Handle snprintf() returning -1.

MFC after:	2 weeks

usr.bin/apply/apply.c

@@ -143,13 +143,13 @@ main(int argc, char *argv[]) {
 
 		p = cmd;
 		offset = snprintf(cmd, cmdsize, EXEC "%s", argv[0]);
-		if ((size_t)offset >= cmdsize)
+		if (offset < 0 || (size_t)offset >= cmdsize)
 			err(1, "snprintf() failed");
 		p += offset;
 		cmdsize -= offset;
 		for (i = 1; i <= nargs; i++) {
 			offset = snprintf(p, cmdsize, " %c%d", magic, i);
-			if ((size_t)offset >= cmdsize)
+			if (offset < 0 || (size_t)offset >= cmdsize)
 				err(1, "snprintf() failed");
 			p += offset;
 			cmdsize -= offset;
@@ -163,7 +163,7 @@ main(int argc, char *argv[]) {
 			nargs = 1;
 	} else {
 		offset = snprintf(cmd, cmdsize, EXEC "%s", argv[0]);
-		if ((size_t)offset >= cmdsize)
+		if (offset < 0 || (size_t)offset >= cmdsize)
 			err(1, "snprintf() failed");
 		nargs = n;
 	}
@@ -196,7 +196,7 @@ main(int argc, char *argv[]) {
 			if (p[0] == magic && isdigit(p[1]) && p[1] != '0') {
 				offset = snprintf(q, l, "%s",
 				    argv[(++p)[0] - '0']);
-				if ((size_t)offset >= l)
+				if (offset < 0 || (size_t)offset >= l)
 					err(1, "snprintf() failed");
 				q += offset;
 				l -= offset;

usr.bin/ftp/fetch.c

@@ -282,7 +282,7 @@ url_get(origline, proxyenv)
 		printf("Requesting %s (via %s)\n", origline, proxyenv);
 	len = snprintf(buf, sizeof(buf), "GET %s%s HTTP/1.0\r\n\r\n",
 	    proxy ? "" : "/", path);
-	if (write(s, buf, len) < len) {
+	if (len < 0 || write(s, buf, len) < len) {
 		warn("Writing HTTP request");
 		goto cleanup_url_get;
 	}

usr.bin/ftp/util.c

@@ -604,7 +604,7 @@ progressmeter(flag)
 	struct timeval now, td, wait;
 	off_t cursize, abbrevsize;
 	double elapsed;
-	int ratio, barlength, i, len;
+	int ratio, barlength, i, len, n;
 	off_t remaining;
 	char buf[256];
 
@@ -623,16 +623,20 @@ progressmeter(flag)
 	ratio = cursize * 100 / filesize;
 	ratio = MAX(ratio, 0);
 	ratio = MIN(ratio, 100);
-	len += snprintf(buf + len, sizeof(buf) - len, "\r%3d%% ", ratio);
+	n = snprintf(buf + len, sizeof(buf) - len, "\r%3d%% ", ratio);
+	if (n > 0)
+		len += n;
 
 	barlength = ttywidth - 30;
 	if (barlength > 0) {
 		i = barlength * ratio / 100;
-		len += snprintf(buf + len, sizeof(buf) - len,
+		n = snprintf(buf + len, sizeof(buf) - len,
 		    "|%.*s%*s|", i, 
 "*****************************************************************************"
 "*****************************************************************************",
 		    barlength - i, "");
+		if (n > 0)
+			len += n;
 	}
 
 	i = 0;
@@ -641,9 +645,11 @@ progressmeter(flag)
 		i++;
 		abbrevsize >>= 10;
 	}
-	len += snprintf(buf + len, sizeof(buf) - len,
+	n = snprintf(buf + len, sizeof(buf) - len,
 	    " %5qd %c%c ", (long long)abbrevsize, prefixes[i],
 	    prefixes[i] == ' ' ? ' ' : 'B');
+	if (n > 0)
+		len += n;
 
