Fix scrollback wrap bug, add /clear, add TCP keepalive

- Fix off-by-one in redraw_window circular buffer indexing (<=  to <)
  that caused stale content after 500 lines filled
- Add /clear command to reset current window scrollback
- Add TCP keepalive and application-level ping timeout to detect
  dead connections

main.c

@@ -16,6 +16,7 @@
 #include <termios.h>
 #include <pwd.h>
 #include <signal.h>
+#include <netinet/tcp.h>
 
 #include "charset.h"
 
@@ -56,6 +57,8 @@ static size_t recv_len = 0;
 static char nick[64] = "kiro_user";
 static int term_rows = 24, term_cols = 80;
 static struct termios orig_term;
+static time_t last_recv = 0;   /* time of last data from server */
+static int ping_sent = 0;      /* we sent a client PING, awaiting reply */
 
 /* Per-window scrollback buffer */
 static struct {
@@ -81,6 +84,7 @@ static int translate_public = 0; /* /trans toggle: echo translations to channel
 static int translate_enabled = 1; /* master toggle for translation */
 static int irc_colors = 1; /* display IRC colour codes as ANSI */
 static char rent_msg[256] = "This space available for rent";
+static int log_enabled = 0;
 
 /* Track nicks who sent us private messages */
 #define MAX_PM_NICKS 32
@@ -191,6 +195,8 @@ static void ai_config_load(void)
 			irc_colors = atoi(eq);
 		else if (strcmp(line, "rent") == 0)
 			snprintf(rent_msg, sizeof(rent_msg), "%s", eq);
+		else if (strcmp(line, "log") == 0)
+			log_enabled = (strcmp(eq, "true") == 0 || atoi(eq));
 	}
 	fclose(f);
 
@@ -686,7 +692,7 @@ static void redraw_window(void)
 	while (start_pos > 0 && rows_used < visible) {
 		int li = start_pos - 1;
 		int buf_idx;
-		if (count <= SCROLLBACK)
+		if (count < SCROLLBACK)
 			buf_idx = li;
 		else
 			buf_idx = (win_buf[current_level].head - count + li + SCROLLBACK) % SCROLLBACK;
@@ -706,7 +712,7 @@ static void redraw_window(void)
 	for (int i = 0; i < show; i++) {
 		int li = start_pos + i;
 		int buf_idx;
-		if (count <= SCROLLBACK)
+		if (count < SCROLLBACK)
 			buf_idx = li;
 		else
 			buf_idx = (win_buf[current_level].head - count + li + SCROLLBACK) % SCROLLBACK;
@@ -821,6 +827,16 @@ static int irc_connect(const char *host, const char *port)
 	if (fd < 0)
 		die("connect");
 
+	/* Enable TCP keepalive to detect dead connections */
+	int one = 1;
+	setsockopt(fd, SOL_SOCKET, SO_KEEPALIVE, &one, sizeof(one));
+	int idle = 60;
+	setsockopt(fd, IPPROTO_TCP, TCP_KEEPIDLE, &idle, sizeof(idle));
+	int intvl = 15;
+	setsockopt(fd, IPPROTO_TCP, TCP_KEEPINTVL, &intvl, sizeof(intvl));
+	int cnt = 4;
+	setsockopt(fd, IPPROTO_TCP, TCP_KEEPCNT, &cnt, sizeof(cnt));
+
 	return fd;
 }
 
