PyType_GetModuleByDef can return NULL without exception set

@ericsnowcurrently

The documentation does not mention that this is possible, but if the object passed in is not a heap type it returns NULL without setting an exception:

PyObject *
PyType_GetModuleByDef(PyTypeObject *type, PyModuleDef *def)
{
    assert(PyType_Check(type));   

    if (!_PyType_HasFeature(type, Py_TPFLAGS_HEAPTYPE)) {
        // type_ready_mro() ensures that no heap type is
        // contained in a static type MRO.
        return NULL;
    }
   ...
}

CC @ericsnowcurrently @encukou .

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gh-133166: Fix missing error emission of PyType_GetModuleByDef #133240

gh-133166: Fix missing error emission of PyType_GetModuleByDef (GH-13…

@neonene

Thanks for the catch, and thanks @neonene for the quick fix!

cpython/Objects/typeobject.c

Lines 5015 to 5020 in 90c786e

    
           PyType_GetModuleByDef(PyTypeObject *type, PyModuleDef *def) 
        
           { 
        
               PyObject *module = get_module_by_def(type, def); 
        
               if (module == NULL) { 
        
                   PyErr_Format( 
        
                       PyExc_TypeError,

3.13 has no issue. The test for 3.14 cannot be backported.

Ah! My mistake

Thank you for the report and the review.

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PyType_GetModuleByDef can return NULL without exception set #133166

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	PyType_GetModuleByDef(PyTypeObject type, PyModuleDef def)
	{
	PyObject *module = get_module_by_def(type, def);
	if (module == NULL) {
	PyErr_Format(
	PyExc_TypeError,

PyType_GetModuleByDef can return NULL without exception set #133166

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encukou commented on May 1, 2025

neonene commented on May 1, 2025

encukou commented on May 1, 2025

neonene commented on May 1, 2025

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