[v3, 3.4] Fix libstdc++/12077

[Paolo Carlini <pcarlini at suse dot de>]

Hi,

sorry: it occurred to me only today that fixing this bug requires adding
a member to class stdio_sync_filebuf.

Therefore, if nobody among the libstdc++ maintainers and contributors
disagree, I have to ask Mark permission for 3.4.0 too.

Actually, the patch is quite straighforward, IMO, since is a simplified
version of what is already in basic_filebuf.

Tested x86-linux.

Paolo.

////////////
2004-03-18  Paolo Carlini  <pcarlini@suse.de>

	PR libstdc++/12077
	* include/ext/stdio_sync_filebuf.h (_M_codecvt): New, cached
	codecvt facet.
	(stdio_sync_filebuf(std::__c_file*)): Initialize it.
	(showmanyc): Use it (same logic of basic_filebuf::showmanyc).
	(imbue(const std::locale&)): Sets it.
	* testsuite/ext/stdio_sync_filebuf/wchar_t/12077.cc: New.

diff -urN libstdc++-v3-orig/include/ext/stdio_sync_filebuf.h libstdc++-v3/include/ext/stdio_sync_filebuf.h
--- libstdc++-v3-orig/include/ext/stdio_sync_filebuf.h	2003-12-09 05:31:53.000000000 +0100
+++ libstdc++-v3/include/ext/stdio_sync_filebuf.h	2004-03-18 22:29:54.000000000 +0100
@@ -1,6 +1,6 @@
 // Iostreams wrapper for stdio FILE* -*- C++ -*-
 
-// Copyright (C) 2003 Free Software Foundation, Inc.
+// Copyright (C) 2003, 2004 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
@@ -37,6 +37,7 @@
 #pragma GCC system_header
 
 #include <streambuf>
+#include <locale>	// For codecvt
 #include <unistd.h>
 
 #if defined(_GLIBCXX_HAVE_S_ISREG) || defined(_GLIBCXX_HAVE_S_IFREG)
@@ -61,25 +62,35 @@
     {
     public:
       // Types:
-      typedef _CharT					char_type;
-      typedef _Traits					traits_type;
-      typedef typename traits_type::int_type		int_type;
-      typedef typename traits_type::pos_type		pos_type;
-      typedef typename traits_type::off_type		off_type;
+      typedef _CharT					   char_type;
+      typedef _Traits					   traits_type;
+      typedef typename traits_type::state_type             __state_type;
+      typedef typename traits_type::int_type		   int_type;
+      typedef typename traits_type::pos_type		   pos_type;
+      typedef typename traits_type::off_type		   off_type;
+
+      typedef std::codecvt<char_type, char, __state_type>  __codecvt_type;
 
     private:
       // Underlying stdio FILE
-      std::__c_file* const _M_file;
+      std::__c_file* const      _M_file;
 
       // Last character gotten. This is used when pbackfail is
       // called from basic_streambuf::sungetc()
-      int_type _M_unget_buf;
+      int_type                  _M_unget_buf;
+
+      // Cached codecvt facet.
+      const __codecvt_type* 	_M_codecvt;
 
     public:
       explicit
       stdio_sync_filebuf(std::__c_file* __f)
-      : _M_file(__f), _M_unget_buf(traits_type::eof())
-      { }
+      : _M_file(__f), _M_unget_buf(traits_type::eof()),
+	_M_codecvt(0)
+      {
+	if (std::has_facet<__codecvt_type>(this->_M_buf_locale))
+	  _M_codecvt = &std::use_facet<__codecvt_type>(this->_M_buf_locale);
+      }
 
     protected:
 
@@ -138,9 +149,14 @@
 #if defined(_GLIBCXX_HAVE_S_ISREG) || defined(_GLIBCXX_HAVE_S_IFREG)
 	// Regular files.
 	struct stat __buffer;
-	int __ret = fstat(fileno(_M_file), &__buffer);
-	if (!__ret && _GLIBCXX_ISREG(__buffer.st_mode))
-	  return __buffer.st_size - ftell(_M_file);
+
+	// For a stateful encoding (-1) the pending sequence might be just
+	// shift and unshift prefixes with no actual character.	
+	const int __ret = fstat(fileno(_M_file), &__buffer);
+	if (!__ret && _GLIBCXX_ISREG(__buffer.st_mode)
+	    && __check_facet(_M_codecvt).encoding() >= 0)
+	  return ((__buffer.st_size - ftell(_M_file))
+		  / _M_codecvt->max_length());
 #endif
 	return 0;
       }
@@ -195,6 +211,15 @@
 	      std::ios_base::openmode __mode =
 	      std::ios_base::in | std::ios_base::out)
       { return seekoff(std::streamoff(__pos), std::ios_base::beg, __mode); }
+
+      virtual void
+      imbue(const std::locale& __loc)
+      {
+	if (__builtin_expect(std::has_facet<__codecvt_type>(__loc), true))
+	  _M_codecvt = &std::use_facet<__codecvt_type>(__loc);
+	else
+	  _M_codecvt = 0;
+      }
     };
 
