Zero initialize all pointer class and struct members

This prevents the pitfall of UB when checking if they have been
assigned something valid by comparing to nullptr.

core/config/engine.h

@@ -40,7 +40,7 @@ class Engine {
 public:
 	struct Singleton {
 		StringName name;
-		Object *ptr;
+		Object *ptr = nullptr;
 		StringName class_name; //used for binding generation hinting
 		bool user_created = false;
 		Singleton(const StringName &p_name = StringName(), Object *p_ptr = nullptr, const StringName &p_class_name = StringName());

core/core_bind.h

@@ -447,7 +447,7 @@ public:
 
 class Directory : public RefCounted {
 	GDCLASS(Directory, RefCounted);
-	DirAccess *d;
+	DirAccess *d = nullptr;
 
 	bool dir_open = false;
 	bool include_navigational = false;

core/io/file_access.h

@@ -183,7 +183,7 @@ struct FileAccessRef {
 
 	operator bool() const { return f != nullptr; }
 
-	FileAccess *f;
+	FileAccess *f = nullptr;
 
 	operator FileAccess *() { return f; }
 

core/io/file_access_pack.h

@@ -64,7 +64,7 @@ public:
 		uint64_t offset; //if offset is ZERO, the file was ERASED
 		uint64_t size;
 		uint8_t md5[16];
-		PackSource *src;
+		PackSource *src = nullptr;
 		bool encrypted;
 	};
 
@@ -103,7 +103,7 @@ private:
 
 	Vector<PackSource *> sources;
 
-	PackedDir *root;
+	PackedDir *root = nullptr;
 
 	static PackedData *singleton;
 	bool disabled = false;
@@ -150,7 +150,7 @@ class FileAccessPack : public FileAccess {
 	mutable bool eof;
 	uint64_t off;
 
-	FileAccess *f;
+	FileAccess *f = nullptr;
 	virtual Error _open(const String &p_path, int p_mode_flags);
 	virtual uint64_t _get_modified_time(const String &p_file) { return 0; }
 	virtual uint32_t _get_unix_permissions(const String &p_file) { return 0; }

core/io/ip.h

@@ -62,7 +62,7 @@ public:
 	typedef int ResolverID;
 
 private:
-	_IP_ResolverPrivate *resolver;
+	_IP_ResolverPrivate *resolver = nullptr;
 
 protected:
 	static IP *singleton;

core/io/resource_format_binary.h

@@ -127,7 +127,7 @@ class ResourceFormatSaverBinaryInstance {
 	bool skip_editor;
 	bool big_endian;
 	bool takeover_paths;
-	FileAccess *f;
+	FileAccess *f = nullptr;
 	String magic;
 	Set<RES> resource_set;
 

core/io/resource_uid.h

@@ -46,7 +46,7 @@ public:
 	static String get_cache_file();
 
 private:
-	void *crypto; // CryptoCore::RandomGenerator (avoid including crypto_core.h)
+	void *crypto = nullptr; // CryptoCore::RandomGenerator (avoid including crypto_core.h)
 	Mutex mutex;
 	struct Cache {
 		CharString cs;

core/io/udp_server.h

@@ -43,7 +43,7 @@ protected:
 	};
 
 	struct Peer {
-		PacketPeerUDP *peer;
+		PacketPeerUDP *peer = nullptr;
 		IPAddress ip;
 		uint16_t port = 0;
 

core/math/bvh.h

@@ -763,19 +763,19 @@ private:
 		tree._extra[p_handle.id()].last_updated_tick = 0;
 	}
 
-	PairCallback pair_callback;
-	UnpairCallback unpair_callback;
-	CheckPairCallback check_pair_callback;
-	void *pair_callback_userdata;
-	void *unpair_callback_userdata;
-	void *check_pair_callback_userdata;
+	PairCallback pair_callback = nullptr;
+	UnpairCallback unpair_callback = nullptr;
+	CheckPairCallback check_pair_callback = nullptr;
+	void *pair_callback_userdata = nullptr;
+	void *unpair_callback_userdata = nullptr;
+	void *check_pair_callback_userdata = nullptr;
 
 	BVHTREE_CLASS tree;
 
