Description:
------------
There's a tar file that PharData fails to open: http://download.pear.php.net/package/Structures_Graph-1.1.1.tgz (either gzipped or ungzipped).

It works with php 5.3 (vanilla), 5.6 (debian build), but fails starting with php 7.0.{0,1,2} (all vanilla versions from php.net)

If I repack the archive (unpack and pack it back with tar cvf) it works fine. At first I thought the cause of the problem was that the archive did not include directories, but other similar archive (also without folder entries) http://download.pear.php.net/package/Console_CommandLine-1.2.1.tgz opens just fine.

Test script:
---------------
#!/bin/bash
for ver in 5.3.29 system 7.0.0 7.0.1 7.0.2; do 
  phpenv local $ver
  php -r 'echo phpversion() . "\n"; new \PharData("bad/Structures_Graph-1.1.1.tar");'
done

Expected result:
----------------
5.3.29
5.6.16-4
7.0.0
7.0.1
7.0.2

Actual result:
--------------
5.3.29
5.6.16-4
7.0.0
PHP Fatal error:  Uncaught UnexpectedValueException: phar error: tar-based phar "Structures_Graph-1.1.1/tests/BasicGraphTest.php" cannot be registered in Command line code:1
Stack trace:
#0 Command line code(1): PharData->__construct('bad/Structures_...')
#1 {main}
  thrown in Command line code on line 1
7.0.1
PHP Fatal error:  Uncaught UnexpectedValueException: phar error: tar-based phar "Structures_Graph-1.1.1/tests/BasicGraphTest.php" cannot be registered in Command line code:1
Stack trace:
#0 Command line code(1): PharData->__construct('bad/Structures_...')
#1 {main}
  thrown in Command line code on line 1
7.0.2
PHP Fatal error:  Uncaught UnexpectedValueException: phar error: tar-based phar "Structures_Graph-1.1.1/tests/BasicGraphTest.php" cannot be registered in Command line code:1
Stack trace:
#0 Command line code(1): PharData->__construct('bad/Structures_...')
#1 {main}
  thrown in Command line code on line 1