[2.26 COMMITTED] Fix parameter type in C++ version of iseqsig (bug 23171)

[2.26 COMMITTED] Fix parameter type in C++ version of iseqsig (bug 23171)

[Gabriel F. T. Gomes]

The commit

  commit c85e54ac6cef0faed7b7ffc722f52523dec59bf5
  Author: Gabriel F. T. Gomes <gabriel@inconstante.eti.br>
  Date:   Fri Nov 3 10:44:36 2017 -0200

      Provide a C++ version of iseqsig (bug 22377)

mistakenly used double parameters in the long double version of iseqsig,
thus causing spurious conversions to double, as reported on bug 23171.

Tested for powerpc64le and x86_64.

(cherry picked from commit fb0e10b8eb1ebb68c57d4551f7a95118f3c54837)
---
 ChangeLog   | 6 ++++++
 NEWS        | 1 +
 math/math.h | 2 +-
 3 files changed, 8 insertions(+), 1 deletion(-)

diff --git a/ChangeLog b/ChangeLog
index 0126fb391b..9c6a1b97bd 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,9 @@
+2018-05-24  Gabriel F. T. Gomes  <gabriel@inconstante.eti.br>
+
+	[BZ #23171]
+	* math/math.h [C++] (iseqsig): Fix parameter type for the long
+	double version.
+
 2018-06-01  Florian Weimer  <fweimer@redhat.com>
 
 	[BZ #23236]
diff --git a/NEWS b/NEWS
index b8bd101f6c..c323323259 100644
--- a/NEWS
+++ b/NEWS
@@ -139,6 +139,7 @@ The following bugs are resolved with this release:
   [23024] getlogin_r: return early when linux sentinel value is set
   [23037] resolv: Fully initialize struct mmsghdr in send_dg
   [23137] s390: Fix blocking pthread_join
+  [23171] Fix parameter type in C++ version of iseqsig
   [23196] __mempcpy_avx512_no_vzeroupper mishandles large copies
   [23236] Harden function pointers in _IO_str_fields
 \f
diff --git a/math/math.h b/math/math.h
index 5a282b8c6b..4c30306d58 100644
--- a/math/math.h
+++ b/math/math.h
@@ -880,7 +880,7 @@ template<> struct __iseqsig_type<double>
 
 template<> struct __iseqsig_type<long double>
 {
-  static int __call (double __x, double __y) throw ()
+  static int __call (long double __x, long double __y) throw ()
   {
 #  ifndef __NO_LONG_DOUBLE_MATH
     return __iseqsigl (__x, __y);
-- 
2.14.4