Merge branch '2.7' into 2.8

components/http_foundation.rst

@@ -288,6 +288,7 @@ represents an HTTP message. But when moving from a legacy system, adding
 methods or changing some default behavior might help. In that case, register a
 PHP callable that is able to create an instance of your ``Request`` class::
 
+    use AppBundle\Http\SpecialRequest;
     use Symfony\Component\HttpFoundation\Request;
 
     Request::setFactory(function (

components/process.rst

@@ -124,6 +124,26 @@ are done doing other stuff::
     which means that your code will halt at this line until the external
     process is completed.
 
+.. note::
+
+    If a ``Response`` is sent **before** a child process had a chance to complete,
+    the server process will be killed (depending on your OS). It means that
+    your task will be stopped right away. Running an asynchronous process
+    is not the same as running a process that survives its parent process.
+
+    If you want your process to survive the request/response cycle, you can
+    take advantage of the ``kernel.terminate`` event, and run your command
+    **synchronously** inside this event. Be aware that ``kernel.terminate``
+    is called only if you use PHP-FPM.
+
+.. caution::
+
+    Beware also that if you do that, the said PHP-FPM process will not be
+    available to serve any new request until the subprocess is finished. This
+    means you can quickly block your FPM pool if you're not careful enough.
+    That is why it's generally way better not to do any fancy things even
+    after the request is sent, but to use a job queue instead.
+
 :method:`Symfony\\Component\\Process\\Process::wait` takes one optional argument:
 a callback that is called repeatedly whilst the process is still running, passing
 in the output and its type::

reference/dic_tags.rst

@@ -353,6 +353,11 @@ wrapping their names with ``%`` characters).
     sense most of the times to prevent accessing those services directly instead
     of using the generic service alias.
 
+.. note::
+
+    You need to manually add the ``Symfony\Component\DependencyInjection\Compiler\AutoAliasServicePass``
+    compiler pass to the container for this feature to work.
+
 console.command
 ---------------