PR libstdc++/87872 Avoids iterator transfer on self splice

[Jonathan Wakely]

On 06/11/18 10:49 +0100, François Dumont wrote:
>Here is the patch submitted by John and now fully tested.
>
>Â Â Â  PR libstdc++/87872
>Â Â Â  * include/debug/safe_sequence.tcc
>Â Â Â  (_Safe_sequence<>::_M_transfer_from_if): Skip transfer to self.
>
>Is it fine to commit it now ?

OK, thanks.


>François
>

>diff --git a/libstdc++-v3/include/debug/safe_sequence.tcc b/libstdc++-v3/include/debug/safe_sequence.tcc
>index 12de48cf322..ce9a807e79f 100644
>--- a/libstdc++-v3/include/debug/safe_sequence.tcc
>+++ b/libstdc++-v3/include/debug/safe_sequence.tcc
>@@ -68,6 +68,9 @@ namespace __gnu_debug
>       _Safe_sequence<_Sequence>::
>       _M_transfer_from_if(_Safe_sequence& __from, _Predicate __pred)
>       {
>+	if (this == std::__addressof(__from))
>+	  return;
>+
> 	typedef typename _Sequence::iterator iterator;
> 	typedef typename _Sequence::const_iterator const_iterator;
>