Re: [PATCH 4/4 v8] config: write to $XDG_CONFIG_HOME/git/config file if appropriate

We can squash this into PATCH 1:

--- a/Documentation/git-config.txt
+++ b/Documentation/git-config.txt

@@ -209,7 +209,9 @@ $XDG_CONFIG_HOME/git/config::
        Second user-specific configuration file. If $XDG_CONFIG_HOME is not set
        or empty, $HOME/.config/git/config will be used. Any single-valued
        variable set in this file will be overwritten by whatever is in
-       ~/.gitconfig.
+       ~/.gitconfig. Support for this file was added after Git
+       1.7.11, so if you sometimes use older versions of Git, it's a
+       good idea not to create this file.