   template<>
diff -urN libstdc++-v3-orig/testsuite/ext/stdio_sync_filebuf/wchar_t/12077.cc libstdc++-v3/testsuite/ext/stdio_sync_filebuf/wchar_t/12077.cc
--- libstdc++-v3-orig/testsuite/ext/stdio_sync_filebuf/wchar_t/12077.cc	1970-01-01 01:00:00.000000000 +0100
+++ libstdc++-v3/testsuite/ext/stdio_sync_filebuf/wchar_t/12077.cc	2004-03-18 22:38:56.000000000 +0100
@@ -0,0 +1,81 @@
+// 2004-03-18 Petur Runolfsson <peturr02@ru.is>
+
+// Copyright (C) 2004 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.
+
+#include <iostream>
+#include <locale>
+#include <testsuite_hooks.h>
+
+// libstdc++/12077
+void test01()
+{
+  using namespace std;
+  bool test __attribute__((unused)) = true;
+
+  const char* name = "12077_tmp";
+
+  locale loc = __gnu_test::try_named_locale("is_IS.UTF-8");
+  locale::global(loc);
+  wcin.imbue(loc);
+
+  const char* str =
+    "\x1\x2\x3\x4\x5\x6\x7\x8\x9\xa\xb\xc\xd\xe\xf\x10\x11\x12\x13"
+    "\x14\x15\x16\x17\x18\x19\x1a\x1b\x1c\x1d\x1e\x1f\x20!\"#$%&"
+    "'()*+,-./0123456789:;<=>?@}~\x7f\xc2\x80\xc2\x81\xc2\x82\xc2"
+    "\x83\xc2\x84\xc2\x85\xc2\x86\xc2\x87\xc2\x88\xc2\x89\xc2\x8a"
+    "\xc2\x8b\xc2\x8c\xc2\x8d\xc2\x8e\xc2\x8f\xc2\x90\xc2\x91\xc2"
+    "\x92\xc2\x93\xc2\x94\xc2\x95\xc2\x96\xc2\x97\xc2\x98\xc2\x99"
+    "\xc2\x9a\xc2\x9b\xc2\x9c\xc3\xba\xc3\xbb\xc3\xbc\xc3\xbd\xc3"
+    "\xbe\xc3\xbf\xc4\x80\xc4\x81\xc4\x82\xc4\x83\xc4\x84\xc4\x85"
+    "\xc4\x86\xc4\x87\xc4\x88\xc4\x89\xc4\x8a\xc4\x8b\xc4\x8c\xc4"
+    "\x8d\xc4\x8e\xc4\x8f\xc4\x90\xc4\x91\xc4\x92\xc4\x93\xc4\x94"
+    "\xc4\x95\xc4\x96\xc4\x97\xc4\x98\xc4\x99\xdf\xb8\xdf\xb9\xdf"
+    "\xba\xdf\xbb\xdf\xbc\xdf\xbd\xdf\xbe\xdf\xbf\xe0\xa0\x80\xe0"
+    "\xa0\x81\xe0\xa0\x82\xe0\xa0\x83\xe0\xa0\x84\xe0\xa0\x85\xe0"
+    "\xa0\x86\xe0\xa0\x87\xe0\xa0\x88\xe0\xa0\x89\xe0\xa0\x8a\xe0"
+    "\xa0\x8b\xe0\xa0\x8c\xe0\xa0\x8d\xe0\xa0\x8e\xe0\xa0\x8f\xe0"
+    "\xa0\x90\xe0\xa0\x91\xe0\xa0\x92\xe0\xa0\x93\xe0\xa0\x94\xe0"
+    "\xa0\x95\xe0\xa0\x96\xe0\xa0\x97\x1\x2\x4\x8\x10\x20@\xc2\x80"
+    "\xc4\x80\xc8\x80\xd0\x80\xe0\xa0\x80\xe1\x80\x80\xe2\x80\x80"
+    "\xe4\x80\x80\xe8\x80\x80\xf0\x90\x80\x80\xf0\xa0\x80\x80\xf1"
+    "\x80\x80\x80\xf2\x80\x80\x80\xf4\x80\x80\x80\xf8\x88\x80\x80"
+    "\x80\xf8\x90\x80\x80\x80\xf8\xa0\x80\x80\x80\xf9\x80\x80\x80"
+    "\x80\xfa\x80\x80\x80\x80\xfc\x84\x80\x80\x80\x80\xfc\x88\x80"
+    "\x80\x80\x80\xfc\x90\x80\x80\x80\x80\xfc\xa0\x80\x80\x80\x80"
+    "\xfd\x80\x80\x80\x80\x80";
+
+  FILE* file = fopen(name, "w");
+  fputs(str, file);
+  fclose(file);
+  
+  freopen(name, "r", stdin);
+  
+  streamsize n = wcin.rdbuf()->in_avail();
+  while (n--)
+    {
+      wint_t c = wcin.rdbuf()->sbumpc();
+      VERIFY( c != WEOF );
+    }
+}
+
+int main()
+{
+  test01();
+  return 0;
+}