Update.

* io/ftw.c (ftw_dir): Don't add a second slash at the beginning
	for searches from the root directory.
	Reported by loris <loris@iol.it> [PR libc/1991].
	* io/Makefile (tests): Add bug-ftw1.
	* io/bug-ftw1.c: New file.

ChangeLog

@@ -1,5 +1,11 @@
 2001-01-05  Ulrich Drepper  <drepper@redhat.com>
 
+	* io/ftw.c (ftw_dir): Don't add a second slash at the beginning
+	for searches from the root directory.
+	Reported by loris <loris@iol.it> [PR libc/1991].
+	* io/Makefile (tests): Add bug-ftw1.
+	* io/bug-ftw1.c: New file.
+
 	* elf/dl-support.c (non_dynamic_init): Don't define DL_FIND_AUXV
 	if it is not available.  Instead use it only if it is available.
 	* sysdeps/unix/sysv/linux/ldsodefs.h: New file.

io/Makefile

@@ -1,4 +1,4 @@
-# Copyright (C) 1992-1999, 2000 Free Software Foundation, Inc.
+# Copyright (C) 1992-1999, 2000, 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
@@ -56,7 +56,7 @@ static-only-routines = stat fstat lstat mknod stat64 fstat64 lstat64
 others		:= pwd
 test-srcs	:= ftwtest
 tests		:= test-utime test-stat test-stat2 test-lfs tst-getcwd \
-		   tst-fcntl
+		   tst-fcntl bug-ftw1
 
 distribute	:= ftwtest-sh
 

io/bug-ftw1.c

@@ -0,0 +1,78 @@
+/* Test for ftw function searching in root directory.
+   Copyright (C) 2001 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+   Contributed by Ulrich Drepper <drepper@cygnus.com>, 2001.
+
+   The GNU C Library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Library General Public License as
+   published by the Free Software Foundation; either version 2 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
+   Library General Public License for more details.
+
+   You should have received a copy of the GNU Library General Public
+   License along with the GNU C Library; see the file COPYING.LIB.  If not,
+   write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
+   Boston, MA 02111-1307, USA.  */
+
+#include <ftw.h>
+#include <mcheck.h>
+#include <stdio.h>
+#include <string.h>
+
+
+int result;
+int cnt;
+int sawroot;
+
+
+static int
+callback (const char *fname, const struct stat *st, int flag)
+{
+  if (++cnt >= 10)
+    return 1;
+
+  printf ("%d: \"%s\" -> ", cnt, fname);
+  if (strcmp (fname, "/") == 0 && sawroot)
+    {
+      puts ("root directory reported twice");
+      result = 1;
+    }
+  else if (fname[0] != '/')
+    {
+      puts ("missing '/' as first character");
+      result = 1;
+    }
+  else if (fname[1] == '/')
+    {
+      puts ("double '/' at beginning");
+      result = 1;
+    }
+  else
+    {
+      puts ("OK");
+      sawroot |= strcmp (fname, "/") == 0;
+    }
+
+  return 0;
+}
+
+
+int
+main (void)
+{
+  mtrace ();
+
+  ftw ("/", callback, 10);
+
+  if (! sawroot)
+    {
+      puts ("root directory wasn't reported");
+      result = 1;
+    }
+
+  return result;
+}

io/ftw.c

@@ -1,5 +1,5 @@
 /* File tree walker functions.
-   Copyright (C) 1996, 1997, 1998, 1999, 2000 Free Software Foundation, Inc.
+   Copyright (C) 1996,1997,1998,1999,2000,2001 Free Software Foundation, Inc.
    This file is part of the GNU C Library.
    Contributed by Ulrich Drepper <drepper@cygnus.com>, 1996.
 
@@ -396,7 +396,10 @@ ftw_dir (struct ftw_data *data, struct STAT *st)
   /* Next, update the `struct FTW' information.  */
   ++data->ftw.level;
   startp = strchr (data->dirbuf, '\0');
-  *startp++ = '/';
+  /* There always must be a directory name.  */
+  assert (startp != data->dirbuf);
+  if (startp != data->dirbuf + 1)
+    *startp++ = '/';
   data->ftw.base = startp - data->dirbuf;
 
   while (dir.stream != NULL && (d = READDIR (dir.stream)) != NULL)