Update.

* libio/ioungetwc.c (ungetwc): Orient stream first.
	* libio/Makefile (tests): Add tst-ungetwc1.
	* libio/tst-ungetwc1.c: New file.

ChangeLog

@@ -1,5 +1,9 @@
 2001-08-08  Ulrich Drepper  <drepper@redhat.com>
 
+	* libio/ioungetwc.c (ungetwc): Orient stream first.
+	* libio/Makefile (tests): Add tst-ungetwc1.
+	* libio/tst-ungetwc1.c: New file.
+
 	* libio/wfileops.c (_IO_wfile_underflow): Remove incorrect test
 	for possible conversion using __codecvt_do_in.
 	* libio/Makefile (tests): Add tst-fgetws.

libio/Makefile

@@ -48,7 +48,7 @@ routines	:=							      \
 
 tests = tst_swprintf tst_wprintf tst_swscanf tst_wscanf tst_getwc tst_putwc   \
 	tst_wprintf2 tst-widetext test-fmemopen tst-ext tst-fopenloc	      \
-	tst-fgetws
+	tst-fgetws tst-ungetwc1
 test-srcs = test-freopen
 
 all: # Make this the default target; it will be defined in Rules.
@@ -83,7 +83,8 @@ tst_wprintf2-ARGS = "Some Text"
 tst-widetext-ENV = LOCPATH=$(common-objpfx)localedata LANGUAGE=C
 tst-fopenloc-ENV = LOCPATH=$(common-objpfx)localedata \
 		   MALLOC_TRACE=$(objpfx)tst-fopenloc.mtrace
-tst-fgetws-ENV = LOCPATH=$(common-objpfx)localedata LANGUAGE=C
+tst-fgetws-ENV = LOCPATH=$(common-objpfx)localedata
+tst-ungetwc1-ENV = LOCPATH=$(common-objpfx)localedata
 
 generated = tst-fopenloc.mtrace tst-fopenloc.check
 

libio/ioungetwc.c

@@ -1,4 +1,4 @@
-/* Copyright (C) 1993, 1996, 1997, 1998, 1999 Free Software Foundation, Inc.
+/* Copyright (C) 1993, 1996-1999, 2001 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
@@ -35,11 +35,13 @@ ungetwc (c, fp)
 {
   int result;
   CHECK_FILE (fp, WEOF);
-  if (c == WEOF)
-    return WEOF;
   _IO_cleanup_region_start ((void (*) __P ((void *))) _IO_funlockfile, fp);
   _IO_flockfile (fp);
-  result = _IO_sputbackwc (fp, c);
+  _IO_fwide (fp, 1);
+  if (c == WEOF)
+    result = WEOF;
+  else
+    result = _IO_sputbackwc (fp, c);
   _IO_funlockfile (fp);
   _IO_cleanup_region_end (0);
   return result;

libio/tst-ungetwc1.c

@@ -0,0 +1,81 @@
+/* Taken from the Li18nux base test suite.  */
+
+#define _XOPEN_SOURCE 500
+#include <locale.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <unistd.h>
+#include <wchar.h>
+
+int
+main (void)
+{
+  FILE *fp;
+  char *str ="abcdef";
+  wint_t ret, wc, ungetone = 0x00E4;	/* 0x00E4 means `a umlaut'. */
+  char fname[] = "/tmp/tst-ungetwc1.out.XXXXXX";
+  int fd;
+  int result = 0;
+
+  puts ("This program runs on de_DE.UTF-8 locale.");
+  if (setlocale (LC_ALL, "de_DE.UTF-8") == NULL)
+    {
+      fprintf (stderr, "Err: Cannot run on the de_DE.UTF-8 locale");
+      exit (EXIT_FAILURE);
+    }
+
+  fd = mkstemp (fname);
+  if (fd == -1)
+    {
+      printf ("cannot open temp file: %m\n");
+      exit (EXIT_FAILURE);
+    }
+
+  /* Write some characters to `testfile'. */
+  if ((fp = fdopen (fd, "w")) == NULL)
+    {
+      fprintf (stderr, "Cannot open 'testfile'.");
+      exit (EXIT_FAILURE);
+    }
+  fputs (str, fp);
+  fclose (fp);
+
+  /* Open `testfile'. */
+  if ((fp = fopen (fname, "r")) == NULL)
+    {
+      fprintf (stderr, "Cannot open 'testfile'.");
+      exit (EXIT_FAILURE);
+    }
+
+  /* Unget a character. */
+  ret = ungetwc (ungetone, fp);
+  printf ("Unget a character (0x%04x)\n", (unsigned int) ungetone);
+  fflush (stdout);
+  if (ret == WEOF)
+    {
+      puts ("ungetwc() returns NULL.");
+      exit (EXIT_SUCCESS);
+    }
+
+  /* Reget a character. */
+  wc = getwc (fp);
+  printf ("Reget a character (0x%04x)\n", (unsigned int) wc);
+  fflush (stdout);
+  if (wc == ungetone)
+    {
+      puts ("The ungotten character is equal to the regotten character.");
+      fflush (stdout);
+    }
+  else
+    {
+      puts ("The ungotten character is not equal to the regotten character.");
+      printf ("ungotten one: %04x, regetone: %04x", ungetone, wc);
+      fflush (stdout);
+      result = 1;
+    }
+  fclose (fp);
+
+  unlink (fname);
+
+  return result;
+}