Merge pull request #2249 from pfhayes/anydbmfix

Fix importing anydbm within pytest

AUTHORS

@@ -113,6 +113,7 @@ Nicolas Delaby
 Oleg Pidsadnyi
 Oliver Bestwalter
 Omar Kohl
+Patrick Hayes
 Pieter Mulder
 Piotr Banaszkiewicz
 Punyashloka Biswal

CHANGELOG.rst

@@ -1,6 +1,12 @@
 3.0.7 (unreleased)
 ==================
 
+
+* Fix issue in assertion rewriting breaking due to modules silently discarding
+  other modules when importing fails
+  Notably, importing the `anydbm` module is fixed. (`#2248`_).
+  Thanks `@pfhayes`_ for the PR.
+
 * junitxml: Fix problematic case where system-out tag occured twice per testcase
   element in the XML report. Thanks `@kkoukiou`_ for the PR.
 
@@ -30,12 +36,14 @@
 
 *
 
+.. _@pfhayes: https://github.com/pfhayes
 .. _@bluetech: https://github.com/bluetech
 .. _@gst: https://github.com/gst
 .. _@sirex: https://github.com/sirex
 .. _@vidartf: https://github.com/vidartf
 .. _@kkoukiou: https://github.com/KKoukiou
 
+.. _#2248: https://github.com/pytest-dev/pytest/issues/2248
 .. _#2137: https://github.com/pytest-dev/pytest/issues/2137
 .. _#2160: https://github.com/pytest-dev/pytest/issues/2160
 .. _#2231: https://github.com/pytest-dev/pytest/issues/2231

_pytest/assertion/rewrite.py

@@ -215,7 +215,8 @@ class AssertionRewritingHook(object):
             mod.__loader__ = self
             py.builtin.exec_(co, mod.__dict__)
         except:
-            del sys.modules[name]
+            if name in sys.modules:
+                del sys.modules[name]
             raise
         return sys.modules[name]