A trivial typo (so patch instead of pull request)

[congma]

From e47c876f1aecf475b43a942521ed9b3ce9be3dc6 Mon Sep 17 00:00:00 2001
From: Cong Ma <cong.ma@obspm.fr>
Date: Fri, 4 Nov 2016 13:31:21 +0800
Subject: [PATCH] Fix typo (Py_DECREF) in canonical_function.rst.

---
 doc/sphinx/source/canonical_function.rst | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/doc/sphinx/source/canonical_function.rst b/doc/sphinx/source/canonical_function.rst
index c7762b3..0ea064a 100644
--- a/doc/sphinx/source/canonical_function.rst
+++ b/doc/sphinx/source/canonical_function.rst
@@ -71,7 +71,7 @@ If you are willing to accept NULL arguments then this pattern would be more suit
         Py_INCREF(arg_1);
     }
     
-Of course the same test must be used when calling ``Py_DECFREF``, or just use ``Py_XDECREF``.
+Of course the same test must be used when calling ``Py_DECREF``, or just use ``Py_XDECREF``.
 
 Now we create any local objects, if they are "Borrowed" references we need to incref them. With any abnormal behaviour we do a local jump straight to the cleanup code.
 
-- 
2.10.2

[adamchainz]

You can just edit files on Github and make a PR, which is even easier than a patch file https://help.github.com/articles/editing-files-in-another-user-s-repository/