A deadlock could occur if you called conn_close() while the remote was sending

a buttload of data.  If the input queue filled up before the socket was closed,
the input queue could be stuck waiting for the ring buffer to drain while
conn_close() is stuck waiting for the input thread to stop.

We now consume data from the input buffer while waiting for the input thread
to stop.

src/syncterm/conn_pty.c

@@ -502,6 +502,7 @@ int pty_connect(struct bbslist *bbs)
 int pty_close(void)
 {
 	time_t	start;
+	char garbage[1024];
 
 	conn_api.terminate=1;
 	start=time(NULL);
@@ -515,8 +516,10 @@ int pty_close(void)
 	kill(child_pid, SIGKILL);
 	waitpid(child_pid, &status, 0);
 
-	while(conn_api.input_thread_running || conn_api.output_thread_running)
+	while(conn_api.input_thread_running || conn_api.output_thread_running) {
+		conn_recv_upto(garbage, sizeof(garbage), 0);
 		SLEEP(1);
+	}
 	destroy_conn_buf(&conn_inbuf);
 	destroy_conn_buf(&conn_outbuf);
 	FREE_AND_NULL(conn_api.rd_buf);

src/syncterm/conn_telnet.c

@@ -170,10 +170,14 @@ int telnet_connect(struct bbslist *bbs)
 
 int telnet_close(void)
 {
+	char	garbage[1024];
+
 	conn_api.terminate=1;
 	closesocket(telnet_sock);
-	while(conn_api.input_thread_running || conn_api.output_thread_running)
+	while(conn_api.input_thread_running || conn_api.output_thread_running) {
+		conn_recv_upto(garbage, sizeof(garbage), 0);
 		SLEEP(1);
+	}
 	destroy_conn_buf(&conn_inbuf);
 	destroy_conn_buf(&conn_outbuf);
 	FREE_AND_NULL(conn_api.rd_buf);

src/syncterm/modem.c

@@ -313,6 +313,7 @@ int serial_close(void)
 int modem_close(void)
 {
 	time_t start;
+	char garbage[1024];
 
 	conn_api.terminate=1;
 
@@ -333,8 +334,10 @@ int modem_close(void)
 	}
 
 CLOSEIT:
-	while(conn_api.input_thread_running || conn_api.output_thread_running)
+	while(conn_api.input_thread_running || conn_api.output_thread_running) {
+		conn_recv_upto(garbage, sizeof(garbage), 0);
 		SLEEP(1);
+	}
 	comClose(com);
 
 	destroy_conn_buf(&conn_inbuf);

src/syncterm/rlogin.c

@@ -174,10 +174,14 @@ int rlogin_connect(struct bbslist *bbs)
 
 int rlogin_close(void)
 {
+	char garbage[1024];
+
 	conn_api.terminate=1;
 	closesocket(sock);
-	while(conn_api.input_thread_running || conn_api.output_thread_running)
+	while(conn_api.input_thread_running || conn_api.output_thread_running) {
+		conn_recv_upto(garbage, sizeof(garbage), 0);
 		SLEEP(1);
+	}
 	destroy_conn_buf(&conn_inbuf);
 	destroy_conn_buf(&conn_outbuf);
 	FREE_AND_NULL(conn_api.rd_buf);

src/syncterm/ssh.c

@@ -295,11 +295,15 @@ int ssh_connect(struct bbslist *bbs)
 
 int ssh_close(void)
 {
+	char garbage[1024];
+
 	conn_api.terminate=1;
 	ssh_active=FALSE;
 	cl.SetAttribute(ssh_session, CRYPT_SESSINFO_ACTIVE, 0);
-	while(conn_api.input_thread_running || conn_api.output_thread_running)
+	while(conn_api.input_thread_running || conn_api.output_thread_running) {
+		conn_recv_upto(garbage, sizeof(garbage), 0);
 		SLEEP(1);
+	}
 	cl.DestroySession(ssh_session);
 	closesocket(sock);
 	sock=INVALID_SOCKET;

src/syncterm/syncterm.c

@@ -1612,6 +1612,8 @@ int main(int argc, char **argv)
 			last_bbs=strdup(bbs->name);
 		bbs=NULL;
 	}
+	if (last_bbs)
+		free(last_bbs);
 	// Save changed settings
 	if(getscaling() > 0 && getscaling() != settings.scaling_factor) {
 		char	inipath[MAX_PATH+1];