mktemp, sort, tac: don't use undefined after mkstemp failure

When mkstemp fails, the template buffer may have undefined
contents, so we must not print it.
* src/sort.c (create_temp_file): Use temp_dir, not "file"
when diagnosing failed mkstemp, because "file" may be undefined.
* tests/misc/sort-merge: Adjust for new expected output.
Jeph Cowan and Ralf Wildenhues reported the test failure:
http://thread.gmane.org/gmane.comp.gnu.coreutils.bugs/14235/focus=14257
* src/tac.c (copy_to_temp): Don't use template buffer after
failed mkstemp call, since its contents may be undefined.
* tests/misc/tac (pipe-bad-tmpdir): New test for the above.
* src/mktemp.c (main): Save a copy of the template string,
solely for use in case mkstemp fails.
* tests/misc/mktemp (pipe-bad-tmpdir): New test for the above.

3 files changed, 19 insertions, 2 deletions

diff --git a/tests/misc/mktemp b/tests/misc/mktemp
index 616a9e44f..356558291 100755
--- a/tests/misc/mktemp
+++ b/tests/misc/mktemp
@@ -49,6 +49,7 @@ sub check_tmp($$)
 # Turn off localization of executable's output.
 @ENV{qw(LANGUAGE LANG LC_ALL)} = ('C') x 3;
 my $prog = 'mktemp';
+my $bad_dir = 'no/such/dir';
 
 my @Tests =
     (
@@ -97,6 +98,12 @@ my @Tests =
       {POST => sub { my ($f) = @_; defined $f or return; chomp $f;
        check_tmp $f, 'F'; unlink $f; rmdir 'a' or die "rmdir a: $!\n" }}
      ],
+
+     ['pipe-bad-tmpdir',
+      {ENV => "TMPDIR=$bad_dir"},
+      {ERR_SUBST => "s,($bad_dir/)[^']+': .*,\$1...,"},
+      {ERR => "$prog: failed to create file via template `$bad_dir/...\n"},
+      {EXIT => 1}],
     );
 
 my $save_temps = $ENV{DEBUG};
diff --git a/tests/misc/sort-merge b/tests/misc/sort-merge
index 985d7a414..6b8192610 100755
--- a/tests/misc/sort-merge
+++ b/tests/misc/sort-merge
@@ -66,8 +66,9 @@ my @Tests =
      # this should fail since nmerge < # of input files, so
      # temp files are needed
      ['nmerge-no', "-m --batch-size=2 -T$badtmp", @inputs,
-        {ERR_SUBST=>"s|: $badtmp/sort.+||"},
-        {ERR=>"$prog: cannot create temporary file\n"}, {EXIT=>2}],
+        {ERR_SUBST=>"s|': .*|':|"},
+        {ERR=>"$prog: cannot create temporary file in `$badtmp':\n"},
+	{EXIT=>2}],
 
      # This used to fail because setting batch-size without also setting
      # buffer size would cause the buffer size to be set to the minimum.
diff --git a/tests/misc/tac b/tests/misc/tac
index 2f9981d49..9995357ab 100755
--- a/tests/misc/tac
+++ b/tests/misc/tac
@@ -22,6 +22,8 @@ my $prog = 'tac';
 # Turn off localization of executable's output.
 @ENV{qw(LANGUAGE LANG LC_ALL)} = ('C') x 3;
 
+my $bad_dir = 'no/such/dir';
+
 my @Tests =
 (
   ['segfault', '-r', {IN=>"a\n"}, {IN=>"b\n"}, {OUT=>"a\nb\n"}],
@@ -58,6 +60,13 @@ my @Tests =
   ['opt-br2', qw(-b -r -s '\._+'),
    {IN=>".__x.___y.____z._1._2.__3.___4"},
    {OUT=>".___4.__3._2._1.____z.___y.__x"}],
+
+  ['pipe-bad-tmpdir',
+   {ENV => "TMPDIR=$bad_dir"},
+   {IN_PIPE => "a\n"},
+   {ERR_SUBST => "s,`$bad_dir': .*,...,"},
+   {ERR => "$prog: cannot create temporary file in ...\n"},
+   {EXIT => 1}],
 );
 
 @Tests = triple_test \@Tests;