join: Add the -z, --zero-terminated option

* NEWS: Mention join's new option: --zero-terminated (-z).
* src/join.c: Add new option, --zero-terminated (-z), to make
join use the NUL byte as separator/delimiter rather than newline.
(get_line): Use readlinebuffer_delim in place of readlinebuffer.
(main): Handle the new option.
(usage): Describe new option the same way sort does.
* doc/coreutils.texi (join invocation): Describe the new option.
* tests/misc/join.pl: add tests for -z option.

1 files changed, 20 insertions, 0 deletions

diff --git a/tests/misc/join.pl b/tests/misc/join.pl
index 9b93794d9..7e06f1e6c 100755
--- a/tests/misc/join.pl
+++ b/tests/misc/join.pl
@@ -275,6 +275,26 @@ my @tv = (
  [ "ID1 Name\n1 A\n", ""],
    "ID1 Name\n1 A\n", 0],
 
+# Zero-terminated lines
+['z1', '-z',
+ ["a\0c\0e\0", "a\0b\0c\0"], "a\0c\0", 0],
+
+# not zero-terminated, but related to the code change:
+#  the old readlinebuffer() auto-added '\n' to the last line.
+#  the new readlinebuffer_delim() does not.
+#  Ensure it doesn't matter.
+['z2', '',
+ ["a\nc\ne\n", "a\nb\nc"], "a\nc\n", 0],
+['z3', '',
+ ["a\nc\ne", "a\nb\nc"], "a\nc\n", 0],
+# missing last NUL at the end of the last line (=end of file)
+['z4', '-z',
+ ["a\0c\0e", "a\0b\0c"], "a\0c\0", 0],
+# edge-case: the embedded newlines should treated as
+# part of the nul-terminated line
+['z5', '-z -a1 -a2',
+ ["a\n1\0c 3\0","b\n8\0c 9\0"], "a\n1\0b\n8\0c 3 9\0"],
+
 );
 
 # Convert the above old-style test vectors to the newer