changeset:   92811:d748a3503ad5
parent:      92810:be4debd9a82e
parent:      92809:86ba3bdfac15
user:        Antoine Pitrou <solipsis@pitrou.net>
date:        Sat Oct 04 22:17:26 2014 +0200
files:       Misc/ACKS Misc/NEWS
description:
Issue #21905: Avoid RuntimeError in pickle.whichmodule() when sys.modules is mutated while iterating.

Patch by Olivier Grisel.


diff -r be4debd9a82e -r d748a3503ad5 Lib/pickle.py
--- a/Lib/pickle.py	Sat Oct 04 22:16:14 2014 +0200
+++ b/Lib/pickle.py	Sat Oct 04 22:17:26 2014 +0200
@@ -280,7 +280,9 @@
     module_name = getattr(obj, '__module__', None)
     if module_name is not None:
         return module_name
-    for module_name, module in sys.modules.items():
+    # Protect the iteration by using a list copy of sys.modules against dynamic
+    # modules that trigger imports of other modules upon calls to getattr.
+    for module_name, module in list(sys.modules.items()):
         if module_name == '__main__' or module is None:
             continue
         try:
diff -r be4debd9a82e -r d748a3503ad5 Misc/ACKS
--- a/Misc/ACKS	Sat Oct 04 22:16:14 2014 +0200
+++ b/Misc/ACKS	Sat Oct 04 22:17:26 2014 +0200
@@ -498,6 +498,7 @@
 Grant Griffin
 Andrea Griffini
 Duncan Grisby
+Olivier Grisel
 Fabian Groffen
 Eric Groo
 Dag Gruneau
diff -r be4debd9a82e -r d748a3503ad5 Misc/NEWS
--- a/Misc/NEWS	Sat Oct 04 22:16:14 2014 +0200
+++ b/Misc/NEWS	Sat Oct 04 22:17:26 2014 +0200
@@ -162,6 +162,9 @@
 Library
 -------
 
+- Issue #21905: Avoid RuntimeError in pickle.whichmodule() when sys.modules
+  is mutated while iterating.  Patch by Olivier Grisel.
+
 - Issue #11271: concurrent.futures.Executor.map() now takes a *chunksize*
   argument to allow batching of tasks in child processes and improve
   performance of ProcessPoolExecutor.  Patch by Dan O'Reilly.