Add test for copy from empty file

Author: nikic

ext/standard/tests/file/stream_copy_to_stream_empty.phpt

@@ -0,0 +1,19 @@
+--TEST--
+stream_copy_to_stream() from empty file
+--FILE--
+<?php
+
+$tmp_empty_file = __FILE__ . ".tmp";
+file_put_contents($tmp_empty_file, "");
+
+$in = fopen($tmp_empty_file, 'r');
+$out = fopen('php://memory', 'w');
+var_dump(stream_copy_to_stream($in, $out));
+
+?>
+--CLEAN--
+<?php
+unlink(__FILE__ . ".tmp");
+?>
+--EXPECT--
+int(0)