Fix getttyname on Linux when called for different devices.

If a second call to ttyname is not for the same type of device (e.g.,
serial vs ptty) the prefix of the buffer was wrong.  Don't rely on
the previous content, always reinitialize it.

diff --git a/ChangeLog b/ChangeLog
index a169cee..25bb325 100644 (file)
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,8 +1,13 @@
 2009-10-29  Ulrich Drepper  <drepper@redhat.com>
 
+       [BZ #10784]
+       * sysdeps/unix/sysv/linux/ttyname.c (getttyname): Always copy name
+       of the directory we look at into the static buffer if there is one
+       at the start of the loop.
+
        [BZ #10789]
        * sysdeps/generic/netinet/ip.h: Define IPTOS_ENC* and IPTOS_DSCP*
-       macros.  Patch by  Philip Prindeville <philipp@redfish-solutions.com>.
+       macros.  Patch by Philip Prindeville <philipp@redfish-solutions.com>.
 
        [BZ #10840]
        * sysdeps/unix/sysv/linux/kernel-features.h: Define

diff --git a/sysdeps/unix/sysv/linux/ttyname.c b/sysdeps/unix/sysv/linux/ttyname.c
index 1b79787..69af6ad 100644 (file)
--- a/sysdeps/unix/sysv/linux/ttyname.c
+++ b/sysdeps/unix/sysv/linux/ttyname.c
@@ -1,4 +1,4 @@
-/* Copyright (C) 1991,92,93,1996-2002,2006 Free Software Foundation, Inc.
+/* Copyright (C) 1991,92,93,1996-2002,2006,2009 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
@@ -59,6 +59,11 @@ getttyname (const char *dev, dev_t mydev, ino64_t myino, int save, int *dostat)
       return NULL;
     }
 
+  /* Prepare for the loop.  If we already have a buffer copy the directory
+     name we look at into it.  */
+  if (devlen < namelen)
+    *((char *) __mempcpy (getttyname_name, dev, devlen - 1)) = '/';
+
   while ((d = __readdir64 (dirstream)) != NULL)
     if ((d->d_fileno == myino || *dostat)
        && strcmp (d->d_name, "stdin")