[Python-checkins] bpo-34871: inspect: Don't pollute sys.modules (GH-9696)

[Miss Islington (bot)]

https://github.com/python/cpython/commit/6f85b826b527e240551613aeec3118a5469e3a33
commit: 6f85b826b527e240551613aeec3118a5469e3a33
branch: master
author: INADA Naoki <methane at users.noreply.github.com>
committer: Miss Islington (bot) <31488909+miss-islington at users.noreply.github.com>
date: 2018-10-04T09:47:09-07:00
summary:

bpo-34871: inspect: Don't pollute sys.modules (GH-9696)



https://bugs.python.org/issue34871

files:
A Misc/NEWS.d/next/Library/2018-10-04-18-46-54.bpo-34871.t3X-dB.rst
M Lib/inspect.py

diff --git a/Lib/inspect.py b/Lib/inspect.py
index 5b7f526939b6..857892bc8144 100644
--- a/Lib/inspect.py
+++ b/Lib/inspect.py
@@ -1988,7 +1988,7 @@ def _signature_fromstr(cls, obj, s, skip_bound_arg=True):
         module = sys.modules.get(module_name, None)
         if module:
             module_dict = module.__dict__
-    sys_module_dict = sys.modules
+    sys_module_dict = sys.modules.copy()
 
     def parse_name(node):
         assert isinstance(node, ast.arg)
diff --git a/Misc/NEWS.d/next/Library/2018-10-04-18-46-54.bpo-34871.t3X-dB.rst b/Misc/NEWS.d/next/Library/2018-10-04-18-46-54.bpo-34871.t3X-dB.rst
new file mode 100644
index 000000000000..8cff15671ce5
--- /dev/null
+++ b/Misc/NEWS.d/next/Library/2018-10-04-18-46-54.bpo-34871.t3X-dB.rst
@@ -0,0 +1,2 @@
+Fix inspect module polluted ``sys.modules`` when parsing
+``__text_signature__`` of callable.