get_file() no longer leaks a FILE structure. If given a file descriptor, it...

get_file() no longer leaks a FILE structure.  If given a file descriptor, it calls dup() to get a new handle.  Then both the FILE object and the fd can be closed.
This is important, because otherwise, the leaked FILE object will be closed on process exit, causing assertions on Windows, e.g. in the test_multiprocessing.py regression test.

Python/import.c

@@ -3023,13 +3023,21 @@ get_file(char *pathname, PyObject *fob, char *mode)
 		int fd = PyObject_AsFileDescriptor(fob);
 		if (fd == -1)
 			return NULL;
-		/* XXX This will leak a FILE struct. Fix this!!!!
-		   (But it doesn't leak a file descrioptor!) */
+		if (!_PyVerify_fd(fd))
+			goto error;
+		/* the FILE struct gets a new fd, so that it can be closed
+		 * independently of the file descriptor given
+		 */
+		fd = dup(fd);
+		if (fd == -1)
+			goto error;
 		fp = fdopen(fd, mode);
 	}
-	if (fp == NULL)
-		PyErr_SetFromErrno(PyExc_IOError);
-	return fp;
+	if (fp)
+		return fp;
+error:
+	PyErr_SetFromErrno(PyExc_IOError);
+	return NULL;
 }
 
 static PyObject *
@@ -3051,8 +3059,7 @@ imp_load_compiled(PyObject *self, PyObject *args)
 		return NULL;
 	}
 	m = load_compiled_module(name, pathname, fp);
-	if (fob == NULL)
-		fclose(fp);
+	fclose(fp);
 	PyMem_Free(pathname);
 	return m;
 }
@@ -3081,6 +3088,8 @@ imp_load_dynamic(PyObject *self, PyObject *args)
 	}
 	m = _PyImport_LoadDynamicModule(name, pathname, fp);
 	PyMem_Free(pathname);
+	if (fp)
+		fclose(fp);
 	return m;
 }
 
@@ -3105,8 +3114,7 @@ imp_load_source(PyObject *self, PyObject *args)
 		return NULL;
 	}
 	m = load_source_module(name, pathname, fp);
-	if (fob == NULL)
-		fclose(fp);
+	fclose(fp);
 	return m;
 }
 
@@ -3150,6 +3158,8 @@ imp_load_module(PyObject *self, PyObject *args)
 	} 
 	ret = load_module(name, fp, pathname, type, NULL);
 	PyMem_Free(pathname);
+	if (fp)
+		fclose(fp);
 	return ret;
 }