bpo-29587: Update gen.throw() to chain exceptions (#19823)
Before this commit, if an exception was active inside a generator
when calling gen.throw(), that exception was lost (i.e. there was
no implicit exception chaining). This commit fixes that by
setting exc.__context__ when calling gen.throw(exc).
diff --git a/Objects/genobject.c b/Objects/genobject.c
index 6e36690..41a63ae 100644
--- a/Objects/genobject.c
+++ b/Objects/genobject.c
@@ -512,6 +512,15 @@
}
PyErr_Restore(typ, val, tb);
+ /* XXX Should we also handle the case where exc_type is true and
+ exc_value is false? */
+ if (gen->gi_exc_state.exc_type && gen->gi_exc_state.exc_value) {
+ Py_INCREF(gen->gi_exc_state.exc_type);
+ Py_INCREF(gen->gi_exc_state.exc_value);
+ Py_XINCREF(gen->gi_exc_state.exc_traceback);
+ _PyErr_ChainExceptions(gen->gi_exc_state.exc_type,
+ gen->gi_exc_state.exc_value, gen->gi_exc_state.exc_traceback);
+ }
return gen_send_ex(gen, Py_None, 1, 0);
failed_throw: