Issue #16421: allow to load multiple modules from the same shared object.

Patch by Václav Šmilauer.

Author: asvetlov

Lib/test/test_imp.py

@@ -217,6 +217,20 @@ def test_issue15828_load_extensions(self):
         mod = imp.load_module(example, *x)
         self.assertEqual(mod.__name__, example)
 
+    def test_issue16421_multiple_modules_in_one_dll(self):
+        # Issue 16421: loading several modules from the same compiled file fails
+        m = '_testimportmultiple'
+        fileobj, pathname, description = imp.find_module(m)
+        fileobj.close()
+        mod0 = imp.load_dynamic(m, pathname)
+        mod1 = imp.load_dynamic('foo', pathname)
+        mod2 = imp.load_dynamic('bar', pathname)
+        self.assertEqual(mod0.__name__, m)
+        self.assertEqual(mod1.__name__, 'foo')
+        self.assertEqual(mod2.__name__, 'bar')
+        with self.assertRaises(ImportError):
+            imp.load_dynamic('nonexistent', pathname)
+
     def test_load_dynamic_ImportError_path(self):
         # Issue #1559549 added `name` and `path` attributes to ImportError
         # in order to provide better detail. Issue #10854 implemented those

Misc/ACKS

@@ -1109,6 +1109,7 @@ George Sipe
 J. Sipprell
 Kragen Sitaker
 Michael Sloan
+Václav Šmilauer
 Christopher Smith
 Eric V. Smith
 Gregory P. Smith

Misc/NEWS

@@ -10,6 +10,10 @@ What's New in Python 3.4.0 Alpha 1?
 Core and Builtins
 -----------------
 
+- Issue #16421: loading multiple modules from one shared object is now
+  handled correctly (previously, the first module loaded from that file
+  was silently returned). Patch by Václav Šmilauer.
+
 - Issue #16602: When a weakref's target was part of a long deallocation
   chain, the object could remain reachable through its weakref even though
   its refcount had dropped to zero.

Modules/_testimportmultiple.c

@@ -0,0 +1,57 @@
+/*
+ * C extensions module to test importing multiple modules from one compiled
+ * file (issue16421). This file defines 3 modules (_testimportmodule,
+ * foo, bar), only the first one is called the same as the compiled file.
+ */
+#include<Python.h>
+
+static struct PyModuleDef _testimportmultiple = {
+    PyModuleDef_HEAD_INIT,
+    "_testimportmultiple",
+    "_testimportmultiple doc",
+    -1,
+    NULL,
+    NULL,
+    NULL,
+    NULL,
+    NULL
+};
+
+PyMODINIT_FUNC PyInit__testimportmultiple()
+{
+    return PyModule_Create(&_testimportmultiple);
+}
+
+static struct PyModuleDef _foomodule = {
+    PyModuleDef_HEAD_INIT,
+    "foo",
+    "foo doc",
+    -1,
+    NULL,
+    NULL,
+    NULL,
+    NULL,
+    NULL
+};
+
+PyMODINIT_FUNC PyInit_foo()
+{
+    return PyModule_Create(&_foomodule);
+}
+
+static struct PyModuleDef _barmodule = {
+    PyModuleDef_HEAD_INIT,
+    "bar",
+    "bar doc",
+    -1,
+    NULL,
+    NULL,
+    NULL,
+    NULL,
+    NULL
+};
+
+PyMODINIT_FUNC PyInit_bar(){
+    return PyModule_Create(&_barmodule);
+}
+