 	// for collision pairing,
 	// maintain a list of all items moved etc on each frame / tick
 	LocalVector<BVHHandle, uint32_t, true> changed_items;
-	uint32_t _tick;
+	uint32_t _tick = 1; // Start from 1 so items with 0 indicate never updated.
 
 	class BVHLockedFunction {
 	public:
@@ -801,23 +801,16 @@ private:
 		}
 
 	private:
-		Mutex *_mutex;
+		Mutex *_mutex = nullptr;
 	};
 
 	Mutex _mutex;
 
 	// local toggle for turning on and off thread safety in project settings
-	bool _thread_safe;
+	bool _thread_safe = BVH_THREAD_SAFE;
 
 public:
-	BVH_Manager() {
-		_tick = 1; // start from 1 so items with 0 indicate never updated
-		pair_callback = nullptr;
-		unpair_callback = nullptr;
-		pair_callback_userdata = nullptr;
-		unpair_callback_userdata = nullptr;
-		_thread_safe = BVH_THREAD_SAFE;
-	}
+	BVH_Manager() {}
 };
 
 #undef BVHTREE_CLASS

core/math/dynamic_bvh.h

@@ -183,7 +183,7 @@ private:
 		Node *parent = nullptr;
 		union {
 			Node *childs[2];
-			void *data;
+			void *data = nullptr;
 		};
 
 		_FORCE_INLINE_ bool is_leaf() const { return childs[1] == nullptr; }
@@ -215,10 +215,7 @@ private:
 			return axis.dot(volume.get_center() - org) <= 0;
 		}
 
-		Node() {
-			childs[0] = nullptr;
-			childs[1] = nullptr;
-		}
+		Node() {}
 	};
 
 	PagedAllocator<Node> node_allocator;

core/math/expression.h

@@ -147,7 +147,7 @@ private:
 		bool is_op = false;
 		union {
 			Variant::Operator op;
-			ENode *node;
+			ENode *node = nullptr;
 		};
 	};
 

core/math/octree.h

@@ -134,7 +134,7 @@ private:
 		List<PairData *, AL> pair_list;
 
 		struct OctantOwner {
-			Octant *octant;
+			Octant *octant = nullptr;
 			typename List<Element *, AL>::Element *E;
 		}; // an element can be in max 8 octants
 
@@ -147,7 +147,7 @@ private:
 		int refcount;
 		bool intersect;
 		Element *A, *B;
-		void *ud;
+		void *ud = nullptr;
 		typename List<PairData *, AL>::Element *eA, *eB;
 	};
 
@@ -156,18 +156,18 @@ private:
 	ElementMap element_map;
 	PairMap pair_map;
 
-	PairCallback pair_callback;
-	UnpairCallback unpair_callback;
-	void *pair_callback_userdata;
-	void *unpair_callback_userdata;
+	PairCallback pair_callback = nullptr;
+	UnpairCallback unpair_callback = nullptr;
+	void *pair_callback_userdata = nullptr;
+	void *unpair_callback_userdata = nullptr;
 
-	OctreeElementID last_element_id;
-	uint64_t pass;
+	OctreeElementID last_element_id = 1;
+	uint64_t pass = 1;
 
-	real_t unit_size;
-	Octant *root;
-	int octant_count;
-	int pair_count;
+	real_t unit_size = 1.0;
+	Octant *root = nullptr;
+	int octant_count = 0;
+	int pair_count = 0;
 
 	_FORCE_INLINE_ void _pair_check(PairData *p_pair) {
 		bool intersect = p_pair->A->aabb.intersects_inclusive(p_pair->B->aabb);
@@ -294,7 +294,7 @@ private:
 		const Vector3 *points;
 		int point_count;
 		T **result_array;
-		int *result_idx;
+		int *result_idx = nullptr;
 		int result_max;
 		uint32_t mask;
 	};
@@ -1265,18 +1265,7 @@ void Octree<T, use_pairs, AL>::set_unpair_callback(UnpairCallback p_callback, vo
 
 template <class T, bool use_pairs, class AL>
 Octree<T, use_pairs, AL>::Octree(real_t p_unit_size) {
-	last_element_id = 1;
-	pass = 1;
 	unit_size = p_unit_size;
-	root = nullptr;
-
-	octant_count = 0;
-	pair_count = 0;
-
-	pair_callback = nullptr;
-	unpair_callback = nullptr;
-	pair_callback_userdata = nullptr;
-	unpair_callback_userdata = nullptr;
 }
 
