"cut -f 2- A B" no longer triggers a double-free bug

* src/cut.c (cut_fields): Set file-scoped global to NULL after
freeing it.  This avoids a double-free (and core dump on some systems)
for this usage: "echo 1>a; echo 2>b; cut -f2- a b".  Reported by
James Hunt in <http://bugzilla.redhat.com/220312>.
* NEWS: List this bug fix.
* THANKS: Mention him.
* tests/misc/cut: New file.
* tests/misc/Makefile.am (TESTS): Add cut.

1 files changed, 1 insertions, 0 deletions

diff --git a/src/cut.c b/src/cut.c
index 73277faa3..c9b83595a 100644
--- a/src/cut.c
+++ b/src/cut.c
@@ -606,6 +606,7 @@ cut_fields (FILE *stream)
 	  if (len < 0)
 	    {
 	      free (field_1_buffer);
+	      field_1_buffer = NULL;
 	      if (ferror (stream) || feof (stream))
 		break;
 	      xalloc_die ();