[PATCH] libstdc++: istreambuf_iterator keep attached streambuf

[Jonathan Wakely]

On 23/09/17 09:54 +0300, Petr Ovtchenkov wrote:
>istreambuf_iterator should not forget about attached
>streambuf when it reach EOF.
>
>Checks in debug mode has no infuence more on character
>extraction in istreambuf_iterator increment operators.
>In this aspect behaviour in debug and non-debug mode
>is similar now.
>
>Test for detached srteambuf in istreambuf_iterator:
>When istreambuf_iterator reach EOF of istream, it should not
>forget about attached streambuf.
>From fact "EOF in stream reached" not follow that
>stream reach end of life and input operation impossible
>more.
>---
> libstdc++-v3/include/bits/streambuf_iterator.h     | 41 +++++++--------
> .../24_iterators/istreambuf_iterator/3.cc          | 61 ++++++++++++++++++++++
> 2 files changed, 80 insertions(+), 22 deletions(-)
> create mode 100644 libstdc++-v3/testsuite/24_iterators/istreambuf_iterator/3.cc
>
>diff --git a/libstdc++-v3/include/bits/streambuf_iterator.h b/libstdc++-v3/include/bits/streambuf_iterator.h
>index f0451b1..45c3d89 100644
>--- a/libstdc++-v3/include/bits/streambuf_iterator.h
>+++ b/libstdc++-v3/include/bits/streambuf_iterator.h
>@@ -136,12 +136,20 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
>       istreambuf_iterator&
>       operator++()
>       {
>-	__glibcxx_requires_cond(!_M_at_eof(),
>+	__glibcxx_requires_cond(_M_sbuf,
> 				_M_message(__gnu_debug::__msg_inc_istreambuf)
> 				._M_iterator(*this));
> 	if (_M_sbuf)
> 	  {
>+#ifdef _GLIBCXX_DEBUG_PEDANTIC
>+	    int_type _tmp =

_tmp is not a reserved name, this needs to be __tmp.

I'm still reviewing the rest, to understand what observable behaviour
this changes, and how it differs from the patch François sent.