 #endif // OCTREE_H

core/object/callable_method_pointer.h

@@ -38,7 +38,7 @@
 #include "core/variant/callable.h"
 
 class CallableCustomMethodPointerBase : public CallableCustom {
-	uint32_t *comp_ptr;
+	uint32_t *comp_ptr = nullptr;
 	uint32_t comp_size;
 	uint32_t h;
 #ifdef DEBUG_METHODS_ENABLED

core/object/class_db.h

@@ -85,8 +85,8 @@ public:
 		int index;
 		StringName setter;
 		StringName getter;
-		MethodBind *_setptr;
-		MethodBind *_getptr;
+		MethodBind *_setptr = nullptr;
+		MethodBind *_getptr = nullptr;
 		Variant::Type type;
 	};
 

core/object/message_queue.h

@@ -62,10 +62,10 @@ class MessageQueue {
 		};
 	};
 
-	uint8_t *buffer;
+	uint8_t *buffer = nullptr;
 	uint32_t buffer_end = 0;
 	uint32_t buffer_max_used = 0;
-	uint32_t buffer_size;
+	uint32_t buffer_size = 0;
 
 	void _call_function(const Callable &p_callable, const Variant *p_args, int p_argcount, bool p_show_error);
 

core/object/object.h

@@ -538,8 +538,8 @@ private:
 
 	std::mutex _instance_binding_mutex;
 	struct InstanceBinding {
-		void *binding;
-		void *token;
+		void *binding = nullptr;
+		void *token = nullptr;
 		GDNativeInstanceBindingFreeCallback free_callback = nullptr;
 		GDNativeInstanceBindingReferenceCallback reference_callback = nullptr;
 	};
@@ -849,7 +849,7 @@ class ObjectDB {
 		uint64_t validator : OBJECTDB_VALIDATOR_BITS;
 		uint64_t next_free : OBJECTDB_SLOT_MAX_COUNT_BITS;
 		uint64_t is_ref_counted : 1;
-		Object *object;
+		Object *object = nullptr;
 	};
 
 	static SpinLock spin_lock;

core/object/script_language.h

@@ -430,11 +430,11 @@ public:
 extern uint8_t script_encryption_key[32];
 
 class PlaceHolderScriptInstance : public ScriptInstance {
-	Object *owner;
+	Object *owner = nullptr;
 	List<PropertyInfo> properties;
 	Map<StringName, Variant> values;
 	Map<StringName, Variant> constants;
-	ScriptLanguage *language;
+	ScriptLanguage *language = nullptr;
 	Ref<Script> script;
 
 public:

core/os/memory.h

@@ -186,9 +186,9 @@ void memdelete_arr(T *p_class) {
 
 struct _GlobalNil {
 	int color = 1;
-	_GlobalNil *right;
-	_GlobalNil *left;
-	_GlobalNil *parent;
+	_GlobalNil *right = nullptr;
+	_GlobalNil *left = nullptr;
+	_GlobalNil *parent = nullptr;
 
 	_GlobalNil();
 };

core/os/os.h

@@ -60,8 +60,6 @@ class OS {
 	bool _stdout_enabled = true;
 	bool _stderr_enabled = true;
 
-	char *last_error;
-
 	CompositeLogger *_logger = nullptr;
 
 	bool restart_on_exit = false;

core/os/pool_allocator.h

@@ -75,13 +75,13 @@ private:
 	typedef int EntryArrayPos;
 	typedef int EntryIndicesPos;
 
-	Entry *entry_array;
-	int *entry_indices;
+	Entry *entry_array = nullptr;
+	int *entry_indices = nullptr;
 	int entry_max;
 	int entry_count;
 
