2005-01-05 Paolo Carlini <pcarlini@suse.de>

	* src/istream.cc (basic_istream<char>::ignore(streamsize),
	basic_istream<char>::ignore(streamsize, int_type),
	basic_istream<wchar_t>::ignore(streamsize),
	basic_istream<wchar_t>::ignore(streamsize, int_type)): At the end,
	first check _M_gcount vs __n.
	* include/bits/istream.tcc (ignore(streamsize), ignore(streamsize,
	int_type)): Likewise.
	* testsuite/27_io/basic_istream/ignore/char/4.cc: New.
	* testsuite/27_io/basic_istream/ignore/wchar_t/4.cc: Likewise.


git-svn-id: https://gcc.gnu.org/svn/gcc/trunk@92947 138bc75d-0d04-0410-961f-82ee72b054a4

5 files changed, 155 insertions, 10 deletions

diff --git a/libstdc++-v3/ChangeLog b/libstdc++-v3/ChangeLog
index 12119bf3695..8322d5f9efc 100644
--- a/libstdc++-v3/ChangeLog
+++ b/libstdc++-v3/ChangeLog
@@ -1,3 +1,15 @@
+2005-01-05  Paolo Carlini  <pcarlini@suse.de>
+
+	* src/istream.cc (basic_istream<char>::ignore(streamsize),
+	basic_istream<char>::ignore(streamsize, int_type),
+	basic_istream<wchar_t>::ignore(streamsize),
+	basic_istream<wchar_t>::ignore(streamsize, int_type)): At the end,
+	first check _M_gcount vs __n. 	
+	* include/bits/istream.tcc (ignore(streamsize), ignore(streamsize,
+	int_type)): Likewise.
+	* testsuite/27_io/basic_istream/ignore/char/4.cc: New.
+	* testsuite/27_io/basic_istream/ignore/wchar_t/4.cc: Likewise.
+
 2005-01-03  Mark Mitchell  <mark@codesourcery.com>
 
 	* testsuite/testsuite_hooks.cc: Use __throw_exception_again
diff --git a/libstdc++-v3/include/bits/istream.tcc b/libstdc++-v3/include/bits/istream.tcc
index 573c179615e..876f626acfc 100644
--- a/libstdc++-v3/include/bits/istream.tcc
+++ b/libstdc++-v3/include/bits/istream.tcc
@@ -685,6 +685,13 @@ namespace std
               __streambuf_type* __sb = this->rdbuf();
               int_type __c = __sb->sgetc();
 
+	      // N.B. On LFS-enabled platforms streamsize is still 32 bits
+	      // wide: if we want to implement the standard mandated behavior
+	      // for n == max() (see 27.6.1.3/24) we are at risk of signed
+	      // integer overflow: thus these contortions. Also note that,
+	      // by definition, when more than 2G chars are actually ignored,
+	      // _M_gcount (the return value of gcount, that is) cannot be
+	      // really correct, being unavoidably too small.
 	      while (true)
 		{
 		  while (_M_gcount < __n
@@ -700,7 +707,7 @@ namespace std
 		    break;
 		}
 
-	      if (traits_type::eq_int_type(__c, __eof))
+	      if (_M_gcount < __n)
                 __err |= ios_base::eofbit;
             }
           catch(...)
@@ -730,6 +737,7 @@ namespace std
               __streambuf_type* __sb = this->rdbuf();
               int_type __c = __sb->sgetc();
 
+	      // See comment above.
 	      while (true)
 		{
 		  while (_M_gcount < __n
@@ -747,9 +755,11 @@ namespace std
 		    break;
 		}
 
-              if (traits_type::eq_int_type(__c, __eof))
+	      if (_M_gcount == __n)
+		;
+              else if (traits_type::eq_int_type(__c, __eof))
                 __err |= ios_base::eofbit;
-	      else if (traits_type::eq_int_type(__c, __delim))
+	      else
 		{
 		  ++_M_gcount;
 		  __sb->sbumpc();
diff --git a/libstdc++-v3/src/istream.cc b/libstdc++-v3/src/istream.cc
index 5bdcaaf6b59..dc99051a022 100644
--- a/libstdc++-v3/src/istream.cc
+++ b/libstdc++-v3/src/istream.cc
@@ -123,7 +123,8 @@ namespace std
 	      const int_type __eof = traits_type::eof();
 	      __streambuf_type* __sb = this->rdbuf();
 	      int_type __c = __sb->sgetc();
-	      
+
+	      // See comment in istream.tcc.
 	      while (true)
 		{
 		  while (_M_gcount < __n
@@ -151,7 +152,7 @@ namespace std
 		    break;
 		}
 
-	      if (traits_type::eq_int_type(__c, __eof))
+	      if (_M_gcount < __n)
 		__err |= ios_base::eofbit;
 	    }
 	  catch(...)
@@ -216,9 +217,11 @@ namespace std
 		    break;
 		}
 