 	timersub(&now, &lastupdate, &wait);
 	if (cursize > lastsize) {
@@ -660,30 +666,34 @@ progressmeter(flag)
 	elapsed = td.tv_sec + (td.tv_usec / 1000000.0);
 
 	if (bytes <= 0 || elapsed <= 0.0 || cursize > filesize) {
-		len += snprintf(buf + len, sizeof(buf) - len,
+		n = snprintf(buf + len, sizeof(buf) - len,
 		    "   --:-- ETA");
 	} else if (wait.tv_sec >= STALLTIME) {
-		len += snprintf(buf + len, sizeof(buf) - len,
+		n = snprintf(buf + len, sizeof(buf) - len,
 		    " - stalled -");
 	} else {
 		remaining = 
 		    ((filesize - restart_point) / (bytes / elapsed) - elapsed);
 		if (remaining >= 100 * SECSPERHOUR)
-			len += snprintf(buf + len, sizeof(buf) - len,
+			n = snprintf(buf + len, sizeof(buf) - len,
 			    "   --:-- ETA");
 		else {
 			i = remaining / SECSPERHOUR;
 			if (i)
-				len += snprintf(buf + len, sizeof(buf) - len,
+				n = snprintf(buf + len, sizeof(buf) - len,
 				    "%2d:", i);
 			else
-				len += snprintf(buf + len, sizeof(buf) - len,
+				n = snprintf(buf + len, sizeof(buf) - len,
 				    "   ");
+ 			if (n > 0)
+				len += n;
 			i = remaining % SECSPERHOUR;
 			len += snprintf(buf + len, sizeof(buf) - len,
 			    "%02d:%02d ETA", i / 60, i % 60);
 		}
 	}
+	if (n > 0)
+		len += n;
 	(void)write(STDOUT_FILENO, buf, len);
 
 	if (flag == -1) {
@@ -711,7 +721,7 @@ ptransfer(siginfo)
 	struct timeval now, td;
 	double elapsed;
 	off_t bs;
-	int meg, remaining, hh, len;
+	int meg, n, remaining, hh, len;
 	char buf[100];
 
 	if (!verbose && !siginfo)
@@ -725,10 +735,12 @@ ptransfer(siginfo)
 	if (bs > (1024 * 1024))
 		meg = 1;
 	len = 0;
-	len += snprintf(buf + len, sizeof(buf) - len,
+	n = snprintf(buf + len, sizeof(buf) - len,
 	    "%qd byte%s %s in %.2f seconds (%.2f %sB/s)\n",
 	    (long long)bytes, bytes == 1 ? "" : "s", direction, elapsed,
 	    bs / (1024.0 * (meg ? 1024.0 : 1.0)), meg ? "M" : "K");
+	if (n > 0)
+		len += n;
 	if (siginfo && bytes > 0 && elapsed > 0.0 && filesize >= 0
 	    && bytes + restart_point <= filesize) {
 		remaining = (int)((filesize - restart_point) /
@@ -736,9 +748,11 @@ ptransfer(siginfo)
 		hh = remaining / SECSPERHOUR;
 		remaining %= SECSPERHOUR;
 		len--;	 		/* decrement len to overwrite \n */
-		len += snprintf(buf + len, sizeof(buf) - len,
+		n = snprintf(buf + len, sizeof(buf) - len,
 		    "  ETA: %02d:%02d:%02d\n", hh, remaining / 60,
 		    remaining % 60);
+		if (n > 0)
+			len += n;
 	}
 	(void)write(siginfo ? STDERR_FILENO : STDOUT_FILENO, buf, len);
 }

usr.bin/mail/fio.c

@@ -419,7 +419,7 @@ getfold(name, namelen)
 	else
 		copylen = snprintf(name, namelen, "%s/%s",
 		    homedir ? homedir : ".", folder);
-	return (copylen >= namelen ? (-1) : (0));
+	return (copylen < 0 || copylen >= namelen ? (-1) : (0));
 }
 
 /*