From 65c17b8dea0c45bbcf3daf4463d2855d4d50ac5e Mon Sep 17 00:00:00 2001
From: Ovidiu Mircescu <ovidiu.mircescu@edf.fr>
Date: Tue, 26 Feb 2019 10:23:11 +0100
Subject: [PATCH] Deal with PyUnicode_AsUTF8 returning NULL.

According to https://docs.python.org/3/c-api/unicode.html#c.PyUnicode_AsUTF8
PyUnicode_AsUTF8String may return NULL in case of error.
---
 src/CMakeLists.txt      |  4 ++--
 src/Errors.cxx          | 14 +++++++++++---
 src/PyPtr.cxx           |  6 +++++-
 src/TypeConversions.cxx |  8 +++++++-
 4 files changed, 25 insertions(+), 7 deletions(-)

diff --git a/src/CMakeLists.txt b/src/CMakeLists.txt
index fbd6d76..08bfb17 100644
--- a/src/CMakeLists.txt
+++ b/src/CMakeLists.txt
@@ -50,8 +50,8 @@ TARGET_INCLUDE_DIRECTORIES(py2cpp PUBLIC
                           $<BUILD_INTERFACE:${CMAKE_CURRENT_SOURCE_DIR}/src>
                           $<INSTALL_INTERFACE:include>)
 
-INSTALL(TARGETS py2cpp EXPORT FindPy2cpp LIBRARY DESTINATION lib)
+INSTALL(TARGETS py2cpp EXPORT Py2cppCfg LIBRARY DESTINATION lib)
 INSTALL(FILES ${_py2cpp_headers} DESTINATION include/py2cpp)
-INSTALL(EXPORT FindPy2cpp DESTINATION lib/cmake/py2cpp)
+INSTALL(EXPORT Py2cppCfg DESTINATION lib/cmake/py2cpp FILE Py2cppConfig.cmake)
 
 ADD_SUBDIRECTORY(Test)
diff --git a/src/Errors.cxx b/src/Errors.cxx
index eb80814..f0984fc 100644
--- a/src/Errors.cxx
+++ b/src/Errors.cxx
@@ -31,7 +31,9 @@ std::string getLastPyError()
     PyErr_Fetch(&ptype, &pvalue, &ptraceback);
     PyErr_NormalizeException(&ptype, &pvalue, &ptraceback);
     pystr = PyObject_Str(pvalue);
-    result = std::string(PyUnicode_AsUTF8(pystr));
+    const char* charstr = PyUnicode_AsUTF8(pystr);
+    if(charstr != nullptr)
+      result = std::string(charstr);
     result += "\n";
     Py_DECREF(pystr);
     
@@ -54,7 +56,9 @@ std::string getLastPyError()
             for(int i=0; i<n; i++)
             {
               pystr = PyList_GetItem(pyList,i);
-              result += std::string(PyUnicode_AsUTF8(pystr));
+              const char* charstr = PyUnicode_AsUTF8(pystr);
+              if(charstr != nullptr)
+                result += charstr;
             }
             Py_DECREF(pyList);
           }
@@ -102,7 +106,11 @@ void ConversionCheck::addError(const std::string& expectedType, PyObject * obj)
     std::string pyRepr;
     PyObject* pyResult = PyObject_Repr(obj);
     if(pyResult && PyUnicode_Check(pyResult))
-      pyRepr = PyUnicode_AsUTF8(pyResult);
+    {
+      const char* charstr = PyUnicode_AsUTF8(pyResult);
+      if(charstr != nullptr)
+        pyRepr = charstr;
+    }
     else
       pyRepr = "unknown representation";
     Py_XDECREF(pyResult);
diff --git a/src/PyPtr.cxx b/src/PyPtr.cxx
index c5624bc..658c3d6 100644
--- a/src/PyPtr.cxx
+++ b/src/PyPtr.cxx
@@ -75,7 +75,11 @@ std::string PyPtr::repr()const
   {
     PyObject* pyResult = PyObject_Repr(thisObj);
     if(pyResult && PyUnicode_Check(pyResult))
-      result = PyUnicode_AsUTF8(pyResult);
+    {
+      const char* charstr = PyUnicode_AsUTF8(pyResult);
+      if(charstr != nullptr)
+        result = charstr;
+    }
     Py_XDECREF(pyResult);
   }
   return result;
diff --git a/src/TypeConversions.cxx b/src/TypeConversions.cxx
index d50b3a8..1f5a254 100644
--- a/src/TypeConversions.cxx
+++ b/src/TypeConversions.cxx
@@ -89,7 +89,13 @@ ConversionCheck fromPy(PyObject * po, std::string& result)
 {
   ConversionCheck check;
   if(po && PyUnicode_Check(po))
-    result = PyUnicode_AsUTF8(po);
+  {
+    const char* charstr = PyUnicode_AsUTF8(po);
+    if(charstr != nullptr)
+      result = charstr;
+    else
+      result = "";
+  }
   else
     check.addError("std::string", po);
   return check;
-- 
2.39.2