Adjust wide data buffer pointers during fseek and ftell

[BZ #14543]
Set the internal buffer state correctly whenever the external buffer
state is modified by fseek by either computing the current
_IO_read_ptr/end for the internal buffer based on the new _IO_read_ptr
in the external buffer or converting the content read into the
external buffer, up to the extent of the requested fseek offset.

1 files changed, 173 insertions, 0 deletions

diff --git a/libio/tst-fseek.c b/libio/tst-fseek.c
new file mode 100644
index 0000000000..457a087785
--- /dev/null
+++ b/libio/tst-fseek.c
@@ -0,0 +1,173 @@
+/* Verify that fseek/ftell combination works for wide chars.
+   Copyright (C) 2012 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+
+   The GNU C Library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Lesser General Public
+   License as published by the Free Software Foundation; either
+   version 2.1 of the License, or (at your option) any later version.
+
+   The GNU C 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
+   Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public
+   License along with the GNU C Library; if not, see
+   <http://www.gnu.org/licenses/>.  */
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <locale.h>
+#include <errno.h>
+#include <wchar.h>
+#include <unistd.h>
+#include <string.h>
+
+/* Defined in test-skeleton.c.  */
+static int create_temp_file (const char *base, char **filename);
+
+
+static int
+do_seek_end (FILE *fp)
+{
+  long save;
+
+  if (fputws (L"abc\n", fp) == -1)
+    {
+      printf ("do_seek_end: fputws: %s\n", strerror (errno));
+      return 1;
+    }
+
+  save = ftell (fp);
+  rewind (fp);
+
+  if (fseek (fp, 0, SEEK_END) == -1)
+    {
+      printf ("do_seek_end: fseek: %s\n", strerror (errno));
+      return 1;
+    }
+
+  if (save != ftell (fp))
+    {
+      printf ("save = %ld, ftell = %ld\n", save, ftell (fp));
+      return 1;
+    }
+
+  return 0;
+}
+
+int
+do_seek_set (FILE *fp)
+{
+  long save1, save2;
+
+  if (fputws (L"ゅう\n", fp) == -1)
+    {
+      printf ("seek_set: fputws(1): %s\n", strerror (errno));
+      return 1;
+    }
+
+  save1 = ftell (fp);
+
+  if (fputws (L"ゅう\n", fp) == -1)
+    {
+      printf ("seek_set: fputws(2): %s\n", strerror (errno));
+      return 1;
+    }
+
+  save2 = ftell (fp);
+
+  if (fputws (L"ゅう\n", fp) == -1)
+    {
+      printf ("seek_set: fputws(3): %s\n", strerror (errno));
+      return 1;
+    }
+
+  if (fseek (fp, save1, SEEK_SET) == -1)
+    {
+      printf ("seek_set: fseek(1): %s\n", strerror (errno));
+      return 1;
+    }
+
+  if (save1 != ftell (fp))
+    {
+      printf ("save1 = %ld, ftell = %ld\n", save1, ftell (fp));
+      return 1;
+    }
+
+  if (fseek (fp, save2, SEEK_SET) == -1)
+    {
+      printf ("seek_set: fseek(2): %s\n", strerror (errno));
+      return 1;
+    }
+
+  if (save2 != ftell (fp))
+    {
+      printf ("save2 = %ld, ftell = %ld\n", save2, ftell (fp));
+      return 1;
+    }
+
+  return 0;
+}
+
+static int
+do_test (void)
+{
+  if (setlocale (LC_ALL, "ja_JP.UTF-8") == NULL)
+    {
+      printf ("Cannot set ja_JP.UTF-8 locale.\n");
+      exit (1);
+    }
+
+  /* Retain messages in English.  */
+  if (setlocale (LC_MESSAGES, "en_US.ISO-8859-1") == NULL)
+    {
+      printf ("Cannot set LC_MESSAGES to en_US.ISO-8859-1 locale.\n");
+      exit (1);
+    }
+
+  int ret = 0;
+  char *filename;
+  int fd = create_temp_file ("tst-fseek.out", &filename);
+
+  if (fd == -1)
+    return 1;
+
+  FILE *fp = fdopen (fd, "w+");
+  if (fp == NULL)
+    {
+      printf ("seek_set: fopen: %s\n", strerror (errno));
+      close (fd);
+      return 1;
+    }
+
+  if (do_seek_set (fp))
+    {
+      printf ("SEEK_SET test failed\n");
+      ret = 1;
+    }
+
+  /* Reopen the file.  */
+  fclose (fp);
+  fp = fopen (filename, "w+");
+  if (fp == NULL)
+    {
+      printf ("seek_end: fopen: %s\n", strerror (errno));
+      return 1;
+    }
+
+  if (do_seek_end (fp))
+    {
+      printf ("SEEK_END test failed\n");
+      ret = 1;
+    }
+
+  fclose (fp);
+
+  return ret;
+}
+
+
+#define TEST_FUNCTION do_test ()
+#include "../test-skeleton.c"