error, warn, warnx: Use __fxprintf for wide printing [BZ #23519]

diff --git a/include/stdio.h b/include/stdio.h
index 9162d4e247..49383fb2d7 100644
--- a/include/stdio.h
+++ b/include/stdio.h
@@ -126,6 +126,8 @@  extern int __fxprintf (FILE *__fp, const char *__fmt, ...)
      __attribute__ ((__format__ (__printf__, 2, 3))) attribute_hidden;
 extern int __fxprintf_nocancel (FILE *__fp, const char *__fmt, ...)
      __attribute__ ((__format__ (__printf__, 2, 3))) attribute_hidden;
+int __vfxprintf (FILE *__fp, const char *__fmt, __gnuc_va_list)
+  attribute_hidden;
 
 /* Read the next line from FP into BUFFER, of LENGTH bytes.  LINE will
    include the line terminator and a NUL terminator.  On success,
diff --git a/misc/err.c b/misc/err.c
index 2b836e8358..790ee127d5 100644
--- a/misc/err.c
+++ b/misc/err.c
@@ -37,68 +37,14 @@  extern char *__progname;
   va_end (ap);								      \
 }
 
-static void
-convert_and_print (const char *format, __gnuc_va_list ap)
-{
-#define ALLOCA_LIMIT	2000
-  size_t len;
-  wchar_t *wformat = NULL;
-  mbstate_t st;
-  size_t res;
-  const char *tmp;
-
-  if (format == NULL)
-    return;
-
-  len = strlen (format) + 1;
-
-  do
-    {
-      if (len < ALLOCA_LIMIT)
-	wformat = (wchar_t *) alloca (len * sizeof (wchar_t));
-      else
-	{
-	  if (wformat != NULL && len / 2 < ALLOCA_LIMIT)
-	    wformat = NULL;
-
-	  wformat = (wchar_t *) realloc (wformat, len * sizeof (wchar_t));
-
-	  if (wformat == NULL)
-	    {
-	      fputws_unlocked (L"out of memory\n", stderr);
-	      return;
-	    }
-	}
-
-      memset (&st, '\0', sizeof (st));
-      tmp =format;
-    }
-  while ((res = __mbsrtowcs (wformat, &tmp, len, &st)) == len);
-
-  if (res == (size_t) -1)
-    /* The string cannot be converted.  */
-    wformat = (wchar_t *) L"???";
-
-  __vfwprintf (stderr, wformat, ap);
-}
-
 void
 vwarnx (const char *format, __gnuc_va_list ap)
 {
   flockfile (stderr);
-  if (_IO_fwide (stderr, 0) > 0)
-    {
-      __fwprintf (stderr, L"%s: ", __progname);
-      convert_and_print (format, ap);
-      putwc_unlocked (L'\n', stderr);
-    }
-  else
-    {
-      fprintf (stderr, "%s: ", __progname);
-      if (format)
-	vfprintf (stderr, format, ap);
-      putc_unlocked ('\n', stderr);
-    }
+  __fxprintf (stderr, "%s: ", __progname);
+  if (format)
+    __vfxprintf (stderr, format, ap);
+  __fxprintf (stderr, "\n");
   funlockfile (stderr);
 }
 libc_hidden_def (vwarnx)
@@ -109,28 +55,14 @@  vwarn (const char *format, __gnuc_va_list ap)
   int error = errno;
 
