Issue #2265977 by olli: fixed php backend serialization.

core/lib/Drupal/Core/Cache/PhpBackend.php

@@ -254,23 +254,8 @@ public function removeBin() {
    *   The cache item to store.
    */
   protected function writeItem($cid, \stdClass $item) {
-    $data = str_replace('\\', '\\\\', serialize($item));
-
-    // Data can contain 'EOF' or 'EOF;', either of which cause a fatal PHP
-    // error when the cache item is read back from disk. To guard against this,
-    // dynamically generate a heredoc EOF string that is not contained in $data.
-    $suffix = '';
-    do {
-      $EOF = 'EOF' . $suffix;
-    } while ($suffix++ < 1000 && ($unsafe_eof_in_data = preg_match('/^' . $EOF . ';?$/m', $data)));
-
-    if (!$unsafe_eof_in_data) {
-      $content = "<?php return unserialize(<<<$EOF
-$data
-$EOF
-);";
-      $this->storage()->save($cid, $content);
-    }
+    $content = '<?php return unserialize(' . var_export(serialize($item), TRUE) . ');';
+    $this->storage()->save($cid, $content);
   }
 
   /**

core/modules/system/lib/Drupal/system/Tests/Cache/GenericCacheBackendUnitTestBase.php

@@ -181,6 +181,12 @@ public function testSetGet() {
     $this->assertTrue($cached->valid, 'Item is marked as valid.');
     $this->assertEqual($cached->created, REQUEST_TIME, 'Created time is correct.');
     $this->assertEqual($cached->expire, Cache::PERMANENT, 'Expire time is correct.');
+
+    $with_variable = array('foo' => '$bar');
+    $backend->set('test6', $with_variable);
+    $cached = $backend->get('test6');
+    $this->assert(is_object($cached), "Backend returned an object for cache id test6.");
+    $this->assertIdentical($with_variable, $cached->data);
   }
 
   /**