Merge branch 'master' into stable

tests/test_stl_binders.py

 # -*- coding: utf-8 -*-
 import pytest
 
-import env  # noqa: F401
+import env
 from pybind11_tests import stl_binders as m
 
 

tests/test_virtual_functions.cpp

@@ -174,6 +174,25 @@ struct DispatchIssue : Base {
     }
 };
 
+// An abstract adder class that uses visitor pattern to add two data
+// objects and send the result to the visitor functor
+struct AdderBase {
+    struct Data {};
+    using DataVisitor = std::function<void (const Data&)>;
+
+    virtual void operator()(const Data& first, const Data& second, const DataVisitor& visitor) const = 0;
+    virtual ~AdderBase() = default;
+    AdderBase() = default;
+    AdderBase(const AdderBase&) = delete;
+};
+
+struct Adder : AdderBase {
+    void operator()(const Data& first, const Data& second, const DataVisitor& visitor) const override {
+        PYBIND11_OVERRIDE_PURE_NAME(void, AdderBase, "__call__", operator(), first, second, visitor);
+    }
+};
+
+
 static void test_gil() {
     {
         py::gil_scoped_acquire lock;
@@ -295,6 +314,27 @@ TEST_SUBMODULE(virtual_functions, m) {
 
     m.def("dispatch_issue_go", [](const Base * b) { return b->dispatch(); });
 
+    // test_recursive_dispatch_issue
+    // #3357: Recursive dispatch fails to find python function override
+    pybind11::class_<AdderBase, Adder>(m, "Adder")
+        .def(pybind11::init<>())
+        .def("__call__", &AdderBase::operator());
+
+    pybind11::class_<AdderBase::Data>(m, "Data")
+        .def(pybind11::init<>());
+
+    m.def("add2", [](const AdderBase::Data& first, const AdderBase::Data& second,
+                     const AdderBase& adder, const AdderBase::DataVisitor& visitor) {
+        adder(first, second, visitor);
+    });
+
+    m.def("add3", [](const AdderBase::Data& first, const AdderBase::Data& second, const AdderBase::Data& third,
+                     const AdderBase& adder, const AdderBase::DataVisitor& visitor) {
+        adder(first, second, [&] (const AdderBase::Data& first_plus_second) {
+            adder(first_plus_second, third, visitor);
+        });
+    });
+
     // test_override_ref
     // #392/397: overriding reference-returning functions
     class OverrideTest {

tests/test_virtual_functions.py

@@ -257,6 +257,39 @@ def test_dispatch_issue(msg):
     assert m.dispatch_issue_go(b) == "Yay.."
 
 
+def test_recursive_dispatch_issue(msg):
+    """#3357: Recursive dispatch fails to find python function override"""
+
+    class Data(m.Data):
+        def __init__(self, value):
+            super(Data, self).__init__()
+            self.value = value
+
+    class Adder(m.Adder):
+        def __call__(self, first, second, visitor):
+            # lambda is a workaround, which adds extra frame to the
+            # current CPython thread. Removing lambda reveals the bug
+            # [https://github.com/pybind/pybind11/issues/3357]
+            (lambda: visitor(Data(first.value + second.value)))()
+
+    class StoreResultVisitor:
+        def __init__(self):
+            self.result = None
+
+        def __call__(self, data):
+            self.result = data.value
+
+    store = StoreResultVisitor()
+
+    m.add2(Data(1), Data(2), Adder(), store)
+    assert store.result == 3
+
+    # without lambda in Adder class, this function fails with
+    # RuntimeError: Tried to call pure virtual function "AdderBase::__call__"
+    m.add3(Data(1), Data(2), Data(3), Adder(), store)
+    assert store.result == 6
+
+
 def test_override_ref():
     """#392/397: overriding reference-returning functions"""
     o = m.OverrideTest("asdf")

tools/pybind11Common.cmake

@@ -20,6 +20,7 @@ Adds the following functions::
 #]======================================================]
 
 # CMake 3.10 has an include_guard command, but we can't use that yet
+# include_guard(global) (pre-CMake 3.10)
 if(TARGET pybind11::lto)
   return()
 endif()

tools/pybind11NewTools.cmake

@@ -5,6 +5,12 @@
 # All rights reserved. Use of this source code is governed by a
 # BSD-style license that can be found in the LICENSE file.
 
+if(CMAKE_VERSION VERSION_LESS 3.12)
+  message(FATAL_ERROR "You cannot use the new FindPython module with CMake < 3.12")
+endif()
+
+include_guard(GLOBAL)
+
 get_property(
   is_config
   TARGET pybind11::headers
@@ -16,10 +22,6 @@ else()
   set(_pybind11_quiet "")
 endif()
 
-if(CMAKE_VERSION VERSION_LESS 3.12)
-  message(FATAL_ERROR "You cannot use the new FindPython module with CMake < 3.12")
-endif()
-
 if(NOT Python_FOUND
    AND NOT Python3_FOUND
    AND NOT Python2_FOUND)

tools/pybind11Tools.cmake

@@ -5,6 +5,11 @@
 # All rights reserved. Use of this source code is governed by a
 # BSD-style license that can be found in the LICENSE file.
 
+# include_guard(global) (pre-CMake 3.10)
+if(TARGET pybind11::python_headers)
+  return()
+endif()
+
 # Built-in in CMake 3.5+
 include(CMakeParseArguments)
 
@@ -38,7 +43,7 @@ endif()
 
 # A user can set versions manually too
 set(Python_ADDITIONAL_VERSIONS
-    "3.10;3.9;3.8;3.7;3.6;3.5;3.4"
+    "3.11;3.10;3.9;3.8;3.7;3.6;3.5;3.4"
     CACHE INTERNAL "")
 
 list(APPEND CMAKE_MODULE_PATH "${CMAKE_CURRENT_LIST_DIR}")