Index: sort.c
===================================================================
RCS file: /cvsroot/src/usr.bin/sort/sort.c,v
retrieving revision 1.63
diff -u -r1.63 sort.c
--- sort.c	1 Jun 2016 08:24:03 -0000	1.63
+++ sort.c	27 Dec 2016 04:57:37 -0000
@@ -156,7 +156,7 @@
 	while ((ch = getopt(argc, argv, SORT_OPTS)) != -1) {
 		switch (ch) {
 		case 'b':
-			fldtab[0].flags |= BI | BT;
+			fldtab[fld_cnt].flags |= BI | BT;
 			break;
 		case 'c': case 'C': case 'm':
 			if (mode)
@@ -168,7 +168,7 @@
 			    debug_flags |= 1 << (optarg[i] & 31);
 			break;
 		case 'd': case 'f': case 'i': case 'n': case 'l':
-			fldtab[0].flags |= optval(ch, 0);
+			fldtab[fld_cnt].flags |= optval(ch, 0);
 			break;
 		case 'H':
 			/* -H was ; use merge sort for blocks of large files' */
@@ -176,8 +176,7 @@
 			break;
 		case 'k':
 			fldtab = erealloc(fldtab, (fldtab_sz + 1) * sizeof(*fldtab));
-			memset(&fldtab[fldtab_sz], 0, sizeof(fldtab[0]));
-			fldtab_sz++;
+			memset(&fldtab[fldtab_sz++], 0, sizeof(fldtab[0]));
 
 			setfield(optarg, &fldtab[++fld_cnt], fldtab[0].flags);
 			break;