From fae9f1b52f7dcbba3ee751cb4add4560620bebd1 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Mika=C3=ABl=20Capelle?= <capelle.mikael@gmail.com>
Date: Sat, 16 May 2020 17:37:41 +0200
Subject: [PATCH] Allow None value from python in functor converter.

---
 src/runner/converters.h | 17 +++++++++++++++--
 1 file changed, 15 insertions(+), 2 deletions(-)

diff --git a/src/runner/converters.h b/src/runner/converters.h
index b5fe206..9eba894 100644
--- a/src/runner/converters.h
+++ b/src/runner/converters.h
@@ -368,6 +368,12 @@ namespace utils {
 
     static void* convertible(PyObject* object)
     {
+      // We allow None here, we will just default-construct a std::function:
+      if (object == Py_None) {
+        return object;
+      }
+
+      // Otherwize we check that we have a callable object:
       if (!PyCallable_Check(object) || !has_arity(object, sizeof...(PARAMS))) {
         return nullptr;
       }
@@ -377,12 +383,19 @@ namespace utils {
     static void construct(PyObject* object, bpy::converter::rvalue_from_python_stage1_data* data)
     {
       bpy::object callable(bpy::handle<>(bpy::borrowed(object)));
-      void* storage = ((bpy::converter::rvalue_from_python_storage<std::function<RET(PARAMS...)>>*)data)->storage.bytes;
-      new (storage) std::function<RET(PARAMS...)>(FunctorWrapper(callable));
+      void* storage =((bpy::converter::rvalue_from_python_storage<std::function<RET(PARAMS...)>>*)data)->storage.bytes;
+      if (callable.is_none()) {
+        new (storage) std::function<RET(PARAMS...)>{};
+      }
+      else {
+        new (storage) std::function<RET(PARAMS...)>(FunctorWrapper(callable));
+      }
       data->convertible = storage;
     }
   };
 
+
+
   /**
    * @brief Call policy that automatically downcast shared pointer of type FromType
    * to shared pointer of type ToType.