[3.6] bpo-12239: Make GetProperty() return None for VT_EMPTY (GH-4539)

The previous behavior was to raise an exception

    NotImplementedError: result of type 0

when the value of the property is VT_EMPTY.

(cherry picked from commit 19fb134185ce155bc53f517116fca73093ba55e9)

1 files changed, 2 insertions, 0 deletions

diff --git a/PC/_msi.c b/PC/_msi.c
index 00755d6..a7c8fa3 100644
--- a/PC/_msi.c
+++ b/PC/_msi.c
@@ -578,6 +578,8 @@ summary_getproperty(msiobj* si, PyObject *args)
             if (sval != sbuf)
                 free(sval);
             return result;
+        case VT_EMPTY:
+            Py_RETURN_NONE;
     }
     PyErr_Format(PyExc_NotImplementedError, "result of type %d", type);
     return NULL;