work around opcache phar issues

opcache is using the parameter passed to mapPhar as a cache key, thus if
multiple different versions of sacy are to be used with the same
instance of opcache, only the files inside of the first phar file loaded
will be seen.

This patch produces a unique alias based of the content of the files to
be included, thus allowing multiple versions of sacy to coexist

build.php

@@ -59,8 +59,9 @@
 $outfile = 'block.asset_compile.php';
 $outdir = isset($args['o']) ? $args['o'] : implode(DIRECTORY_SEPARATOR, array(__DIR__, 'build'));
 $target = implode(DIRECTORY_SEPARATOR, array($outdir, 'temp.phar'));
+if (file_exists($target)) unlink($target);
 
-$arch = new Phar($target, 0, 'sacy.phar');
+$arch = new ContentHashedPhar($target, 0, 'sacy.phar');
 $arch->startBuffering();
 $arch->buildFromIterator(new SacySupportFilesFilter(
             new RecursiveIteratorIterator(new RecursiveDirectoryIterator($srcdir), RecursiveIteratorIterator::SELF_FIRST),
@@ -106,17 +107,19 @@
 
 $arch->stopBuffering();
 
+$opcache_bug_workaround_name = sha1($arch->getContentHash().file_get_contents(__FILE__));
+
 if ($comp != Phar::NONE)
     $arch->compressFiles($comp);
 
-$stub ='<?php Phar::interceptFileFuncs();
-    define("____SACY_BUNDLED", 1);
-    Phar::mapPhar("sacy.phar");
-    include("phar://sacy.phar/sacy/ext-translators.php");
-    include("phar://sacy.phar/sacy/fragment-cache.php");
-    include("phar://sacy.phar/sacy/phpsass.php");
-    include("phar://sacy.phar/sacy/sacy.php");
-    '.
+$stub ="<?php Phar::interceptFileFuncs();
+    define('____SACY_BUNDLED', 1);
+    Phar::mapPhar('$opcache_bug_workaround_name.phar');
+    include('phar://$opcache_bug_workaround_name.phar/sacy/ext-translators.php');
+    include('phar://$opcache_bug_workaround_name.phar/sacy/fragment-cache.php');
+    include('phar://$opcache_bug_workaround_name.phar/sacy/phpsass.php');
+    include('phar://$opcache_bug_workaround_name.phar/sacy/sacy.php');
+    ".
     de_phptag(file_get_contents($srcdir.DIRECTORY_SEPARATOR.'block.asset_compile.php')).
     "\n__HALT_COMPILER();";
 $arch->setStub($stub);
@@ -130,6 +133,40 @@ function de_phptag($str){
 
 }
 
+class ContentHashedPhar extends Phar {
+    private $hash;
+
+    function __construct($fname, $flags){
+        parent::__construct($fname, $flags);
+        $this->hash = null;
+    }
+
+    function buildFromIterator(Iterator $it, $base_dir=null){
+        foreach($it as $f){
+            $this->addFileToHash($f);
+        }
+        parent::buildFromIterator($it, $base_dir);
+    }
+
+    function offsetSet($k, $v){
+        $this->addFileToHash($v);
+        parent::offsetSet($k, $v);
+    }
+
+    function getContentHash(){
+        return $this->hash;
+    }
+
+    function addFile($file, $localname=null){
+        $this->addFile($file);
+        parent::addFile($file, $localname);
+    }
+
+    private function addFileToHash($f){
+        $this->hash = sha1($this->hash . file_get_contents($f));
+    }
+}
+
 class SacySkipSubdirsFilter extends RecursiveFilterIterator{
     private $skipdirs;