Better fix for T41464: Material Boundary bug in Freestyle.

The problem addressed here is that there was no mean to check if an iterator
points the last of the elements being iterated over.  Such checking is necessary
to reliably dereference the iterator (i.e., calling the operator*() method of the
underlying C++ iterator object).

Now Interface0DIterator and StrokeVertexIterator have an .at_last property
to check if an iterator points the last element.  Using this new API feature,
the present commit partly reverts the previous commit rBeb8964fb7f19 to
better address T41464.

Differential revision: https://developer.blender.org/D752

Author: flokkievids (Folkert de Vries)

Reviewed by: kjym3 (Tamito Kajiyama)

1 files changed, 15 insertions, 7 deletions

diff --git a/source/blender/freestyle/intern/python/Iterator/BPy_Interface0DIterator.cpp b/source/blender/freestyle/intern/python/Iterator/BPy_Interface0DIterator.cpp
index faf99e90111..fca4c979bbb 100644
--- a/source/blender/freestyle/intern/python/Iterator/BPy_Interface0DIterator.cpp
+++ b/source/blender/freestyle/intern/python/Iterator/BPy_Interface0DIterator.cpp
@@ -120,19 +120,14 @@ static PyObject *Interface0DIterator_iternext(BPy_Interface0DIterator *self)
 		self->if0D_it->decrement();
 	}
 	else {
-		if (self->if0D_it->isEnd()) {
+		if (self->if0D_it->atLast() || self->if0D_it->isEnd()) {
 			PyErr_SetNone(PyExc_StopIteration);
 			return NULL;
 		}
 		if (self->at_start)
 			self->at_start = false;
-		else {
+		else
 			self->if0D_it->increment();
-			if (self->if0D_it->isEnd()) {
-				PyErr_SetNone(PyExc_StopIteration);
-				return NULL;
-			}
-		}
 	}
 	Interface0D *if0D = self->if0D_it->operator->();
 	return Any_BPy_Interface0D_from_Interface0D(*if0D);
@@ -177,11 +172,24 @@ static PyObject *Interface0DIterator_u_get(BPy_Interface0DIterator *self, void *
 	return PyFloat_FromDouble(self->if0D_it->u());
 }
 
+PyDoc_STRVAR(Interface0DIterator_at_last_doc,
+"True if the interator points to the last valid element.\n"
+"For its counterpart (pointing to the first valid element), use it.is_begin.\n"
+"\n"
+":type: bool");
+
+static PyObject *Interface0DIterator_at_last_get(BPy_Interface0DIterator *self, void *UNUSED(closure))
+{
+	return PyBool_from_bool(self->if0D_it->atLast());
+}
+
 static PyGetSetDef BPy_Interface0DIterator_getseters[] = {
 	{(char *)"object", (getter)Interface0DIterator_object_get, (setter)NULL,
 	                   (char *)Interface0DIterator_object_doc, NULL},
 	{(char *)"t", (getter)Interface0DIterator_t_get, (setter)NULL, (char *)Interface0DIterator_t_doc, NULL},
 	{(char *)"u", (getter)Interface0DIterator_u_get, (setter)NULL, (char *)Interface0DIterator_u_doc, NULL},
+	{(char *)"at_last", (getter)Interface0DIterator_at_last_get, (setter)NULL,
+	                    (char *)Interface0DIterator_at_last_doc, NULL},
 	{NULL, NULL, NULL, NULL, NULL}  /* Sentinel */
 };