[MERGE] forward port of branch saas-9 up to 89873cb

1 files changed, 9 insertions, 1 deletions

diff --git a/doc/reference/guidelines.rst b/doc/reference/guidelines.rst
index e4cfe1255ec..54a00097705 100644
--- a/doc/reference/guidelines.rst
+++ b/doc/reference/guidelines.rst
@@ -11,6 +11,14 @@ aim to improve the quality of the code (better readability of source,
 ...) and  Odoo Apps. Indeed, proper code ought ease maintenance, aid
 debugging, lower complexity and promote reliability.
 
+.. warning::
+
+    These guidelines are written with new modules and new files in mind. When
+    modifying existing files, the original style of the file strictly supersedes
+    any other style guidelines. In other words, never modify existing files in
+    order to apply these guidelines, to avoid disrupting the revision history of
+    each line. For more details, see our `pull request guide <https://odoo.com/submit-pr>`_.
+
 Module structure
 ================
 
@@ -271,7 +279,7 @@ Idioms
 - Always favor *Readability* over *conciseness* or using the language features or idioms.
 - Use list comprehension, dict comprehension, and basic manipulation using ``map``, ``filter``, ``sum``, ... They make the code easier to read.
 - The same applies for recordset methods : use ``filtered``, ``mapped``, ``sorted``, ...
-- Each python file should have ``# -*- coding: utf-8 -*-`` as first line
+- Each python file should have ``# coding: utf-8 `` as first line
 - Use the ``UserError`` defined in ``openerp.exceptions`` instead of overriding ``Warning``, or find a more appropriate exception in *exceptions.py*
 - Document your code (docstring on methods, simple comments for the tricky part of the code)
 - Use meaningful variable/class/method names