stdio_filebuf.h (stdio_filebuf::stdio_filebuf(...), ...): _M_buf_size_opt == 0 means only...

2003-04-12  Paolo Carlini  <pcarlini at unitus dot it>

	* include/ext/stdio_filebuf.h
	(stdio_filebuf::stdio_filebuf(int, openmode, bool, size_t),
	stdio_filebuf::stdio_filebuf(__c_file*, openmode, size_t):
	_M_buf_size_opt == 0 means only "not to use an allocated buffer"
	since a stack-based buffer is used for small values of the size_t
	parameter.
	* include/bits/fstream.tcc (basic_filebuf::_M_really_overflow).
	If _M_buf_size != 0 flush out the buffer (any kind, stack-based too).
	* testsuite/ext/stdio_filebuf_2.cc: New testfile.

From-SVN: r65513

4 files changed, 76 insertions, 3 deletions

diff --git a/libstdc++-v3/ChangeLog b/libstdc++-v3/ChangeLog
index 03b3077..65197a2 100644
--- a/libstdc++-v3/ChangeLog
+++ b/libstdc++-v3/ChangeLog
@@ -1,3 +1,15 @@
+2003-04-12  Paolo Carlini  <pcarlini at unitus dot it>
+
+	* include/ext/stdio_filebuf.h
+	(stdio_filebuf::stdio_filebuf(int, openmode, bool, size_t),
+	stdio_filebuf::stdio_filebuf(__c_file*, openmode, size_t):
+	_M_buf_size_opt == 0 only means "not to use an allocated buffer"
+	since a stack-based buffer is used for small values of the size_t
+	parameter.
+	* include/bits/fstream.tcc (basic_filebuf::_M_really_overflow).
+	If _M_buf_size != 0 flush out the buffer (any kind, stack-based too).
+	* testsuite/ext/stdio_filebuf_2.cc: New testfile.
+
 2003-04-12  Paolo Carlini  <pcarlini@unitus.it>
 
 	PR libstdc++/9533
diff --git a/libstdc++-v3/include/bits/fstream.tcc b/libstdc++-v3/include/bits/fstream.tcc
index 64f5d1d..c4481ba 100644
--- a/libstdc++-v3/include/bits/fstream.tcc
+++ b/libstdc++-v3/include/bits/fstream.tcc
@@ -355,7 +355,7 @@ namespace std
     {
       int_type __ret = traits_type::eof();
       bool __testput = this->_M_out_cur && this->_M_out_beg < this->_M_out_lim;
-      bool __testunbuffered = _M_file.is_open() && !this->_M_buf_size_opt;
+      bool __testunbuffered = _M_file.is_open() && !this->_M_buf_size;
       // Sync with stdio.
       bool __sync = this->_M_buf_size <= 1;
 
diff --git a/libstdc++-v3/include/ext/stdio_filebuf.h b/libstdc++-v3/include/ext/stdio_filebuf.h
index c412564..b15d8d8 100644
--- a/libstdc++-v3/include/ext/stdio_filebuf.h
+++ b/libstdc++-v3/include/ext/stdio_filebuf.h
@@ -126,7 +126,7 @@ namespace __gnu_cxx
 	  this->_M_mode = __mode;
 	  if (__size > 0 && __size < 4)
 	    {
-	      // Specify unbuffered.
+	      // Specify not to use an allocated buffer.
 	      this->_M_buf = _M_unbuf;
 	      this->_M_buf_size = __size;
 	      this->_M_buf_size_opt = 0;
@@ -151,7 +151,7 @@ namespace __gnu_cxx
 	  this->_M_mode = __mode;
 	  if (__size > 0 && __size < 4)
 	    {
-	      // Specify unbuffered.
+	      // Specify not to use an allocated buffer.
 	      this->_M_buf = _M_unbuf;
 	      this->_M_buf_size = __size;
 	      this->_M_buf_size_opt = 0;
diff --git a/libstdc++-v3/testsuite/ext/stdio_filebuf_2.cc b/libstdc++-v3/testsuite/ext/stdio_filebuf_2.cc
new file mode 100644
index 0000000..b4b30c6
--- /dev/null
+++ b/libstdc++-v3/testsuite/ext/stdio_filebuf_2.cc
@@ -0,0 +1,61 @@
+// 2003-04-12  Paolo Carlini  <pcarlini at unitus dot it>
+
+// Copyright (C) 2003 Free Software Foundation, Inc.
+//
+// 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.
+
+// stdio_filebuf.h
+
+#include <ext/stdio_filebuf.h>
+#include <cstdio>
+#include <fstream>
+#include <testsuite_hooks.h>
+
+// Small stack-based buffers (i.e., using _M_unbuf) were not flushed
+// out by _M_really_overflow upon overflow.
+void test01()
+{
+  
+  using namespace std;
+  bool test = true;
+
+  const char* name = "tmp_file1";
+  FILE* file = fopen(name, "w");
+  {
+    using namespace __gnu_cxx;
+    
+    // One char big stack-based buffer.
+    stdio_filebuf<char> sbuf(file, ios_base::out, 1); 
+    sbuf.sputc('T');
+    sbuf.sputc('S');
+  }
+  fclose(file);
+
+  filebuf fbuf;
+  fbuf.open(name, ios_base::in);
+  char buf[10];
+  streamsize n = fbuf.sgetn(buf, sizeof(buf));	
+  fbuf.close();
+  
+  VERIFY( n == 2 );
+  VERIFY( !memcmp(buf, "TS", 2) );
+}
+
+int main()
+{
+  test01();
+}