Add ownership condition for finite PySequences

After the fix for PYSIDE-441,
another issue appeared related to QVariants and PySequences
PYSIDE-641, which was related due to the nature of this
python data type.

The problem had the same root cause,
using PySequences assuming they are always finite,
but not including the case of a class implementing
the __getitem__ method without a length.

The fix for PYSIDE-441 did not include the option
of having incomplete PySequences, so this change
add an extra condition to transfer the ownership
of a incomplete PySequence element.

Task-number: PYSIDE-671
Change-Id: I72ed1f5ea51c0c5b5a40ec51ab850732eea3c3b9
Reviewed-by: Christian Tismer <tismer@stackless.com>

1 files changed, 8 insertions, 1 deletions

diff --git a/sources/shiboken2/libshiboken/basewrapper.cpp b/sources/shiboken2/libshiboken/basewrapper.cpp
index b46fbaef2..ae6b2a68a 100644
--- a/sources/shiboken2/libshiboken/basewrapper.cpp
+++ b/sources/shiboken2/libshiboken/basewrapper.cpp
@@ -828,7 +828,14 @@ Py_hash_t hash(PyObject* pyObj)
 
 static void setSequenceOwnership(PyObject* pyObj, bool owner)
 {
-    if (PySequence_Check(pyObj)) {
+
+    bool has_length = true;
+    if (PySequence_Size(pyObj) < 0) {
+        PyErr_Clear();
+        has_length = false;
+    }
+
+    if (PySequence_Check(pyObj) && has_length) {
         Py_ssize_t size = PySequence_Size(pyObj);
         if (size > 0) {
             std::list<SbkObject*> objs = splitPyObject(pyObj);