Index: head/usr.bin/xargs/tests/Makefile
===================================================================
--- head/usr.bin/xargs/tests/Makefile
+++ head/usr.bin/xargs/tests/Makefile
@@ -10,13 +10,16 @@
 FILES+=		regress.0I.out
 FILES+=		regress.0J.out
 FILES+=		regress.0L.out
+FILES+=		regress.0P1.out
 FILES+=		regress.I.out
 FILES+=		regress.J.out
 FILES+=		regress.L.out
+FILES+=		regress.P1.out
 FILES+=		regress.R.out
 FILES+=		regress.in
 FILES+=		regress.n1.out
 FILES+=		regress.n2.out
+FILES+=		regress.n2P0.out
 FILES+=		regress.n3.out
 FILES+=		regress.normal.out
 FILES+=		regress.quotes.in
Index: head/usr.bin/xargs/tests/regress.0P1.out
===================================================================
--- head/usr.bin/xargs/tests/regress.0P1.out
+++ head/usr.bin/xargs/tests/regress.0P1.out
@@ -0,0 +1,4 @@
+quick ' brown fox jumped
+over	"the lazy dog
+quick brown fox jumped over the lazy dog
+
Index: head/usr.bin/xargs/tests/regress.P1.out
===================================================================
--- head/usr.bin/xargs/tests/regress.P1.out
+++ head/usr.bin/xargs/tests/regress.P1.out
@@ -0,0 +1 @@
+quick brown fox jumped over the lazy dog
Index: head/usr.bin/xargs/tests/regress.n2P0.out
===================================================================
--- head/usr.bin/xargs/tests/regress.n2P0.out
+++ head/usr.bin/xargs/tests/regress.n2P0.out
@@ -0,0 +1,4 @@
+quick brown
+fox jumped
+over the
+lazy dog
Index: head/usr.bin/xargs/tests/regress.sh
===================================================================
--- head/usr.bin/xargs/tests/regress.sh
+++ head/usr.bin/xargs/tests/regress.sh
@@ -1,6 +1,6 @@
 # $FreeBSD$
 
-echo 1..13
+echo 1..16
 
 REGRESSION_START($1)
 
@@ -8,14 +8,17 @@
 REGRESSION_TEST(`I', `xargs -I% echo The % % % %% % % <${SRCDIR}/regress.in')
 REGRESSION_TEST(`J', `xargs -J% echo The % again. <${SRCDIR}/regress.in')
 REGRESSION_TEST(`L', `xargs -L3 echo <${SRCDIR}/regress.in')
+REGRESSION_TEST(`P1', `xargs -P1 echo <${SRCDIR}/regress.in')
 REGRESSION_TEST(`R', `xargs -I% -R1 echo The % % % %% % % <${SRCDIR}/regress.in')
 REGRESSION_TEST(`n1', `xargs -n1 echo <${SRCDIR}/regress.in')
 REGRESSION_TEST(`n2', `xargs -n2 echo <${SRCDIR}/regress.in')
+REGRESSION_TEST(`n2P0',`xargs -n2 -P0 echo <${SRCDIR}/regress.in')
 REGRESSION_TEST(`n3', `xargs -n3 echo <${SRCDIR}/regress.in')
 REGRESSION_TEST(`0', `xargs -0 -n1 echo <${SRCDIR}/regress.0.in')
 REGRESSION_TEST(`0I', `xargs -0 -I% echo The % %% % <${SRCDIR}/regress.0.in')
 REGRESSION_TEST(`0J', `xargs -0 -J% echo The % again. <${SRCDIR}/regress.0.in')
 REGRESSION_TEST(`0L', `xargs -0 -L2 echo <${SRCDIR}/regress.0.in')
+REGRESSION_TEST(`0P1', `xargs -0 -P1 echo <${SRCDIR}/regress.0.in')
 REGRESSION_TEST(`quotes', `xargs -n1 echo <${SRCDIR}/regress.quotes.in')
 
 REGRESSION_END()
Index: head/usr.bin/xargs/xargs.c
===================================================================
--- head/usr.bin/xargs/xargs.c
+++ head/usr.bin/xargs/xargs.c
@@ -166,15 +166,11 @@
 			oflag = 1;
 			break;
 		case 'P':
-			maxprocs = strtonum(optarg, 1, INT_MAX, &errstr);
+			maxprocs = strtonum(optarg, 0, INT_MAX, &errstr);
 			if (errstr)
 				errx(1, "-P %s: %s", optarg, errstr);
 			if (getrlimit(RLIMIT_NPROC, &rl) != 0)
 				errx(1, "getrlimit failed");
-			if (*endptr != '\0')
-				errx(1, "invalid number for -P option");
-			if (maxprocs < 0)
-				errx(1, "value for -P option should be >= 0");
 			if (maxprocs == 0 || maxprocs > rl.rlim_cur)
 				maxprocs = rl.rlim_cur;
 			break;