tee: treat '-' operand as file name as mandated by POSIX

Since v5.2.1-1247-g8dafbe5, tee(1) treated '-' as stdout while POSIX
explicitly requires to treat this as a file name.  Revert this change,
as the interleaved output - due to sending another copy of input to
stdout - is not considered to be useful.  Discussed in
http://lists.gnu.org/archive/html/coreutils/2015-02/msg00085.html

* src/tee.c (tee_files): Remove the special handling for "-" operands.
(usage): Remove the corresponding sentence.
* doc/coreutils.texi (common options): Remove the "tee -" example.
(tee invocation): Document that tee(1) now treats "-" as a file name.
* tests/misc/tee.sh: Add a test case for "tee -".
While at it, re-indent the above multi-argument processing case and
extend that to 13 operands, as POSIX mandates that, too.
* tests/misc/tee-dash.sh: Remove now-obsolete test.
* tests/local.mk (all_tests): Remove the above test.
* NEWS (Changes in behavior): Mention the change.

1 files changed, 2 insertions, 7 deletions

diff --git a/src/tee.c b/src/tee.c
index bfe1b6900..feb402628 100644
--- a/src/tee.c
+++ b/src/tee.c
@@ -68,10 +68,6 @@ Copy standard input to each FILE, and also to standard output.\n\
 "), stdout);
       fputs (HELP_OPTION_DESCRIPTION, stdout);
       fputs (VERSION_OPTION_DESCRIPTION, stdout);
-      fputs (_("\
-\n\
-If a FILE is -, copy again to standard output.\n\
-"), stdout);
       emit_ancillary_info (PROGRAM_NAME);
     }
   exit (status);
@@ -169,9 +165,8 @@ tee_files (int nfiles, const char **files)
 
   for (i = 1; i <= nfiles; i++)
     {
-      descriptors[i] = (STREQ (files[i], "-")
-                        ? stdout
-                        : fopen (files[i], mode_string));
+      /* Do not treat "-" specially - as mandated by POSIX.  */
+      descriptors[i] = fopen (files[i], mode_string);
       if (descriptors[i] == NULL)
         {
           error (0, errno, "%s", files[i]);