random.tcc (piecewise_linear_distribution<>:: operator()): Don't crash when the…

random.tcc (piecewise_linear_distribution<>:: operator()): Don't crash when the dist is default-constructed.

2010-10-12  Paolo Carlini  <paolo.carlini@oracle.com>

	* include/bits/random.tcc (piecewise_linear_distribution<>::
	operator()): Don't crash when the dist is default-constructed.
	* testsuite/26_numerics/random/piecewise_linear_distribution/
	operators/call-default.cc: New.

From-SVN: r165379

libstdc++-v3/ChangeLog

+2010-10-12  Paolo Carlini  <paolo.carlini@oracle.com>
+
+	* include/bits/random.tcc (piecewise_linear_distribution<>::
+	operator()): Don't crash when the dist is default-constructed.
+	* testsuite/26_numerics/random/piecewise_linear_distribution/
+	operators/call-default.cc: New.
+
 2010-10-11  Jonathan Wakely  <jwakely.gcc@gmail.com>
 
 	* testsuite/23_containers/bitset/cons/2.cc: Tweak.

libstdc++-v3/include/bits/random.tcc

@@ -2623,6 +2623,9 @@ namespace std
 	  __aurng(__urng);
 
 	const double __p = __aurng();
+	if (__param._M_m.empty())
+	  return __p;
+
 	auto __pos = std::lower_bound(__param._M_cp.begin(),
 				      __param._M_cp.end(), __p);
 	const size_t __i = __pos - __param._M_cp.begin();

libstdc++-v3/testsuite/26_numerics/random/piecewise_linear_distribution/operators/call-default.cc

+// { dg-options "-std=c++0x" }
+// { dg-require-cstdint "" }
+//
+// 2010-10-12  Paolo Carlini  <paolo.carlini@oracle.com>
+//
+// Copyright (C) 2010 Free Software Foundation, Inc.
+//
+// This file is part of the GNU ISO C++ Library.  This library 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, or (at your option)
+// any later version.
+//
+// This library 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 library; see the file COPYING3.  If not see
+// <http://www.gnu.org/licenses/>.
+
+// 26.5.8.5.3 Class template piecewise_linear_distribution
+//   [rand.dist.samp.plinear]
+
+#include <random>
+
+void
+test01()
+{
+  std::piecewise_linear_distribution<> u;
+  std::minstd_rand0 rng;
+
+  u(rng);
+}
+
+int main()
+{
+  test01();
+  return 0;
+}