[glibc] hurd: Fix getxattr("gnu.translator") returning ENODATA

[glibc] hurd: Fix getxattr("gnu.translator") returning ENODATA

[Samuel Thibault]

https://sourceware.org/git/gitweb.cgi?p=glibc.git;h=ba5a23422a156804234dff6c5be89e20ee8f9ec2

commit ba5a23422a156804234dff6c5be89e20ee8f9ec2
Author: Samuel Thibault <samuel.thibault@ens-lyon.org>
Date:   Mon Jun 10 21:57:53 2024 +0200

    hurd: Fix getxattr("gnu.translator") returning ENODATA
    
    When no translator is set, __file_get_translator would return EINVAL
    which is a confusing value. Better check for a passive translation
    before getting the value.

Diff:
---
 hurd/xattr.c | 11 ++++++++++-
 1 file changed, 10 insertions(+), 1 deletion(-)

diff --git a/hurd/xattr.c b/hurd/xattr.c
index 0715ad7b02..f613d47c83 100644
--- a/hurd/xattr.c
+++ b/hurd/xattr.c
@@ -61,7 +61,16 @@ _hurd_xattr_get (io_t port, const char *name, void *value, size_t *size)
     {
       char *buf = value;
       mach_msg_type_number_t bufsz = value ? *size : 0;
-      error_t err = __file_get_translator (port, &buf, &bufsz);
+      struct stat64 st;
+      error_t err;
+
+      err = __io_stat (port, &st);
+      if (err)
+	return err;
+      if ((st.st_mode & S_IPTRANS) == 0)
+	return ENODATA;
+
+      err = __file_get_translator (port, &buf, &bufsz);
       if (err)
 	return err;
       if (value != NULL && *size < bufsz)