Index: Modules/bz2module.c
===================================================================
--- Modules/bz2module.c	(révision 64756)
+++ Modules/bz2module.c	(copie de travail)
@@ -1451,6 +1451,7 @@
 	PyStringObject* ret;
 	ACQUIRE_LOCK(self);
 	if (self->mode == MODE_CLOSED) {
+		RELEASE_LOCK(self);
 		PyErr_SetString(PyExc_ValueError,
 				"I/O operation on closed file");
 		return NULL;