Description:
------------
When destination folder of a copy haven't enough place, copy reports success instead of failure.


Test script:
---------------
<?php
$file = "somefile";
$tmpdir = "/mnt/test/";

echo "Source: ".($src=filesize($file))."\n";

for ($i=0 ; $i<7 ; $i++) {
  $res = copy($file, $tmpdir.$i);
  $dst = filesize($tmpdir.$i);
  echo "$i:".($res ? ($dst==$src ? "ok" : "ISSUE ($dst/$src)") : "ko")."\n";
}


Expected result:
----------------
Source: 107520
0:ok
1:ok
2:ok
3:ok
4:ko
5:ko
6:ko


Actual result:
--------------
Source: 107520
0:ok
1:ok
2:ok
3:ok
4:ISSUE (49152/107520)
5:ko
6:ko