[FIX] mail: properly make urls absolute in escaped attributes

`_replace_local_links` ensures urls are given as absolute rather
relative paths, for link `href`, img `src` and within styles. This
failed when the style contained escaped single quotes (eg:
`background-image: url("/my_url/path");`). This commit adapts the
failing regex appropriately.

X-original-commit: 2af980e8cdc72d35729ef2fbaf5067fe7e72bbb8
Part-of: odoo/odoo#80621

addons/mail/models/mail_render_mixin.py

@@ -162,7 +162,14 @@ class MailRenderMixin(models.AbstractModel):
         _sub_relative2absolute.base_url = base_url
         html = re.sub(r"""(<img(?=\s)[^>]*\ssrc=")(/[^/][^"]+)""", _sub_relative2absolute, html)
         html = re.sub(r"""(<a(?=\s)[^>]*\shref=")(/[^/][^"]+)""", _sub_relative2absolute, html)
-        html = re.sub(r"""(<[^>]+\bstyle="[^"]+\burl\('?)(/[^/'][^'")]+)""", _sub_relative2absolute, html)
+        html = re.sub(re.compile(
+            r"""( # Group 1: element up to url in style
+                <[^>]+\bstyle=" # Element with a style attribute
+                [^"]+\burl\( # Style attribute contains "url(" style
+                (?:&\#34;|')?) # url style may start with (escaped) quote: capture it
+            ( # Group 2: url itself
+                /(?:[^'")]|(?!&\#34;))+ # stop at the first closing quote
+        )""", re.VERBOSE), _sub_relative2absolute, html)
 
         return wrapper(html)
 

addons/mail/tests/test_mail_render.py

@@ -221,7 +221,7 @@ class TestMailRender(common.MailCommon):
         rendered_local_links = [
             '<div style="background-image:url(%s/web/path?a=a&b=b);"/>' % base_url,
             '<div style="background-image:url(\'%s/web/path?a=a&b=b\');"/>' % base_url,
-            '<div style="background-image:url(&#34;/web/path?a=a&b=b&#34;);"/>'
+            '<div style="background-image:url(&#34;%s/web/path?a=a&b=b&#34;);"/>' % base_url
         ]
         for source, expected in zip(local_links_template_bits, rendered_local_links):
             rendered = self.env['mail.render.mixin']._replace_local_links(source)