[coverage] fix a bug breaking coverage.py (closes #281908)

The refactoring of the coverage suspend/resume tools in pytest done in
31725b8fa3f5 breaks the compatibility of theses tools with coverage.py,
due to a bug in this later project, see:

  https://bitbucket.org/ned/coveragepy/issue/123

1 files changed, 5 insertions, 0 deletions

diff --git a/pytest.py b/pytest.py
index c0f84ac..58515a9 100644
--- a/pytest.py
+++ b/pytest.py
@@ -157,6 +157,11 @@ def replace_trace(trace=None):
     try:
         yield
     finally:
+        # specific hack to work around a bug in pycoverage, see
+        # https://bitbucket.org/ned/coveragepy/issue/123
+        if (oldtrace is not None and not callable(oldtrace) and
+            hasattr(oldtrace, 'pytrace')):
+            oldtrace = oldtrace.pytrace
         sys.settrace(oldtrace)