fstream.tcc (basic_filebuf::seekoff): Fix for output-only filebufs.

        * include/bits/fstream.tcc (basic_filebuf::seekoff): Fix for
        output-only filebufs.
        * include/std/std_fstream.h (basic_filebuf::_M_set_indeterminate):
        Likewise.
        (basic_filebuf::_M_set_determinate): Likewise.

From-SVN: r52685

libstdc++-v3/ChangeLog

 2002-04-23  Jason Merrill  <jason@redhat.com>
 
+	* include/bits/fstream.tcc (basic_filebuf::seekoff): Fix for
+	output-only filebufs.
+	* include/std/std_fstream.h (basic_filebuf::_M_set_indeterminate):
+	Likewise.
+	(basic_filebuf::_M_set_determinate): Likewise.
+
 	PR libstdc++/6414
 	* include/bits/fstream.tcc (basic_filebuf::seekoff): Adjust return
 	value properly in the trivial case.

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

@@ -567,7 +567,7 @@ namespace std
 	  else
 	    {
 	      __ret = _M_file.seekoff(__off, ios_base::cur, __mode);
-	      __ret += _M_in_cur - _M_filepos;
+	      __ret += max(_M_out_cur, _M_in_cur) - _M_filepos;
 	    }
 	}
       _M_last_overflowed = false;	

libstdc++-v3/include/std/std_fstream.h

@@ -264,7 +264,7 @@ namespace std
 	  this->setg(_M_buf, _M_buf, _M_buf);
 	if (_M_mode & ios_base::out)
 	  this->setp(_M_buf, _M_buf);
-	_M_filepos = _M_in_end;
+	_M_filepos = _M_buf;
       }
 
       void
@@ -276,7 +276,7 @@ namespace std
 	  this->setg(_M_buf, _M_buf, _M_buf + __off);
 	if (__testout)
 	  this->setp(_M_buf, _M_buf + __off);
-	_M_filepos = _M_in_end;
+	_M_filepos = _M_buf + __off;
       }
 
       bool

libstdc++-v3/testsuite/27_io/ostream_seeks.cc

@@ -167,6 +167,13 @@ void test04(void)
   pos06 = is03.tellp(); 
   VERIFY( pos05 == pos06 ); 
 
+  // libstdc++/6414
+  if01.seekg(0, std::ios_base::beg);
+  pos01 = if01.tellg();
+  if01.peek();
+  pos02 = if01.tellg();
+  VERIFY( pos02 == pos01 );
+
 #ifdef DEBUG_ASSERT
   assert(test);
 #endif