__file__ used to be always set to the .pyc (or .pyo) file, even if

that file in fact did not exist or at least was not used.  Change this
so that __file__ is *only* set to the .pyc/.pyo file when it actually
read the code object from it; otherwise __file__ is set to the .py
file.

Python/import.c

@@ -706,6 +706,7 @@ load_source_module(name, pathname, fp)
 		if (Py_VerboseFlag)
 			fprintf(stderr, "import %s # precompiled from %s\n",
 				name, cpathname);
+		pathname = cpathname;
 	}
 	else {
 		co = parse_source_module(pathname, fp);
@@ -716,7 +717,7 @@ load_source_module(name, pathname, fp)
 				name, pathname);
 		write_compiled_module(co, cpathname, mtime);
 	}
-	m = PyImport_ExecCodeModuleEx(name, (PyObject *)co, cpathname);
+	m = PyImport_ExecCodeModuleEx(name, (PyObject *)co, pathname);
 	Py_DECREF(co);
 
 	return m;