Merge branch '3.4' into 4.4

* 3.4:
  [HttpFoundation] workaround PHP bug in the session module

Author: nicolas-grekas

Session/Storage/Handler/AbstractSessionHandler.php

@@ -71,6 +71,15 @@ public function validateId($sessionId)
         $this->prefetchData = $this->read($sessionId);
         $this->prefetchId = $sessionId;
 
+        if (\PHP_VERSION_ID < 70317 || (70400 <= \PHP_VERSION_ID && \PHP_VERSION_ID < 70405)) {
+            // work around https://bugs.php.net/79413
+            foreach (debug_backtrace(DEBUG_BACKTRACE_IGNORE_ARGS) as $frame) {
+                if (!isset($frame['class']) && isset($frame['function']) && \in_array($frame['function'], ['session_regenerate_id', 'session_create_id'], true)) {
+                    return '' === $this->prefetchData;
+                }
+            }
+        }
+
         return '' !== $this->prefetchData;
     }
 

Tests/Session/Storage/Handler/Fixtures/regenerate.expected

@@ -11,6 +11,7 @@ validateId
 read
 doRead: abc|i:123;
 read
+doRead: abc|i:123;
 
 write
 doWrite: abc|i:123;