-	      if (traits_type::eq_int_type(__c, __eof))
+	      if (_M_gcount == __n)
+		;
+	      else if (traits_type::eq_int_type(__c, __eof))
 		__err |= ios_base::eofbit;
-	      else if (traits_type::eq_int_type(__c, __delim))
+	      else
 		{
 		  ++_M_gcount;
 		  __sb->sbumpc();
@@ -429,7 +432,7 @@ namespace std
 		    break;
 		}
 
-	      if (traits_type::eq_int_type(__c, __eof))
+	      if (_M_gcount < __n)
 		__err |= ios_base::eofbit;
 	    }
 	  catch(...)
@@ -494,9 +497,11 @@ namespace std
 		    break;
 		}
 
-	      if (traits_type::eq_int_type(__c, __eof))
+	      if (_M_gcount == __n)
+		;
+	      else if (traits_type::eq_int_type(__c, __eof))
 		__err |= ios_base::eofbit;
-	      else if (traits_type::eq_int_type(__c, __delim))
+	      else
 		{
 		  ++_M_gcount;
 		  __sb->sbumpc();
diff --git a/libstdc++-v3/testsuite/27_io/basic_istream/ignore/char/4.cc b/libstdc++-v3/testsuite/27_io/basic_istream/ignore/char/4.cc
new file mode 100644
index 00000000000..474f6a9d04c
--- /dev/null
+++ b/libstdc++-v3/testsuite/27_io/basic_istream/ignore/char/4.cc
@@ -0,0 +1,59 @@
+// 2005-01-05  Paolo Carlini  <pcarlini@suse.de>
+
+// Copyright (C) 2005 Free Software Foundation
+//
+// 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 2, 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 COPYING.  If not, write to the Free
+// Software Foundation, 59 Temple Place - Suite 330, Boston, MA 02111-1307,
+// USA.
+
+// 27.6.1.3 unformatted input functions
+
+#include <istream>
+#include <sstream>
+#include <testsuite_hooks.h>
+
+void
+test01()
+{
+  using namespace std;
+  bool test __attribute__((unused)) = true;
+
+  const string str_01("Gesang der junglinge");
+  ios_base::iostate state1, state2;
+
+  stringbuf isbuf_01(str_01, ios_base::in);
+  istream is_01(&isbuf_01);
+
+  state1 = is_01.rdstate();
+  VERIFY( state1 == ios_base::goodbit );
+
+  is_01.ignore(11, 'j');
+  VERIFY( is_01.gcount() == 11 );
+  state2 = is_01.rdstate();
+  VERIFY( state2 == state1 );
+  VERIFY( is_01.peek() == 'j' );
+
+  is_01.ignore(9);
+  VERIFY( is_01.gcount() == 9 );
+  state2 = is_01.rdstate();
+  VERIFY( state2 == state1 );
+}
+
+int 
+main()
+{
+  test01();
+  return 0;
+}
diff --git a/libstdc++-v3/testsuite/27_io/basic_istream/ignore/wchar_t/4.cc b/libstdc++-v3/testsuite/27_io/basic_istream/ignore/wchar_t/4.cc
new file mode 100644
index 00000000000..361811754ce
--- /dev/null
+++ b/libstdc++-v3/testsuite/27_io/basic_istream/ignore/wchar_t/4.cc
@@ -0,0 +1,59 @@
+// 2005-01-05  Paolo Carlini  <pcarlini@suse.de>
+
+// Copyright (C) 2005 Free Software Foundation
+//
+// 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 2, 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 COPYING.  If not, write to the Free
+// Software Foundation, 59 Temple Place - Suite 330, Boston, MA 02111-1307,
+// USA.
+
+// 27.6.1.3 unformatted input functions
+
+#include <istream>
+#include <sstream>
+#include <testsuite_hooks.h>
+
+void
+test01()
+{
+  using namespace std;
+  bool test __attribute__((unused)) = true;
+
+  const wstring str_01(L"Gesang der junglinge");
+  ios_base::iostate state1, state2;
+
+  wstringbuf isbuf_01(str_01, ios_base::in);
+  wistream is_01(&isbuf_01);
+
+  state1 = is_01.rdstate();
+  VERIFY( state1 == ios_base::goodbit );
+
+  is_01.ignore(11, L'j');
+  VERIFY( is_01.gcount() == 11 );
+  state2 = is_01.rdstate();
+  VERIFY( state2 == state1 );
+  VERIFY( is_01.peek() == L'j' );
+
+  is_01.ignore(9);
+  VERIFY( is_01.gcount() == 9 );
+  state2 = is_01.rdstate();
+  VERIFY( state2 == state1 );
+}
+
+int 
+main()
+{
+  test01();
+  return 0;
+}