feature.rst
@@ -0,0 +1,3 @@
+``pytester`` sets ``$HOME`` and ``$USERPROFILE`` to the temporary directory during test runs.
+
+This ensures to not load configuration files from the real user's home directory.
diff --git a/src/_pytest/pytester.py b/src/_pytest/pytester.py
index 8f1a7d1d5..ffcd2982a 100644
--- a/src/_pytest/pytester.py
+++ b/src/_pytest/pytester.py
@@ -29,6 +29,7 @@ from _pytest.compat import Sequence
 from _pytest.main import EXIT_INTERRUPTED
 from _pytest.main import EXIT_OK
 from _pytest.main import Session
+from _pytest.monkeypatch import MonkeyPatch
 from _pytest.pathlib import Path
 
 IGNORE_PAM = [  # filenames added when obtaining details about the current user
@@ -469,8 +470,6 @@ class Testdir(object):
         os.environ["PYTEST_DEBUG_TEMPROOT"] = str(self.test_tmproot)
         os.environ.pop("TOX_ENV_DIR", None)  # Ensure that it is not used for caching.
         os.environ.pop("PYTEST_ADDOPTS", None)  # Do not use outer options.
-        os.environ["HOME"] = str(self.tmpdir)  # Do not load user config.
-        os.environ["USERPROFILE"] = os.environ["HOME"]
         self.plugins = []
         self._cwd_snapshot = CwdSnapshot()
         self._sys_path_snapshot = SysPathsSnapshot()
@@ -788,6 +787,12 @@ class Testdir(object):
         """
         finalizers = []
         try:
+            # Do not load user config.
+            monkeypatch = MonkeyPatch()
+            monkeypatch.setenv("HOME", str(self.tmpdir))
+            monkeypatch.setenv("USERPROFILE", str(self.tmpdir))
+            finalizers.append(monkeypatch.undo)
+
             # When running pytest inline any plugins active in the main test
             # process are already imported.  So this disables the warning which
             # will trigger to say they can no longer be rewritten, which is
@@ -1018,6 +1023,9 @@ class Testdir(object):
         env["PYTHONPATH"] = os.pathsep.join(
             filter(None, [os.getcwd(), env.get("PYTHONPATH", "")])
         )
+        # Do not load user config.
+        env["HOME"] = str(self.tmpdir)
+        env["USERPROFILE"] = env["HOME"]
         kw["env"] = env
 
         popen = subprocess.Popen(
diff --git a/testing/test_junitxml.py b/testing/test_junitxml.py
index 4748aa581..769e8e8a7 100644
--- a/testing/test_junitxml.py
+++ b/testing/test_junitxml.py
@@ -816,11 +816,12 @@ def test_invalid_xml_escape():
         assert chr(i) == bin_xml_escape(unichr(i)).uniobj
 
 
-def test_logxml_path_expansion(tmpdir):
+def test_logxml_path_expansion(tmpdir, monkeypatch):
     home_tilde = py.path.local(os.path.expanduser("~")).join("test.xml")
     xml_tilde = LogXML("~%stest.xml" % tmpdir.sep, None)
     assert xml_tilde.logfile == home_tilde
 
+    monkeypatch.setenv("HOME", str(tmpdir))
     home_var = os.path.normpath(os.path.expandvars("$HOME/test.xml"))
     xml_var = LogXML("$HOME%stest.xml" % tmpdir.sep, None)
     assert xml_var.logfile == home_var