@@ -964,48 +980,12 @@ static FILE *logfp = NULL;
 
 static void log_raw(const char *line, size_t len)
 {
+	(void)len;
 	if (!logfp) return;
 	time_t now = time(NULL);
 	struct tm *tm = localtime(&now);
-	fprintf(logfp, "[%02d:%02d:%02d] len=%zu charset=",
-	        tm->tm_hour, tm->tm_min, tm->tm_sec, len);
-
-	/* Detect charset */
-	const unsigned char *u = (const unsigned char *)line;
-	int has_high = 0, valid_utf8 = 1;
-	for (size_t i = 0; i < len; i++) {
-		if (u[i] >= 0x80) {
-			has_high = 1;
-			if ((u[i] & 0xE0) == 0xC0) {
-				if (i+1 >= len || (u[i+1] & 0xC0) != 0x80)
-					valid_utf8 = 0;
-				else i += 1;
-			} else if ((u[i] & 0xF0) == 0xE0) {
-				if (i+2 >= len || (u[i+1] & 0xC0) != 0x80 ||
-				    (u[i+2] & 0xC0) != 0x80)
-					valid_utf8 = 0;
-				else i += 2;
-			} else if ((u[i] & 0xF8) == 0xF0) {
-				if (i+3 >= len || (u[i+1] & 0xC0) != 0x80 ||
-				    (u[i+2] & 0xC0) != 0x80 || (u[i+3] & 0xC0) != 0x80)
-					valid_utf8 = 0;
-				else i += 3;
-			} else {
-				valid_utf8 = 0;
-			}
-		}
-	}
-	if (!has_high)
-		fprintf(logfp, "ASCII");
-	else if (valid_utf8)
-		fprintf(logfp, "UTF-8");
-	else
-		fprintf(logfp, "ISO-8859-1");
-
-	fprintf(logfp, "\n  text: %s\n  hex: ", line);
-	for (size_t i = 0; i < len; i++)
-		fprintf(logfp, "%02X ", u[i]);
-	fprintf(logfp, "\n");
+	fprintf(logfp, "[%02d:%02d:%02d] %s\n",
+	        tm->tm_hour, tm->tm_min, tm->tm_sec, line);
 	fflush(logfp);
 }
 
@@ -1557,6 +1537,11 @@ static void handle_input(char *line)
 			exit(0);
 		} else if (strcasecmp(cmd, "raw") == 0 && args) {
 			irc_send_raw("%s", args);
+		} else if (strcasecmp(cmd, "clear") == 0) {
+			win_buf[current_level].count = 0;
+			win_buf[current_level].head = 0;
+			scroll_offset = 0;
+			redraw_window();
 		} else {
 			wprintf(current_level, "Unknown command: /%s\n", cmd);
 		}
@@ -1723,7 +1708,7 @@ int main(int argc, char *argv[])
 
 	ai_config_load();
 
-	logfp = fopen("irc.log", "a");
+	logfp = log_enabled ? fopen("irc.log", "a") : NULL;
 	if (logfp)
 		fprintf(logfp, "--- Session started ---\n");
 
@@ -1751,6 +1736,7 @@ int main(int argc, char *argv[])
 	wprintf(WL_STATUS, "Connecting to %s:%s as %s...\n", host, port, nick);
 
 	sock_fd = irc_connect(host, port);
+	last_recv = time(NULL);
 
 	wprintf(WL_STATUS, "Connected.\n");
 
@@ -1826,6 +1812,20 @@ int main(int argc, char *argv[])
 			}
 		}
 
+		/* Detect dead connection: no data for 240s → send PING,
+		   no reply after 60 more seconds → disconnect */
+		if (last_recv > 0) {
+			time_t elapsed = time(NULL) - last_recv;
+			if (!ping_sent && elapsed >= 240) {
+				irc_send_raw("PING :keepalive");
+				ping_sent = 1;
+			} else if (ping_sent && elapsed >= 300) {
+				wprintf(WL_STATUS,
+				        "* No response from server (timeout)\n");
+				break;
+			}
+		}
+
 		/* Check translation results */
 		for (int ti = 0; ti < translate_count; ) {
 			if (FD_ISSET(translate_pending[ti].fd, &fds)) {
@@ -1989,6 +1989,8 @@ int main(int argc, char *argv[])
 			}
 			recv_len += (size_t)n;
 			recv_buf[recv_len] = '\0';
+			last_recv = time(NULL);
+			ping_sent = 0;
 			process_recv();
 		}