8 files changed, 27 insertions, 12 deletions
diff --git a/core/bind/core_bind.cpp b/core/bind/core_bind.cpp
index 68650019a2..95f433607c 100644
--- a/core/bind/core_bind.cpp
+++ b/core/bind/core_bind.cpp
@@ -2773,8 +2773,9 @@ _Thread::_Thread() {
 
 _Thread::~_Thread() {
 
-	ERR_FAIL_COND_MSG(active, "Reference to a Thread object object was lost while the thread is still running...");
+	ERR_FAIL_COND_MSG(active, "Reference to a Thread object was lost while the thread is still running...");
 }
+
 /////////////////////////////////////
 
 PoolStringArray _ClassDB::get_class_list() const {
diff --git a/core/image.cpp b/core/image.cpp
index 672f850a1f..18d0653bae 100644
--- a/core/image.cpp
+++ b/core/image.cpp
@@ -2027,8 +2027,7 @@ Rect2 Image::get_used_rect() const {
 	for (int j = 0; j < height; j++) {
 		for (int i = 0; i < width; i++) {
 
-			bool opaque = get_pixel(i, j).a > 0.99;
-			if (!opaque)
+			if (!(get_pixel(i, j).a > 0))
 				continue;
 			if (i > maxx)
 				maxx = i;
diff --git a/core/io/multiplayer_api.cpp b/core/io/multiplayer_api.cpp
index 2708cb8c01..381ac4c0bb 100644
--- a/core/io/multiplayer_api.cpp
+++ b/core/io/multiplayer_api.cpp
@@ -111,6 +111,7 @@ void MultiplayerAPI::poll() {
 		Error err = network_peer->get_packet(&packet, len);
 		if (err != OK) {
 			ERR_PRINT("Error getting packet!");
+			break; // Something is wrong!
 		}
 
 		rpc_sender_id = sender;
diff --git a/core/io/pck_packer.cpp b/core/io/pck_packer.cpp
index 8bc73103e9..fb83f0ac90 100644
--- a/core/io/pck_packer.cpp
+++ b/core/io/pck_packer.cpp
@@ -63,6 +63,10 @@ void PCKPacker::_bind_methods() {
 
 Error PCKPacker::pck_start(const String &p_file, int p_alignment) {
 
+	if (file != NULL) {
+		memdelete(file);
+	}
+
 	file = FileAccess::open(p_file, FileAccess::WRITE);
 
 	ERR_FAIL_COND_V_MSG(!file, ERR_CANT_CREATE, "Can't open file to write: " + String(p_file) + ".");
diff --git a/core/io/xml_parser.cpp b/core/io/xml_parser.cpp
index 53e7da91a7..bd450dd84f 100644
--- a/core/io/xml_parser.cpp
+++ b/core/io/xml_parser.cpp
@@ -471,6 +471,10 @@ Error XMLParser::open_buffer(const Vector<uint8_t> &p_buffer) {
 
 	ERR_FAIL_COND_V(p_buffer.size() == 0, ERR_INVALID_DATA);
 
+	if (data) {
+		memdelete_arr(data);
+	}
+
 	length = p_buffer.size();
 	data = memnew_arr(char, length + 1);
 	copymem(data, p_buffer.ptr(), length);
@@ -489,6 +493,10 @@ Error XMLParser::open(const String &p_path) {
 	length = file->get_len();
 	ERR_FAIL_COND_V(length < 1, ERR_FILE_CORRUPT);
 
+	if (data) {
+		memdelete_arr(data);
+	}
+
 	data = memnew_arr(char, length + 1);
 	file->get_buffer((uint8_t *)data, length);
 	data[length] = 0;
diff --git a/core/io/zip_io.cpp b/core/io/zip_io.cpp
index 582b7c906b..40e902d874 100644
--- a/core/io/zip_io.cpp
+++ b/core/io/zip_io.cpp
@@ -97,6 +97,7 @@ int zipio_close(voidpf opaque, voidpf stream) {
 	FileAccess *&f = *(FileAccess **)opaque;
 	if (f) {
 		f->close();
+		memdelete(f);
 		f = NULL;
 	}
 	return 0;
diff --git a/core/object.cpp b/core/object.cpp
index 21666a334c..21a3b2cc6c 100644
--- a/core/object.cpp
+++ b/core/object.cpp
@@ -1213,9 +1213,9 @@ Error Object::emit_signal(const StringName &p_name, const Variant **p_args, int
 			MessageQueue::get_singleton()->push_call(target->get_instance_id(), c.method, args, argc, true);
 		} else {
 			Variant::CallError ce;
-			s->lock++;
+			_emitting = true;
 			target->call(c.method, args, argc, ce);
-			s->lock--;
+			_emitting = false;
 
 			if (ce.error != Variant::CallError::CALL_OK) {
 #ifdef DEBUG_ENABLED
@@ -1920,6 +1920,7 @@ Object::Object() {
 	_instance_id = ObjectDB::add_instance(this);
 	_can_translate = true;
 	_is_queued_for_deletion = false;
+	_emitting = false;
 	instance_binding_count = 0;
 	memset(_script_instance_bindings, 0, sizeof(void *) * MAX_SCRIPT_INSTANCE_BINDINGS);
 	script_instance = NULL;
@@ -1942,15 +1943,15 @@ Object::~Object() {
 
 	const StringName *S = NULL;
 
+	if (_emitting) {
+		//@todo this may need to actually reach the debugger prioritarily somehow because it may crash before
+		ERR_PRINTS("Object " + to_string() + " was freed or unreferenced while a signal is being emitted from it. Try connecting to the signal using 'CONNECT_DEFERRED' flag, or use queue_free() to free the object (if this object is a Node) to avoid this error and potential crashes.");
+	}
+
 	while ((S = signal_map.next(NULL))) {
 
 		Signal *s = &signal_map[*S];
 
-		if (s->lock > 0) {
-			//@todo this may need to actually reach the debugger prioritarily somehow because it may crash before
-			ERR_PRINTS("Object was freed or unreferenced while signal '" + String(*S) + "' is being emitted from it. Try connecting to the signal using 'CONNECT_DEFERRED' flag, or use queue_free() to free the object (if this object is a Node) to avoid this error and potential crashes.");
-		}
-
 		//brute force disconnect for performance
 		int slot_count = s->slot_map.size();
 		const VMap<Signal::Target, Signal::Slot>::Pair *slot_list = s->slot_map.get_array();
diff --git a/core/object.h b/core/object.h
index ad1865da7b..865c155764 100644
--- a/core/object.h
+++ b/core/object.h
@@ -465,8 +465,7 @@ private:
 
 		MethodInfo user;
 		VMap<Target, Slot> slot_map;
-		int lock;
-		Signal() { lock = 0; }
+		Signal() {}
 	};
 
 	HashMap<StringName, Signal> signal_map;
@@ -481,6 +480,7 @@ private:
 	bool _predelete();
 	void _postinitialize();
 	bool _can_translate;
+	bool _emitting;
 #ifdef TOOLS_ENABLED
 	bool _edited;
 	uint32_t _edited_version;