Port D70667959 and D70795133 to 3.12

Summary: This just ports this missing change over to 3.12. The test failures are related to  D79649298.

Reviewed By: itamaro

Differential Revision: D79590225

fbshipit-source-id: 4ad15d3cfd5e356177a4213960748da91e58a0b9

Author: DinoV

Python/import.c

@@ -3034,6 +3034,18 @@ add_lazy_modules(PyThreadState *tstate, PyObject *builtins, PyObject *name, PyOb
                 if (res < 0) {
                     goto error;
                 } else if (!res) {
+                    PyObject *existing = import_get_module(tstate, name);
+                    Py_XDECREF(existing);
+                    if (existing != NULL && _PyDict_GetItemKeepLazy(parent_dict, child) != NULL) {
+                        // If the module is already loaded we don't need to do the below, we should
+                        // have already recorded the module as a lazy module.  Even if we've loaded
+                        // the module previously we may return 1 (meaning load lazily), but that's
+                        // because we want to continue processing the names in the fromlist lazily.
+                        // If we return 0 (meaning load eagerly) we'll end up loading the fromlist
+                        // eagerly too.
+                        goto end;
+                    }
+
                     PyObject *lazy_module_attr = _PyLazyImport_New(builtins, parent, child);
                     if (lazy_module_attr == NULL) {
                         goto error;