xargs: fix parsing of empty fields when "xargs -0" is used.

Previously, these fields would be skipped.  From Hiltjo Posthuma.

diff --git a/regress/usr.bin/xargs/xargs-L.sh b/regress/usr.bin/xargs/xargs-L.sh
index 50477de..7f4a329 100755 (executable)
--- a/regress/usr.bin/xargs/xargs-L.sh
+++ b/regress/usr.bin/xargs/xargs-L.sh
@@ -1,6 +1,6 @@
 #!/bin/sh
 #
-# $OpenBSD: xargs-L.sh,v 1.3 2017/10/16 13:48:22 anton Exp $
+# $OpenBSD: xargs-L.sh,v 1.4 2023/12/22 17:12:13 millert Exp $
 #
 # written by Ingo Schwarze <schwarze@openbsd.org> 2010
 # and placed in the public domain
@@ -97,3 +97,11 @@ test_xargs 'a\n\\\nb\0c' '-0 -L 1' 'a\n\\\nb|\nc|'
 test_xargs 'a \\\nb\0c'  '-0 -L 1' 'a \\\nb|\nc|'
 test_xargs 'a\\\n b\0c'  '-0 -L 1' 'a\\\n b|\nc|'
 test_xargs 'a \\\n b\0c' '-0 -L 1' 'a \\\n b|\nc|'
+
+test_xargs 'a'           '-0 -L 1' 'a|\n'
+test_xargs 'a\0'         '-0 -L 1' 'a|\n'
+test_xargs 'a\0\0'       '-0 -L 1' 'a|\n|\n'
+test_xargs 'a\0\0b'      '-0 -L 2' 'a||\nb|'
+test_xargs 'a\0\0b'      '-0 -L 1' 'a|\n|\nb|'
+test_xargs 'a\0\0b'      '-0 -L 3' 'a||b|'
+test_xargs 'a\0\0b'      '-0 -L 9' 'a||b|'

diff --git a/usr.bin/xargs/xargs.c b/usr.bin/xargs/xargs.c
index ff17caa..70f9d9d 100644 (file)
--- a/usr.bin/xargs/xargs.c
+++ b/usr.bin/xargs/xargs.c
@@ -1,4 +1,4 @@
-/*     $OpenBSD: xargs.c,v 1.36 2022/12/04 23:50:50 cheloha Exp $      */
+/*     $OpenBSD: xargs.c,v 1.37 2023/12/22 17:12:13 millert Exp $      */
 /*     $FreeBSD: xargs.c,v 1.51 2003/05/03 19:09:11 obrien Exp $       */
 
 /*-
@@ -297,7 +297,7 @@ arg2:
                    strcmp(argp, eofstr) == 0;
 
                /* Do not make empty args unless they are quoted */
-               if ((argp != p || wasquoted) && !foundeof) {
+               if ((zflag || argp != p || wasquoted) && !foundeof) {
                        *p++ = '\0';
                        *xp++ = argp;
                        if (Iflag) {