Merge branch 'pybind:master' into master

include/pybind11/pybind11.h

@@ -1173,9 +1173,16 @@ public:
             py::module_ m3 = m2.def_submodule("subsub", "A submodule of 'example.sub'");
     \endrst */
     module_ def_submodule(const char *name, const char *doc = nullptr) {
-        std::string full_name
+        const char *this_name = PyModule_GetName(m_ptr);
-            = std::string(PyModule_GetName(m_ptr)) + std::string(".") + std::string(name);
+        if (this_name == nullptr) {
-        auto result = reinterpret_borrow<module_>(PyImport_AddModule(full_name.c_str()));
+            throw error_already_set();
+        }
+        std::string full_name = std::string(this_name) + '.' + name;
+        handle submodule = PyImport_AddModule(full_name.c_str());
+        if (!submodule) {
+            throw error_already_set();
+        }
+        auto result = reinterpret_borrow<module_>(submodule);
         if (doc && options::show_user_defined_docstrings()) {
             result.attr("__doc__") = pybind11::str(doc);
         }
@@ -2326,7 +2333,7 @@ template <typename Access,
           typename Sentinel,
           typename ValueType,
           typename... Extra>
-iterator make_iterator_impl(Iterator first, Sentinel last, Extra &&...extra) {
+iterator make_iterator_impl(Iterator &&first, Sentinel &&last, Extra &&...extra) {
     using state = detail::iterator_state<Access, Policy, Iterator, Sentinel, ValueType, Extra...>;
     // TODO: state captures only the types of Extra, not the values
 
@@ -2352,7 +2359,7 @@ iterator make_iterator_impl(Iterator first, Sentinel last, Extra &&...extra) {
                 Policy);
     }
 
-    return cast(state{first, last, true});
+    return cast(state{std::forward<Iterator>(first), std::forward<Sentinel>(last), true});
 }
 
 PYBIND11_NAMESPACE_END(detail)
@@ -2363,13 +2370,15 @@ template <return_value_policy Policy = return_value_policy::reference_internal,
           typename Sentinel,
           typename ValueType = typename detail::iterator_access<Iterator>::result_type,
           typename... Extra>
-iterator make_iterator(Iterator first, Sentinel last, Extra &&...extra) {
+iterator make_iterator(Iterator &&first, Sentinel &&last, Extra &&...extra) {
     return detail::make_iterator_impl<detail::iterator_access<Iterator>,
                                       Policy,
                                       Iterator,
                                       Sentinel,
                                       ValueType,
-                                      Extra...>(first, last, std::forward<Extra>(extra)...);
+                                      Extra...>(std::forward<Iterator>(first),
+                                                std::forward<Sentinel>(last),
+                                                std::forward<Extra>(extra)...);
 }
 
 /// Makes a python iterator over the keys (`.first`) of a iterator over pairs from a
@@ -2379,13 +2388,15 @@ template <return_value_policy Policy = return_value_policy::reference_internal,
           typename Sentinel,
           typename KeyType = typename detail::iterator_key_access<Iterator>::result_type,
           typename... Extra>
-iterator make_key_iterator(Iterator first, Sentinel last, Extra &&...extra) {
+iterator make_key_iterator(Iterator &&first, Sentinel &&last, Extra &&...extra) {
     return detail::make_iterator_impl<detail::iterator_key_access<Iterator>,
                                       Policy,
                                       Iterator,
                                       Sentinel,
                                       KeyType,
-                                      Extra...>(first, last, std::forward<Extra>(extra)...);
+                                      Extra...>(std::forward<Iterator>(first),
+                                                std::forward<Sentinel>(last),
+                                                std::forward<Extra>(extra)...);
 }
 
 /// Makes a python iterator over the values (`.second`) of a iterator over pairs from a
@@ -2395,13 +2406,15 @@ template <return_value_policy Policy = return_value_policy::reference_internal,
           typename Sentinel,
           typename ValueType = typename detail::iterator_value_access<Iterator>::result_type,
           typename... Extra>
-iterator make_value_iterator(Iterator first, Sentinel last, Extra &&...extra) {
+iterator make_value_iterator(Iterator &&first, Sentinel &&last, Extra &&...extra) {
     return detail::make_iterator_impl<detail::iterator_value_access<Iterator>,
                                       Policy,
                                       Iterator,
                                       Sentinel,
                                       ValueType,
-                                      Extra...>(first, last, std::forward<Extra>(extra)...);
+                                      Extra...>(std::forward<Iterator>(first),
+                                                std::forward<Sentinel>(last),
+                                                std::forward<Extra>(extra)...);
 }
 
 /// Makes an iterator over values of an stl container or other container supporting
@@ -2460,7 +2473,7 @@ void implicitly_convertible() {
     };
 
     if (auto *tinfo = detail::get_type_info(typeid(OutputType))) {
-        tinfo->implicit_conversions.push_back(implicit_caster);
+        tinfo->implicit_conversions.emplace_back(std::move(implicit_caster));
     } else {
         pybind11_fail("implicitly_convertible: Unable to find type " + type_id<OutputType>());
     }

tests/test_modules.cpp

@@ -120,4 +120,6 @@ TEST_SUBMODULE(modules, m) {
 
         return failures;
     });
+
+    m.def("def_submodule", [](py::module_ m, const char *name) { return m.def_submodule(name); });
 }

tests/test_modules.py

@@ -1,3 +1,6 @@
+import pytest
+
+import env
 from pybind11_tests import ConstructorStats
 from pybind11_tests import modules as m
 from pybind11_tests.modules import subsubmodule as ms
@@ -89,3 +92,30 @@ def test_builtin_key_type():
         keys = __builtins__.__dict__.keys()
 
     assert {type(k) for k in keys} == {str}
+
+
+@pytest.mark.xfail("env.PYPY", reason="PyModule_GetName()")
+def test_def_submodule_failures():
+    sm = m.def_submodule(m, b"ScratchSubModuleName")  # Using bytes to show it works.
+    assert sm.__name__ == m.__name__ + "." + "ScratchSubModuleName"
+    malformed_utf8 = b"\x80"
+    if env.PYPY:
+        # It is not worth the effort finding a trigger for a failure when running with PyPy.
+        pytest.skip("Sufficiently exercised on platforms other than PyPy.")
+    else:
+        # Meant to trigger PyModule_GetName() failure:
+        sm_name_orig = sm.__name__
+        sm.__name__ = malformed_utf8
+        try:
+            with pytest.raises(Exception):
+                # Seen with Python 3.9: SystemError: nameless module
+                # But we do not want to exercise the internals of PyModule_GetName(), which could
+                # change in future versions of Python, but a bad __name__ is very likely to cause
+                # some kind of failure indefinitely.
+                m.def_submodule(sm, b"SubSubModuleName")
+        finally:
+            # Clean up to ensure nothing gets upset by a module with an invalid __name__.
+            sm.__name__ = sm_name_orig  # Purely precautionary.
+    # Meant to trigger PyImport_AddModule() failure:
+    with pytest.raises(UnicodeDecodeError):
+        m.def_submodule(sm, malformed_utf8)