streambuf.tcc (__copy_streambufs): Revert previous fix for the interactive half…

streambuf.tcc (__copy_streambufs): Revert previous fix for the interactive half of libstdc++/6745...

2002-11-20  Benjamin Kosnik  <bkoz@redhat.com>
	    Jonathan Lennox  <lennox@cs.columbia.edu>

	* include/bits/streambuf.tcc (__copy_streambufs):
	Revert previous fix for the interactive half of
	libstdc++/6745, use _M_buf_size_opt to set dynamically
	the correct buffer size.

Co-Authored-By: Jonathan Lennox <lennox@cs.columbia.edu>

From-SVN: r59314

libstdc++-v3/ChangeLog

+2002-11-20  Benjamin Kosnik  <bkoz@redhat.com>
+            Jonathan Lennox  <lennox@cs.columbia.edu>
+
+	* include/bits/streambuf.tcc (__copy_streambufs):
+	Revert previous fix for the interactive half of
+	libstdc++/6745, use _M_buf_size_opt to set dynamically
+	the correct buffer size.
+
 2002-11-20  Jonathan Wakely  <redi@gcc.gnu.org>
 
 	* docs/html/21_strings/howto.html: Fix example code, cite Gaby's

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

@@ -37,10 +37,6 @@
 
 #pragma GCC system_header
 
-#ifdef _GLIBCPP_HAVE_UNISTD_H
-#include <unistd.h>
-#endif
-
 namespace std 
 {
   template<typename _CharT, typename _Traits>
@@ -224,11 +220,8 @@ namespace std
 		}
  	      else 
 		{
-#ifdef _GLIBCPP_HAVE_ISATTY		  
-		  size_t __size = isatty(0) ? 1 : static_cast<size_t>(BUFSIZ);
-#else
-		  size_t __size = 1;
-#endif
+		  size_t __size =
+		    __sbin->_M_buf_size_opt > 0 ? __sbin->_M_buf_size_opt : 1;
 		  _CharT* __buf =
 		    static_cast<_CharT*>(__builtin_alloca(sizeof(_CharT) * __size));
 		  streamsize __charsread = __sbin->sgetn(__buf, __size);