From b005000525ab0a5116d21217c41fb1da5bd03796 Mon Sep 17 00:00:00 2001
From: Jonathan Wakely <jwakely@redhat.com>
Date: Fri, 6 May 2022 21:19:17 +0100
Subject: [PATCH] libstdc++: Fix deserialization for std::normal_distribution
[PR105502]
This fixes a regression in std::normal_distribution deserialization that
caused the object to be left unchanged if the __state_avail value read
from the stream was false.
libstdc++-v3/ChangeLog:
PR libstdc++/105502
* include/bits/random.tcc
(operator>>(basic_istream<C,T>&, normal_distribution<R>&)):
Update state when __state_avail is false.
* testsuite/26_numerics/random/normal_distribution/operators/serialize.cc:
Check that deserialized object equals serialized one.
(cherry picked from commit 909ef4e2727ddc50a32d6ad379a1f1ccc1043c6a)
---
libstdc++-v3/include/bits/random.tcc | 2 +-
.../operators/serialize.cc | 36 ++++++++++++++++++-
2 files changed, 36 insertions(+), 2 deletions(-)
diff --git a/libstdc++-v3/include/bits/random.tcc b/libstdc++-v3/include/bits/random.tcc
index 0a299baedc5..0f758671f69 100644
--- a/libstdc++-v3/include/bits/random.tcc
+++ b/libstdc++-v3/include/bits/random.tcc
@@ -1941,7 +1941,7 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
bool __saved_avail;
if (__is >> __mean >> __stddev >> __saved_avail)
{
- if (__saved_avail && (__is >> __x._M_saved))
+ if (!__saved_avail || (__is >> __x._M_saved))
{
__x._M_saved_available = __saved_avail;
__x.param(typename normal_distribution<_RealType>::
diff --git a/libstdc++-v3/testsuite/26_numerics/random/normal_distribution/operators/serialize.cc b/libstdc++-v3/testsuite/26_numerics/random/normal_distribution/operators/serialize.cc
index a65d4004161..8cc70886bc7 100644
--- a/libstdc++-v3/testsuite/26_numerics/random/normal_distribution/operators/serialize.cc
+++ b/libstdc++-v3/testsuite/26_numerics/random/normal_distribution/operators/serialize.cc
@@ -25,6 +25,7 @@
#include <random>
#include <sstream>
+#include <testsuite_hooks.h>
void
test01()
@@ -37,10 +38,43 @@ test01()
str << u;
str >> v;
+ VERIFY( u == v );
+}
+
+void
+test_pr105502()
+{
+ // PR libstdc++/105502 std::normal_distribution deserialization issue
+ std::stringstream str;
+ std::normal_distribution<> d{1, 2}, d2;
+ std::minstd_rand0 g;
+ str << d;
+ VERIFY( str );
+ str >> d2;
+ VERIFY( str );
+ VERIFY( d == d2 );
+
+ (void) d(g); // sets d._M_saved_available = true
+ str.str("");
+ str.clear();
+ str << d;
+ VERIFY( str );
+ str >> d2;
+ VERIFY( str );
+ VERIFY( d == d2 );
+
+ (void) d(g); // sets d._M_saved_available = false
+ str.str("");
+ str.clear();
+ str << d;
+ VERIFY( str );
+ str >> d2;
+ VERIFY( str );
+ VERIFY( d == d2 );
}
int main()
{
test01();
- return 0;
+ test_pr105502();
}
--
2.31.1