Fix fsetpos on wide stream.

libio/bug-wsetpos.c

@@ -0,0 +1,75 @@
+/* Test program for fsetpos on a wide character stream.  */
+
+#include <assert.h>
+#include <stdio.h>
+#include <wchar.h>
+
+static void do_prepare (void);
+#define PREPARE(argc, argv) do_prepare ()
+static int do_test (void);
+#define TEST_FUNCTION do_test ()
+#include <test-skeleton.c>
+
+static const char pattern[] = "12345";
+static char *temp_file;
+
+static void
+do_prepare (void)
+{
+  int fd = create_temp_file ("bug-wsetpos.", &temp_file);
+  if (fd == -1)
+    {
+      printf ("cannot create temporary file: %m\n");
+      exit (1);
+    }
+  write (fd, pattern, sizeof (pattern));
+  close (fd);
+}
+
+static int
+do_test (void)
+{
+  FILE *fp = fopen (temp_file, "r");
+  fpos_t pos;
+  wchar_t c;
+
+  if (fp == NULL)
+    {
+      printf ("fdopen: %m\n");
+      return 1;
+    }
+
+  c = fgetwc (fp); assert (c == L'1');
+  c = fgetwc (fp); assert (c == L'2');
+
+  if (fgetpos (fp, &pos) == EOF)
+    {
+      printf ("fgetpos: %m\n");
+      return 1;
+    }
+
+  rewind (fp);
+  if (ferror (fp))
+    {
+      printf ("rewind: %m\n");
+      return 1;
+    }
+
+  c = fgetwc (fp); assert (c == L'1');
+
+  if (fsetpos (fp, &pos) == EOF)
+    {
+      printf ("fsetpos: %m\n");
+      return 1;
+    }
+
+  c = fgetwc (fp);
+  if (c != L'3')
+    {
+      puts ("fsetpos failed");
+      return 1;
+    }
+
+  puts ("Test succeeded.");
+  return 0;
+}