Fix recursive lazy imports and error path in bytecodes.c

Author: pablogsal

Include/internal/pycore_import.h

@@ -57,6 +57,7 @@ _PyImport_LazyImportModuleLevelObject(PyThreadState *tstate, PyObject *name, PyO
 #define IMPORTS_INIT \
     { \
         DLOPENFLAGS_INIT \
+        .lazy_import_resolution_depth = 0, \
         .find_and_load = { \
             .header = 1, \
         }, \

Include/internal/pycore_interp_structs.h

@@ -316,6 +316,8 @@ struct _import_state {
     PyObject *lazy_import_func;
     int lazy_imports_mode;
     PyObject *lazy_imports_filter;
+    /* Counter to prevent recursive lazy import creation */
+    int lazy_import_resolution_depth;
     /* The global import lock. */
     _PyRecursiveMutex lock;
     /* diagnostic info in PyImport_ImportModuleLevelObject() */

Python/bytecodes.c

@@ -1835,7 +1835,7 @@ dummy_func(
             PyObject *res_o = PyStackRef_AsPyObjectBorrow(*res);
             if (PyLazyImport_CheckExact(res_o)) {
                 PyObject *l_v = _PyImport_LoadLazyImportTstate(tstate, res_o);
-                if (PyDict_SetItem(GLOBALS(), name, l_v) < 0) {
+                if (l_v != NULL && PyDict_SetItem(GLOBALS(), name, l_v) < 0) {
                     JUMP_TO_LABEL(error);
                 }
                 res_o = l_v;

Python/executor_cases.c.h

@@ -3738,6 +3738,10 @@ _PyImport_LoadLazyImportTstate(PyThreadState *tstate, PyObject *lazy_import)
 
     PyObject *globals = PyEval_GetGlobals();
 
+    // Increment counter to prevent recursive lazy import creation
+    PyInterpreterState *interp = tstate->interp;
+    interp->imports.lazy_import_resolution_depth++;
+
     if (full) {
         obj = _PyEval_ImportNameWithImport(tstate,
                                    lz->lz_import_func,
@@ -3749,6 +3753,7 @@ _PyImport_LoadLazyImportTstate(PyThreadState *tstate, PyObject *lazy_import)
     } else {
         PyObject *name = PyUnicode_Substring(lz->lz_from, 0, dot);
         if (name == NULL) {
+            interp->imports.lazy_import_resolution_depth--;
             goto error;
         }
         obj = _PyEval_ImportNameWithImport(tstate,
@@ -3761,6 +3766,9 @@ _PyImport_LoadLazyImportTstate(PyThreadState *tstate, PyObject *lazy_import)
         Py_DECREF(name);
     }
 
+    // Decrement counter
+    interp->imports.lazy_import_resolution_depth--;
+
     if (obj == NULL) {
         goto error;
     }
@@ -3942,7 +3950,8 @@ PyImport_ImportModuleLevelObject(PyObject *name, PyObject *globals,
         goto error;
     }
 
-    if (globals != NULL &&
+    // Only check __lazy_modules__ if we're not already resolving a lazy import
+    if (interp->imports.lazy_import_resolution_depth == 0 && globals != NULL &&
         PyMapping_GetOptionalItem(globals, &_Py_ID(__lazy_modules__), &lazy_modules) < 0) {
         goto error;
     }
@@ -3965,7 +3974,7 @@ PyImport_ImportModuleLevelObject(PyObject *name, PyObject *globals,
         goto error;
     }
 
-    if (lazy_modules != NULL) {
+    if (interp->imports.lazy_import_resolution_depth == 0 && lazy_modules != NULL) {
         // Check and see if the module is opting in w/o syntax for backwards compatibility
         // with older Python versions.
         int contains = PySequence_Contains(lazy_modules, name);
@@ -3988,7 +3997,7 @@ PyImport_ImportModuleLevelObject(PyObject *name, PyObject *globals,
                 return NULL;
             }
 
-            final_mod = _PyImport_LazyImportModuleLevelObject(tstate, name, import_func, globals, 
+            final_mod = _PyImport_LazyImportModuleLevelObject(tstate, name, import_func, globals,
                                                               locals, fromlist, level);
             Py_DECREF(import_func);
             goto error;