Update.

* libio/bug-ungetwc1.c: New file.
	* libio/Makefile (tests): Add bug-ungetwc1.

	* libio/fileops.c (_IO_new_file_close_it): Only call _IO_do_flush
	if stream was last used for writing.

ChangeLog

@@ -1,5 +1,11 @@
 2002-04-02  Ulrich Drepper  <drepper@redhat.com>
 
+	* libio/bug-ungetwc1.c: New file.
+	* libio/Makefile (tests): Add bug-ungetwc1.
+
+	* libio/fileops.c (_IO_new_file_close_it): Only call _IO_do_flush
+	if stream was last used for writing.
+
 	* elf/do-lookup.h (do_lookup): 2 is the first user-defined version
 	number [PR libc/3111].
 

libio/Makefile

@@ -48,7 +48,8 @@ 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-ungetwc1 tst-ungetwc2 tst-swscanf tst-sscanf
+	tst-fgetws tst-ungetwc1 tst-ungetwc2 tst-swscanf tst-sscanf	      \
+	bug-ungetwc1
 test-srcs = test-freopen
 
 all: # Make this the default target; it will be defined in Rules.

libio/bug-ungetwc1.c

@@ -0,0 +1,74 @@
+#define _XOPEN_SOURCE 500
+#include <stdio.h>
+#include <stdlib.h>
+#include <locale.h>
+#include <wchar.h>
+
+const char write_chars[] = "ABC";      /* Characters on testfile. */
+const wint_t unget_wchar = L'A';      /* Ungotten wide character. */
+
+char *fname;
+
+
+static int do_test (void);
+#define TEST_FUNCTION do_test ()
+
+#include "../test-skeleton.c"
+
+
+static int
+do_test (void)
+{
+  wint_t wc;
+  FILE *fp;
+  int fd;
+
+  fname = (char *) malloc (strlen (test_dir) + sizeof "/bug-ungetwc1.XXXXXX");
+  if (fname == NULL)
+    {
+      puts ("no memory");
+      return 1;
+    }
+  strcpy (stpcpy (fname, test_dir), "/bug-ungetwc1.XXXXXX");
+  fd = mkstemp (fname);
+  if (fd == -1)
+    {
+      printf ("cannot open temporary file: %m\n");
+      return 1;
+    }
+
+  setlocale(LC_ALL, "");
+
+  /* Output to the file. */
+  if ((fp = fdopen (fd, "w")) == NULL)
+    {
+      fprintf (stderr, "Cannot make `%s' file\n", fname);
+      exit (EXIT_FAILURE);
+    }
+  add_temp_file (fname);
+
+  fprintf (fp, "%s", write_chars);
+  fclose (fp);
+
+  /* Read from the file. */
+  fp = fopen (fname, "r");
+
+  while (!feof (fp))
+    wc = getwc (fp);
+  printf ("\nThe end-of-file indicator is set.\n");
+
+  /* Unget a wide character. */
+  ungetwc (unget_wchar, fp);
+  printf ("< `%lc' is ungotten.\n", unget_wchar);
+
+  /* Check the end-of-file indicator. */
+  if (feof (fp))
+    printf ("The end-of-file indicator is still set.\n");
+  else
+    printf ("The end-of-file flag is cleared.\n");
+
+  fflush (stdout);
+  fclose (fp);
+
+  return 0;
+}

libio/fileops.c

@@ -161,7 +161,11 @@ _IO_new_file_close_it (fp)
   if (!_IO_file_is_open (fp))
     return EOF;
 
-  write_status = _IO_do_flush (fp);
+  if ((fp->_flags & _IO_NO_WRITES) == 0
+      && (fp->_flags & _IO_CURRENTLY_PUTTING) != 0)
+    write_status = _IO_do_flush (fp);
+  else
+    write_status = 0;
 
   INTUSE(_IO_unsave_markers) (fp);