Avoid deadlock when writing/reading data on a connecting TCP socket

TCP status polling is always performed as non blocking.
Trying to put a packet on a connecting socket will fail immediately.

(cherry picked from commit fa0cb7da0e096e01476eabef37c225404c7f6f26)

drivers/unix/stream_peer_tcp_posix.cpp

@@ -88,15 +88,10 @@ Error StreamPeerTCPPosix::_block(int p_sockfd, bool p_read, bool p_write) const
 	return ret < 0 ? FAILED : OK;
 };
 
-Error StreamPeerTCPPosix::_poll_connection(bool p_block) const {
+Error StreamPeerTCPPosix::_poll_connection() const {
 
 	ERR_FAIL_COND_V(status != STATUS_CONNECTING || sockfd == -1, FAILED);
 
-	if (p_block) {
-
-		_block(sockfd, false, true);
-	};
-
 	struct sockaddr_storage their_addr;
 	size_t addr_size = _set_sockaddr(&their_addr, peer_host, peer_port, sock_type);
 
@@ -191,7 +186,7 @@ Error StreamPeerTCPPosix::write(const uint8_t *p_data, int p_bytes, int &r_sent,
 
 	if (status != STATUS_CONNECTED) {
 
-		if (_poll_connection(p_block) != OK) {
+		if (_poll_connection() != OK) {
 
 			return FAILED;
 		};
@@ -251,7 +246,7 @@ Error StreamPeerTCPPosix::read(uint8_t *p_buffer, int p_bytes, int &r_received,
 
 	if (status == STATUS_CONNECTING) {
 
-		if (_poll_connection(p_block) != OK) {
+		if (_poll_connection() != OK) {
 
 			return FAILED;
 		};
@@ -330,7 +325,7 @@ bool StreamPeerTCPPosix::is_connected() const {
 StreamPeerTCP::Status StreamPeerTCPPosix::get_status() const {
 
 	if (status == STATUS_CONNECTING) {
-		_poll_connection(false);
+		_poll_connection();
 	};
 
 	return status;

drivers/unix/stream_peer_tcp_posix.h

@@ -45,7 +45,7 @@ protected:
 
 	Error _block(int p_sockfd, bool p_read, bool p_write) const;
 
-	Error _poll_connection(bool p_block) const;
+	Error _poll_connection() const;
 
 	IP_Address peer_host;
 	int peer_port;

platform/windows/stream_peer_winsock.cpp

@@ -77,15 +77,10 @@ Error StreamPeerWinsock::_block(int p_sockfd, bool p_read, bool p_write) const {
 	return ret < 0 ? FAILED : OK;
 };
 
-Error StreamPeerWinsock::_poll_connection(bool p_block) const {
+Error StreamPeerWinsock::_poll_connection() const {
 
 	ERR_FAIL_COND_V(status != STATUS_CONNECTING || sockfd == INVALID_SOCKET, FAILED);
 
-	if (p_block) {
-
-		_block(sockfd, false, true);
-	};
-
 	struct sockaddr_storage their_addr;
 	size_t addr_size = _set_sockaddr(&their_addr, peer_host, peer_port, sock_type);
 
@@ -121,7 +116,7 @@ Error StreamPeerWinsock::write(const uint8_t *p_data, int p_bytes, int &r_sent,
 
 	if (status != STATUS_CONNECTED) {
 
-		if (_poll_connection(p_block) != OK) {
+		if (_poll_connection() != OK) {
 
 			return FAILED;
 		};
@@ -179,7 +174,7 @@ Error StreamPeerWinsock::read(uint8_t *p_buffer, int p_bytes, int &r_received, b
 
 	if (status != STATUS_CONNECTED) {
 
-		if (_poll_connection(p_block) != OK) {
+		if (_poll_connection() != OK) {
 
 			return FAILED;
 		};
@@ -253,7 +248,7 @@ Error StreamPeerWinsock::get_partial_data(uint8_t *p_buffer, int p_bytes, int &r
 StreamPeerTCP::Status StreamPeerWinsock::get_status() const {
 
 	if (status == STATUS_CONNECTING) {
-		_poll_connection(false);
+		_poll_connection();
 	};
 
 	return status;

platform/windows/stream_peer_winsock.h

@@ -46,7 +46,7 @@ protected:
 
 	Error _block(int p_sockfd, bool p_read, bool p_write) const;
 
-	Error _poll_connection(bool p_block) const;
+	Error _poll_connection() const;
 
 	IP_Address peer_host;
 	int peer_port;