Created 'upgrade' cookbook section

cookbook/index.rst

@@ -28,7 +28,7 @@ The Cookbook
     symfony1
     templating/index
     testing/index
-    upgrading
+    upgrade/index
     validation/index
     web_server/index
     web_services/index

cookbook/map.rst.inc

@@ -201,9 +201,10 @@
   * (email) :doc:`/cookbook/email/testing`
   * (form) :doc:`/cookbook/form/unit_testing`
 
-* **Upgrading**
+* :doc:`/cookbook/upgrading/index`
 
-  * :doc:`/cookbook/upgrading`
+  * :doc:`/cookbook/upgrading/patch_version`
+  * :doc:`/cookbook/upgrading/minor_version`
 
 * :doc:`/cookbook/validation/index`
 

cookbook/upgrade/_update_all_packages.rst.inc

@@ -0,0 +1,16 @@
+You may also want to upgrade the rest of your libraries. If you've done a
+good job with your `version constraints`_ in ``composer.json``, you can do
+this safely by running:
+
+.. code-block:: bash
+
+    $ composer update
+
+.. caution::
+
+    Beware, if you have some bad `version constraints`_ in your
+    ``composer.json`` (e.g. ``dev-master``), this could upgrade some
+    non-Symfony libraries to new versions that contain backwards-compatibility
+    breaking changes.
+
+.. _`versino constraints`: https://getcomposer.org/doc/01-basic-usage.md#package-versions

cookbook/upgrade/index.rst

@@ -0,0 +1,17 @@
+.. index::
+    single: Upgrading
+
+Upgrading
+=========
+
+So a new Symfony release has come out and you want to upgrade, great! Fortunately,
+because Symfony protects backwards-compatibility very closely, this *should*
+be quite easy.
+
+There are three types of upgrades, all needing a little different preparation:
+
+.. toctree::
+    :maxdepth: 2
+
+    /cookbook/upgrade/patch_version
+    /cookbook/upgrade/minor_version

cookbook/upgrade/minor_version.rst

@@ -0,0 +1,63 @@
+.. index::
+    single: Upgrading; Minor Version
+
+Upgrading a Minor Version (e.g. 2.5.3 to 2.6.1)
+===============================================
+
+If you're upgrading a minor version (where the middle number changes), then
+you should *not* encounter significant backwards compatibility changes. For
+details, see the :doc:`Symfony backwards compatibility promise </contributing/code/bc>`.
+
+However, some backwards-compatibility breaks *are* possible and you'll learn in
+a second how to prepare for them.
+
+There are two steps to upgrading a minor version:
+
+#. :ref:`Update the Symfony library via Composer <upgrade-minor-symfony-composer>`;
+#. :ref:`Update your code to work with the new version <upgrade-minor-symfony-code>`.
+
+.. _`upgrade-minor-symfony-composer`:
+
+1) Update the Symfony Library via Composer
+------------------------------------------
+
+First, you need to update Symfony by modifying your ``composer.json`` file
+to use the new version:
+
+.. code-block:: json
+
+    {
+        "...": "...",
+
+        "require": {
+            "symfony/symfony": "2.6.*",
+        },
+        "...": "...",
+    }
+
+Next, use Composer to download new versions of the libraries:
+
+.. code-block:: bash
+
+    $ composer update symfony/symfony
+
+.. include:: /cookbook/upgrade/_update_all_packages.rst.inc
+
+.. _`upgrade-minor-symfony-code`:
+
+2) Updating Your Code to Work with the new Version
+--------------------------------------------------
+
+In theory, you should be done! However, you *may* need to make a few changes
+to your code to get everything working. Additionally, some features you're
+using might still work, but might now be deprecated. While that's just fine,
+if you know about these deprecations, you can start to fix them over time.
+
+Every version of Symfony comes with an UPGRADE file included in the Symfony
+directory that describes these changes. If you follow the instructions in the
+document and update your code accordingly, it should be save to update in the
+future.
+
+These documents can also be found in the `Symfony Repository`_.
+
+.. _`Symfony Repository`: https://github.com/symfony/symfony

cookbook/upgrade/patch_version.rst

@@ -0,0 +1,26 @@
+.. index::
+    single: Upgrading; Patch Version
+
+Upgrading a Patch Version (e.g. 2.6.0 to 2.6.1)
+===============================================
+
+When a new patch version is released (only the last number changed), it is a
+release that only contains bug fixes. This means that upgrading to a new patch
+version is *really* easy:
+
+.. code-block:: bash
+
+    $ composer update symfony/symfony
+
+That's it! You should not encounter any backwards-compatibility breaks or
+need to change anything else in your code. That's because when you started
+your project, your ``composer.json`` included Symfony using a constraint
+like ``2.6.*``, where only the *last* version number will change when you
+update.
+
+.. tip::
+
+    It is recommended to update to a new patch version as soon as possible, as
+    important bugs and security leaks may be fixed in these new releases.
+
+.. include:: /cookbook/upgrade/_update_all_packages.rst.inc

redirection_map

@@ -23,3 +23,4 @@
 /cookbook/console/generating_urls /cookbook/console/sending_emails
 /components/yaml /components/yaml/introduction
 /components/templating /components/templating/introduction
+/cookbook/upgrading /cookbook/upgrade/index