Hack as a hot fix for Bullet's collision margin issue

(cherry picked from commit b3210c5cd6)

scene/3d/physics_body.cpp

@@ -962,8 +962,13 @@ Ref<KinematicCollision> KinematicBody::_move(const Vector3 &p_motion, bool p_inf
 
 	bool collided = move_and_collide(p_motion, p_infinite_inertia, col, p_exclude_raycast_shapes, p_test_only);
 
+	// Ugly hack as a hot fix, 65b3200 fix an issue but cause a problem with Bullet that broke games using Bullet.
+	// The bug is something internal to Bullet, seems to be related to the Bullet’s margin. As not proper fix was found yet,
+	// this temporary solution solves the issue for games using Bullet.
+	bool is_bullet = PhysicsServerManager::current_server_id != 0;
+
 	// Don't report collision when the whole motion is done.
-	if (collided && col.collision_safe_fraction < 1) {
+	if (collided && (col.collision_safe_fraction < 1 || is_bullet)) {
 		// Create a new instance when the cached reference is invalid or still in use in script.
 		if (motion_cache.is_null() || motion_cache->reference_get_count() > 1) {
 			motion_cache.instance();

servers/physics_server.cpp

@@ -810,6 +810,7 @@ PhysicsServer::~PhysicsServer() {
 
 Vector<PhysicsServerManager::ClassInfo> PhysicsServerManager::physics_servers;
 int PhysicsServerManager::default_server_id = -1;
+int PhysicsServerManager::current_server_id = -1;
 int PhysicsServerManager::default_server_priority = -1;
 const String PhysicsServerManager::setting_property_name(PNAME("physics/3d/physics_engine"));
 
@@ -857,6 +858,7 @@ String PhysicsServerManager::get_server_name(int p_id) {
 
 PhysicsServer *PhysicsServerManager::new_default_server() {
 	ERR_FAIL_COND_V(default_server_id == -1, nullptr);
+	current_server_id = default_server_id;
 	return physics_servers[default_server_id].create_callback();
 }
 
@@ -865,6 +867,7 @@ PhysicsServer *PhysicsServerManager::new_server(const String &p_name) {
 	if (id == -1) {
 		return nullptr;
 	} else {
+		current_server_id = id;
 		return physics_servers[id].create_callback();
 	}
 }

servers/physics_server.h

@@ -807,6 +807,7 @@ class PhysicsServerManager {
 
 public:
 	static const String setting_property_name;
+	static int current_server_id;
 
 private:
 	static void on_servers_changed();