--- /dev/null
+// 2001-05-21 Benjamin Kosnik <bkoz@redhat.com>
+
+// Copyright (C) 2001, 2002, 2003, 2009 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 3, 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 COPYING3. If not see
+// <http://www.gnu.org/licenses/>.
+
+// 27.8.1.4 Overridden virtual functions
+
+// { dg-require-fileio "" }
+
+#include <fstream>
+#include <testsuite_hooks.h>
+
+const char name_06[] = "filebuf_virtuals-6.txt"; // empty file, need to create
+
+// libstdc++/9825
+// filebuf::sputbackc breaks sbumpc
+void test12()
+{
+ using namespace std;
+ bool test __attribute__((unused)) = true;
+
+ filebuf fbuf;
+
+ fbuf.open(name_06, ios_base::in|ios_base::out|ios_base::trunc);
+ fbuf.sputn("crazy bees!", 11);
+ fbuf.pubseekoff(0, ios_base::beg);
+ fbuf.sbumpc();
+ fbuf.sputbackc('x');
+ filebuf::int_type c = fbuf.sbumpc();
+ VERIFY( c == 'x' );
+ c = fbuf.sbumpc();
+ VERIFY( c == 'r' );
+ c = fbuf.sbumpc();
+ VERIFY( c == 'a' );
+ fbuf.close();
+}
+
+int main()
+{
+ test12();
+ return 0;
+}