Update patches page

contributing/code/patches.rst

@@ -93,6 +93,29 @@ Set up your user information with your real name and a working email address:
     If you are new to Git, we highly recommend you to read the excellent and
     free `ProGit`_ book.
 
+.. tip::
+
+    Windows users: when installing Git, the installer will ask what to do with
+    line endings and suggests to replace all Lf by CRLF. This is the wrong
+    setting if you wish to contribute to Symfony! Selecting the as-is method is
+    your best choice, as git will convert your line feeds to the ones in the
+    repository. If you have already installed Git, you can check the value of
+    this setting by typing:
+
+    .. code-block:: bash
+
+        $ git config core.autocrlf
+
+    This will return either "false", "input" or "true", "true" and "false" being
+    the wrong values. Set it to another value by typing:
+
+    .. code-block:: bash
+
+        $ git config --global core.autocrlf input
+
+    Replace --global by --local if you want to set it only for the active
+    repository
+
 Get the Symfony2 source code:
 
 * Create a `GitHub`_ account and sign in;
@@ -132,6 +155,11 @@ Create the topic branch with the following command:
 
     $ git checkout -b BRANCH_NAME master
 
+.. tip::
+
+    Replace "master" by, for example, 2.0, if you wish to submit a patch to the
+    2.0 branch.
+
 .. tip::
 
     Use a descriptive name for your branch (`ticket_XXX` where `XXX` is the
@@ -215,6 +243,35 @@ with master, don't merge; and force the push to the origin:
     $ git rebase -f upstream/master
     $ git push -f origin BRANCH_NAME
 
+.. note::
+
+    when doing a push -f (or --force), always specify the branch name explicitly
+    to avoid messing other branches in the repo (--force tells git that you
+    really want to mess with things so do it carefully).
+
+Often, moderators will ask you to "squash" your commits. This means you will
+convert many commits to one commit. To do this, use the rebase command:
+
+.. code-block:: bash
+
+    $ git rebase -i head~3
+    $ git push -f origin BRANCH_NAME
+
+The number 3 here must equal the amount of commits in your branch. After you
+type this command, an editor will popup showing a list of commits:
+
+.. code-block:: text
+
+    pick 1a31be6 first commit
+    pick 7fc64b4 second commit
+    pick 7d33018 third commit
+
+To squash all commits into the first one, remove the word "pick" before the
+second and the last commits, and replace it by the word "squash" or just "s".
+When you save, git will start rebasing, and if succesful, will ask you to edit
+the commit message, which by default is a listing of the commit messages of all
+the commits. When you finish, execute the push command.
+
 .. note::
 
     All patches you are going to submit must be released under the MIT