Merge branch '2.8'

* 2.8:
  add subject variable to expression context
  [Process] Fix signaling/stopping logic on Windows
  Forward compatibility with AbstractLayout* 2.8 tests
  [Yaml] minor CS cleaning
  [Console] do not encode backslashes in console default description

Process.php

@@ -775,36 +775,24 @@ public function getStatus()
      * Stops the process.
      *
      * @param int|float $timeout The timeout in seconds
-     * @param int       $signal  A POSIX signal to send in case the process has not stop at timeout, default is SIGKILL
+     * @param int       $signal  A POSIX signal to send in case the process has not stop at timeout, default is SIGKILL (9)
      *
      * @return int The exit-code of the process
-     *
-     * @throws RuntimeException if the process got signaled
      */
     public function stop($timeout = 10, $signal = null)
     {
         $timeoutMicro = microtime(true) + $timeout;
         if ($this->isRunning()) {
-            if ('\\' === DIRECTORY_SEPARATOR && !$this->isSigchildEnabled()) {
-                exec(sprintf('taskkill /F /T /PID %d 2>&1', $this->getPid()), $output, $exitCode);
-                if ($exitCode > 0) {
-                    throw new RuntimeException('Unable to kill the process');
-                }
-            }
             // given `SIGTERM` may not be defined and that `proc_terminate` uses the constant value and not the constant itself, we use the same here
             $this->doSignal(15, false);
             do {
                 usleep(1000);
             } while ($this->isRunning() && microtime(true) < $timeoutMicro);
 
             if ($this->isRunning() && !$this->isSigchildEnabled()) {
-                if (null !== $signal || defined('SIGKILL')) {
-                    // avoid exception here :
-                    // process is supposed to be running, but it might have stop
-                    // just after this line.
-                    // in any case, let's silently discard the error, we can not do anything
-                    $this->doSignal($signal ?: SIGKILL, false);
-                }
+                // Avoid exception here: process is supposed to be running, but it might have stopped just
+                // after this line. In any case, let's silently discard the error, we cannot do anything.
+                $this->doSignal($signal ?: 9, false);
             }
         }
 
@@ -1434,7 +1422,18 @@ private function doSignal($signal, $throwException)
             return false;
         }
 
-        if (true !== @proc_terminate($this->process, $signal)) {
+        if ('\\' === DIRECTORY_SEPARATOR) {
+            exec(sprintf('taskkill /F /T /PID %d 2>&1', $this->getPid()), $output, $exitCode);
+            if ($exitCode) {
+                if ($throwException) {
+                    throw new RuntimeException(sprintf('Unable to kill the process (%s).', implode(' ', $output)));
+                }
+
+                return false;
+            }
+        }
+
+        if (true !== @proc_terminate($this->process, $signal) && '\\' !== DIRECTORY_SEPARATOR) {
             if ($throwException) {
                 throw new RuntimeException(sprintf('Error while sending signal `%s`.', $signal));
             }