-	uint8_t *pool;
-	void *mem_ptr;
+	uint8_t *pool = nullptr;
+	void *mem_ptr = nullptr;
 	int pool_size;
 
 	int free_mem;

core/string/string_name.h

@@ -70,7 +70,7 @@ class StringName {
 	_Data *_data = nullptr;
 
 	union _HashUnion {
-		_Data *ptr;
+		_Data *ptr = nullptr;
 		uint32_t hash;
 	};
 

core/templates/command_queue_mt.h

@@ -311,7 +311,7 @@ class CommandQueueMT {
 	};
 
 	struct SyncCommand : public CommandBase {
-		SyncSemaphore *sync_sem;
+		SyncSemaphore *sync_sem = nullptr;
 
 		virtual void post() {
 			sync_sem->sem.post();

core/templates/map.h

@@ -178,7 +178,7 @@ public:
 private:
 	struct _Data {
 		Element *_root = nullptr;
-		Element *_nil;
+		Element *_nil = nullptr;
 		int size_cache = 0;
 
 		_FORCE_INLINE_ _Data() {
@@ -344,7 +344,7 @@ private:
 	void _insert_rb_fix(Element *p_new_node) {
 		Element *node = p_new_node;
 		Element *nparent = node->parent;
-		Element *ngrand_parent;
+		Element *ngrand_parent = nullptr;
 
 		while (nparent->color == RED) {
 			ngrand_parent = nparent->parent;
@@ -500,7 +500,7 @@ private:
 		Element *rp = ((p_node->left == _data._nil) || (p_node->right == _data._nil)) ? p_node : p_node->_next;
 		Element *node = (rp->left == _data._nil) ? rp->right : rp->left;
 
-		Element *sibling;
+		Element *sibling = nullptr;
 		if (rp == rp->parent->left) {
 			rp->parent->left = node;
 			sibling = rp->parent->right;

core/templates/oa_hash_map.h

@@ -306,7 +306,7 @@ public:
 		bool valid;
 
 		const TKey *key;
-		TValue *value;
+		TValue *value = nullptr;
 
 	private:
 		uint32_t pos;

core/templates/safe_list.h

@@ -75,8 +75,8 @@ public:
 	class Iterator {
 		friend class SafeList;
 
-		SafeListNode *cursor;
-		SafeList *list;
+		SafeListNode *cursor = nullptr;
+		SafeList *list = nullptr;
 
 		Iterator(SafeListNode *p_cursor, SafeList *p_list) :
 				cursor(p_cursor), list(p_list) {
@@ -253,8 +253,8 @@ public:
 	class Iterator {
 		friend class SafeList;
 
-		SafeListNode *cursor;
-		SafeList *list;
+		SafeListNode *cursor = nullptr;
+		SafeList *list = nullptr;
 
 	public:
 		Iterator(SafeListNode *p_cursor, SafeList *p_list) :

core/templates/self_list.h

@@ -108,7 +108,7 @@ public:
 
 private:
 	List *_root = nullptr;
-	T *_self;
+	T *_self = nullptr;
 	SelfList<T> *_next = nullptr;
 	SelfList<T> *_prev = nullptr;
 

core/templates/set.h

@@ -328,7 +328,7 @@ private:
 	void _insert_rb_fix(Element *p_new_node) {
 		Element *node = p_new_node;
 		Element *nparent = node->parent;
-		Element *ngrand_parent;
+		Element *ngrand_parent = nullptr;
 
 		while (nparent->color == RED) {
 			ngrand_parent = nparent->parent;
@@ -482,7 +482,7 @@ private:
 		Element *rp = ((p_node->left == _data._nil) || (p_node->right == _data._nil)) ? p_node : p_node->_next;
 		Element *node = (rp->left == _data._nil) ? rp->right : rp->left;
 
-		Element *sibling;
+		Element *sibling = nullptr;
 		if (rp == rp->parent->left) {
 			rp->parent->left = node;
 			sibling = rp->parent->right;

core/templates/thread_work_pool.h

@@ -68,7 +68,7 @@ class ThreadWorkPool {
 		Semaphore start;
 		Semaphore completed;
 		std::atomic<bool> exit;
-		BaseWork *work;
+		BaseWork *work = nullptr;
 	};
 
 	ThreadData *threads = nullptr;