Convert Object::cast_to() to the static version

Currently we rely on some undefined behavior when Object->cast_to() gets
called with a Null pointer. This used to work fine with GCC < 6 but
newer versions of GCC remove all codepaths in which the this pointer is
Null. However, the non-static cast_to() was supposed to be null safe.

This patch makes cast_to() Null safe and removes the now redundant Null
checks where they existed.

It is explained in this article: https://www.viva64.com/en/b/0226/

1 files changed, 7 insertions, 7 deletions

diff --git a/scene/3d/physics_body.cpp b/scene/3d/physics_body.cpp
index 402cd6314b..a1bee9a0ed 100644
--- a/scene/3d/physics_body.cpp
+++ b/scene/3d/physics_body.cpp
@@ -116,7 +116,7 @@ bool PhysicsBody::get_collision_layer_bit(int p_bit) const {
 void PhysicsBody::add_collision_exception_with(Node *p_node) {
 
 	ERR_FAIL_NULL(p_node);
-	PhysicsBody *physics_body = p_node->cast_to<PhysicsBody>();
+	PhysicsBody *physics_body = Object::cast_to<PhysicsBody>(p_node);
 	if (!physics_body) {
 		ERR_EXPLAIN("Collision exception only works between two objects of PhysicsBody type");
 	}
@@ -127,7 +127,7 @@ void PhysicsBody::add_collision_exception_with(Node *p_node) {
 void PhysicsBody::remove_collision_exception_with(Node *p_node) {
 
 	ERR_FAIL_NULL(p_node);
-	PhysicsBody *physics_body = p_node->cast_to<PhysicsBody>();
+	PhysicsBody *physics_body = Object::cast_to<PhysicsBody>(p_node);
 	if (!physics_body) {
 		ERR_EXPLAIN("Collision exception only works between two objects of PhysicsBody type");
 	}
@@ -254,7 +254,7 @@ StaticBody::~StaticBody() {
 void RigidBody::_body_enter_tree(ObjectID p_id) {
 
 	Object *obj = ObjectDB::get_instance(p_id);
-	Node *node = obj ? obj->cast_to<Node>() : NULL;
+	Node *node = Object::cast_to<Node>(obj);
 	ERR_FAIL_COND(!node);
 
 	Map<ObjectID, BodyState>::Element *E = contact_monitor->body_map.find(p_id);
@@ -278,7 +278,7 @@ void RigidBody::_body_enter_tree(ObjectID p_id) {
 void RigidBody::_body_exit_tree(ObjectID p_id) {
 
 	Object *obj = ObjectDB::get_instance(p_id);
-	Node *node = obj ? obj->cast_to<Node>() : NULL;
+	Node *node = Object::cast_to<Node>(obj);
 	ERR_FAIL_COND(!node);
 	Map<ObjectID, BodyState>::Element *E = contact_monitor->body_map.find(p_id);
 	ERR_FAIL_COND(!E);
@@ -303,7 +303,7 @@ void RigidBody::_body_inout(int p_status, ObjectID p_instance, int p_body_shape,
 	ObjectID objid = p_instance;
 
 	Object *obj = ObjectDB::get_instance(objid);
-	Node *node = obj ? obj->cast_to<Node>() : NULL;
+	Node *node = Object::cast_to<Node>(obj);
 
 	Map<ObjectID, BodyState>::Element *E = contact_monitor->body_map.find(objid);
 
@@ -369,7 +369,7 @@ void RigidBody::_direct_state_changed(Object *p_state) {
 //eh.. fuck
 #ifdef DEBUG_ENABLED
 
-	state = p_state->cast_to<PhysicsDirectBodyState>();
+	state = Object::cast_to<PhysicsDirectBodyState>(p_state);
 #else
 	state = (PhysicsDirectBodyState *)p_state; //trust it
 #endif
@@ -1105,7 +1105,7 @@ Object *KinematicBody::get_collision_collider_shape(int p_collision) const {
 	ERR_FAIL_INDEX_V(p_collision, colliders.size(), NULL);
 	Object *collider = get_collision_collider(p_collision);
 	if (collider) {
-		CollisionObject *obj2d = collider->cast_to<CollisionObject>();
+		CollisionObject *obj2d = Object::cast_to<CollisionObject>(collider);
 		if (obj2d) {
 			uint32_t owner = shape_find_owner(colliders[p_collision].collider_shape);
 			return obj2d->shape_owner_get_owner(owner);