[hurd,commited 4/4] hurd: Fix getxattr/listxattr returning ERANGE

[Samuel Thibault]

The manpage says that when the passed size is zero, they should set the
expected size and return 0. ERANGE shall be returned only when the non-zero
passed size is not large enough.
---
 hurd/xattr.c | 25 +++++++++++++++++++++----
 1 file changed, 21 insertions(+), 4 deletions(-)

diff --git a/hurd/xattr.c b/hurd/xattr.c
index 1a84c90db8..2d83edf2fe 100644
--- a/hurd/xattr.c
+++ b/hurd/xattr.c
@@ -50,7 +50,15 @@ _hurd_xattr_get (io_t port, const char *name, void *value, 
size_t *size)
       else if (value)
        {
          if (*size < sizeof st.st_author)
-           return ERANGE;
+           {
+             if (*size > 0)
+               return ERANGE;
+             else
+               {
+                 *size = sizeof st.st_author;
+                 return 0;
+               }
+           }
          memcpy (value, &st.st_author, sizeof st.st_author);
        }
       *size = sizeof st.st_author;
@@ -73,12 +81,21 @@ _hurd_xattr_get (io_t port, const char *name, void *value, 
size_t *size)
       err = __file_get_translator (port, &buf, &bufsz);
       if (err)
        return err;
-      if (value != NULL && *size < bufsz)
+
+      if (*size < bufsz)
        {
          if (buf != value)
            __munmap (buf, bufsz);
-         return ERANGE;
+
+         if (*size > 0)
+           return ERANGE;
+         else
+           {
+             *size = bufsz;
+             return 0;
+           }
        }
+
       if (buf != value && bufsz > 0)
        {
          if (value != NULL)
@@ -201,7 +218,7 @@ _hurd_xattr_list (io_t port, void *buffer, size_t *size)
   if (st.st_mode & S_IPTRANS)
     add ("gnu.translator");
 
-  if (buffer != NULL && total > *size)
+  if (*size > 0 && total > *size)
     return ERANGE;
   *size = total;
   return 0;
-- 
2.43.0