Fixing first part of [#31760] Assignments not working properly for Object.dimensions

Problem was in fact that non-linear-contiguous axis assignement was broken (i.e. location.xy would work as expected, but location.xz would only affect .x part)... Now all possibilities should work fine.

Did not try to fix the problem specific to obj.dimension (when assigning multiple times to this array, only the last one is taken into account - in fact, a simple print() shows that assigning to dimension is not taken into account immediately), not sure whether this is normal behavior, or if we need a specific "update" of some kind for this prop?

1 files changed, 8 insertions, 1 deletions

diff --git a/source/blender/python/mathutils/mathutils_Vector.c b/source/blender/python/mathutils/mathutils_Vector.c
index 07bda4c2b91..54044b62e04 100644
--- a/source/blender/python/mathutils/mathutils_Vector.c
+++ b/source/blender/python/mathutils/mathutils_Vector.c
@@ -2268,6 +2268,11 @@ static int Vector_swizzle_set(VectorObject *self, PyObject *value, void *closure
 	axis_from = 0;
 	swizzleClosure = GET_INT_FROM_POINTER(closure);
 
+	/* We must first copy current vec into tvec, else some org values may be lost.
+	 * See [#31760].
+	 * Assuming self->size can't be higher than MAX_DIMENSIONS! */
+	memcpy(tvec, self->vec, self->size * sizeof(float));
+
 	while (swizzleClosure & SWIZZLE_VALID_AXIS) {
 		axis_to = swizzleClosure & SWIZZLE_AXIS;
 		tvec[axis_to] = vec_assign[axis_from];
@@ -2275,7 +2280,9 @@ static int Vector_swizzle_set(VectorObject *self, PyObject *value, void *closure
 		axis_from++;
 	}
 
-	memcpy(self->vec, tvec, axis_from * sizeof(float));
+	/* We must copy back the whole tvec into vec, else some changes may be lost (e.g. xz...).
+	 * See [#31760]. */
+	memcpy(self->vec, tvec, self->size * sizeof(float));
 	/* continue with BaseMathObject_WriteCallback at the end */
 
 	if (BaseMath_WriteCallback(self) == -1)