Handle snprintf() returning -1.

MFC after:	2 weeks

1 files changed, 5 insertions, 2 deletions

diff --git a/usr.sbin/diskcheckd/diskcheckd.c b/usr.sbin/diskcheckd/diskcheckd.c
index 558b583..cb79a08 100644
--- a/usr.sbin/diskcheckd/diskcheckd.c
+++ b/usr.sbin/diskcheckd/diskcheckd.c
@@ -443,8 +443,9 @@ updateproctitle(struct disk *disks) {
 			p += sizeof _PATH_DEV - 1;
 
 		percent = 100 * (double)dseek(dp, 0, SEEK_CUR) / dp->size;
-		if ((size_t)(ret = snprintf(bp, size,
-		    "%s %.2f%%, ", p, percent)) >= size) {
+		if ((ret = snprintf(bp, size, "%s %.2f%%, ", p, percent)) == -1)
+			ret = 0;
+		if ((size_t)ret >= size) {
 			inc = ((ret + 1023) >> 10) << 10;
 			size += inc;
 			bufsize += inc;
@@ -456,6 +457,8 @@ updateproctitle(struct disk *disks) {
 			}
 			bp = buf + bufsize - size;
 			ret = snprintf(bp, size, "%s %.2f%%, ", p, percent);
+			if (ret == -1)
+				ret = 0;
 		}
 		bp += ret;
 		size -= ret;