tests: seq: check for today's extended long double fix

* tests/misc/seq-long-double: New file.  Test for today's bug fix.
* tests/check.mk (TESTS_ENVIRONMENT): Export CC definition.
* tests/Makefile.am (TESTS): Add misc/seq-long-double.
* NEWS (Bug fixes): Mention it.

NEWS

@@ -6,6 +6,13 @@ GNU coreutils NEWS                                    -*- outline -*-
 
   stat -f recognizes the Lustre file system type
 
+** Bug fixes
+
+  seq 9223372036854775807 9223372036854775808 now prints only two numbers
+  on systems with extended long double support and good library support.
+  Even with this patch, on some systems, it still produces invalid output,
+  from 3 to at least 1026 lines long. [bug introduced in coreutils-6.11]
+
 ** Changes in behavior
 
   ls -l now marks SELinux-only files with the less obtrusive '.',

tests/Makefile.am

@@ -124,6 +124,7 @@ TESTS =						\
   misc/ptx					\
   misc/test					\
   misc/seq					\
+  misc/seq-long-double					\
   misc/head					\
   misc/head-elide-tail				\
   tail-2/tail-n0f				\

tests/check.mk

@@ -80,6 +80,7 @@ TESTS_ENVIRONMENT =				\
   top_srcdir='$(top_srcdir)'			\
   CONFIG_HEADER='$(abs_top_builddir)/lib/config.h' \
   CU_TEST_NAME=`basename '$(abs_srcdir)'`,$$tst	\
+  CC='$(CC)'					\
   AWK='$(AWK)'					\
   EGREP='$(EGREP)'				\
   EXEEXT='$(EXEEXT)'				\

tests/misc/seq-long-double

@@ -0,0 +1,51 @@
+#!/bin/sh
+# Test for this fix: 461231f022bdb3ee392622d31dc475034adceeb2.
+# Ensure that seq prints exactly two numbers for a 2-number integral
+# range at the limit of floating point precision.
+
+# Copyright (C) 2008 Free Software Foundation, Inc.
+
+# This program is free software: you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation, either version 3 of the License, or
+# (at your option) any later version.
+
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+
+# You should have received a copy of the GNU General Public License
+# along with this program.  If not, see <http://www.gnu.org/licenses/>.
+
+if test "$VERBOSE" = yes; then
+  set -x
+  seq --version
+fi
+
+. $srcdir/test-lib.sh
+
+# Run this test only with glibc and sizeof (long double) > sizeof (double).
+# Otherwise, there are known failures:
+# http://thread.gmane.org/gmane.comp.gnu.coreutils.bugs/14939/focus=14944
+cat <<\EOF > long.c
+#include <features.h>
+#if defined __GNU_LIBRARY__ && __GLIBC__ >= 2
+int foo[sizeof (long double) - sizeof (double) - 1];
+#else
+"run this test only with glibc"
+#endif
+EOF
+$CC -c long.c \
+  || skip_test_ \
+     'this test runs only on systems with glibc and long double != double'
+
+a=9223372036854775807
+b=$(echo $a|sed 's/7$/8/')
+
+fail=0
+seq $a $b > out || fail=1
+printf "$a\n$b\n" > exp || fail=1
+compare out exp || fail=1
+
+Exit $fail