   flockfile (stderr);
-  if (_IO_fwide (stderr, 0) > 0)
+  __fxprintf (stderr, "%s: ", __progname);
+  if (format)
     {
-      __fwprintf (stderr, L"%s: ", __progname);
-      if (format)
-	{
-	  convert_and_print (format, ap);
-	  fputws_unlocked (L": ", stderr);
-	}
-      __set_errno (error);
-      __fwprintf (stderr, L"%m\n");
-    }
-  else
-    {
-      fprintf (stderr, "%s: ", __progname);
-      if (format)
-	{
-	  vfprintf (stderr, format, ap);
-	  fputs_unlocked (": ", stderr);
-	}
-      __set_errno (error);
-      fprintf (stderr, "%m\n");
+      __vfxprintf (stderr, format, ap);
+      fputs_unlocked (": ", stderr);
     }
+  __set_errno (error);
+  __fxprintf (stderr, "%m\n");
   funlockfile (stderr);
 }
 libc_hidden_def (vwarn)
diff --git a/misc/error.c b/misc/error.c
index 03378e2f2a..cb0de3af28 100644
--- a/misc/error.c
+++ b/misc/error.c
@@ -203,72 +203,14 @@  static void _GL_ATTRIBUTE_FORMAT_PRINTF (3, 0) _GL_ARG_NONNULL ((3))
 error_tail (int status, int errnum, const char *message, va_list args)
 {
 #if _LIBC
-  if (_IO_fwide (stderr, 0) > 0)
-    {
-      size_t len = strlen (message) + 1;
-      wchar_t *wmessage = NULL;
-      mbstate_t st;
-      size_t res;
-      const char *tmp;
-      bool use_malloc = false;
-
-      while (1)
-	{
-	  if (__libc_use_alloca (len * sizeof (wchar_t)))
-	    wmessage = (wchar_t *) alloca (len * sizeof (wchar_t));
-	  else
-	    {
-	      if (!use_malloc)
-		wmessage = NULL;
-
-	      wchar_t *p = (wchar_t *) realloc (wmessage,
-						len * sizeof (wchar_t));
-	      if (p == NULL)
-		{
-		  free (wmessage);
-		  fputws_unlocked (L"out of memory\n", stderr);
-		  return;
-		}
-	      wmessage = p;
-	      use_malloc = true;
-	    }
-
-	  memset (&st, '\0', sizeof (st));
-	  tmp = message;
-
-	  res = mbsrtowcs (wmessage, &tmp, len, &st);
-	  if (res != len)
-	    break;
-
-	  if (__builtin_expect (len >= SIZE_MAX / sizeof (wchar_t) / 2, 0))
-	    {
-	      /* This really should not happen if everything is fine.  */
-	      res = (size_t) -1;
-	      break;
-	    }
-
-	  len *= 2;
-	}
-
-      if (res == (size_t) -1)
-	{
-	  /* The string cannot be converted.  */
-	  if (use_malloc)
-	    {
-	      free (wmessage);
-	      use_malloc = false;
-	    }
-	  wmessage = (wchar_t *) L"???";
-	}
-
-      __vfwprintf (stderr, wmessage, args);
-
-      if (use_malloc)
-	free (wmessage);
-    }
-  else
+  int ret = __vfxprintf (stderr, message, args);
+  if (ret < 0 && errno == ENOMEM && _IO_fwide (stderr, 0) > 0)
+    /* Leave a trace in case the heap allocation of the message string
+       failed.  */
+    fputws_unlocked (L"out of memory\n", stderr);
+#else
+  vfprintf (stderr, message, args);
 #endif
-    vfprintf (stderr, message, args);
   va_end (args);
 
   ++error_message_count;
diff --git a/stdio-common/fxprintf.c b/stdio-common/fxprintf.c
index c4a1146b20..8d02b71f91 100644
--- a/stdio-common/fxprintf.c
+++ b/stdio-common/fxprintf.c
@@ -61,19 +61,23 @@  locked_vfxprintf (FILE *fp, const char *fmt, va_list ap)
   return res;
 }
 
+int
+__vfxprintf (FILE *fp, const char *fmt, va_list ap)
+{
+  if (fp == NULL)
+    fp = stderr;
+  _IO_flockfile (fp);
+  int res = locked_vfxprintf (fp, fmt, ap);
+  _IO_funlockfile (fp);
+  return res;
+}
+
 int
 __fxprintf (FILE *fp, const char *fmt, ...)
 {
-  if (fp == NULL)
-    fp = stderr;
-
   va_list ap;
   va_start (ap, fmt);
-  _IO_flockfile (fp);
-
-  int res = locked_vfxprintf (fp, fmt, ap);
-
-  _IO_funlockfile (fp);
+  int res = __vfxprintf (fp, fmt, ap);
   va_end (ap);
   return res;
 }