Allow users to embed Gravatars in messages

We'll use this internally for the commit bot.  We might eventually disable it
for external users.

(imported from commit 3136cd9faadc6b81355889d2ee6472985da87fbe)

zephyr/lib/bugdown.py

@@ -1,6 +1,18 @@
 import re
 import markdown
 
+from zephyr.lib.avatar import gravatar_hash
+
+class Gravatar(markdown.inlinepatterns.Pattern):
+    def handleMatch(self, match):
+        # NB: the first match of our regex is match.group(2) due to
+        # markdown internal matches
+        img = markdown.util.etree.Element('img')
+        img.set('class', 'message_body_gravatar img-rounded')
+        img.set('src', 'https://secure.gravatar.com/avatar/%s?d=identicon&s=30'
+            % (gravatar_hash(match.group(2)),))
+        return img
+
 class Bugdown(markdown.Extension):
     def extendMarkdown(self, md, md_globals):
         del md.inlinePatterns['image_link']
@@ -8,6 +20,8 @@ class Bugdown(markdown.Extension):
         del md.parser.blockprocessors['hashheader']
         del md.parser.blockprocessors['setextheader']
 
+        md.inlinePatterns.add('gravatar', Gravatar(r'!gravatar\(([^)]*)\)'), '_begin')
+
 # We need to re-initialize the markdown engine every 30 messages
 # due to some sort of performance leak in the markdown library.
 MAX_MD_ENGINE_USES = 30

zephyr/static/styles/zephyr.css

@@ -415,3 +415,7 @@ table.floating_recipient {
     margin-top: 0px;
     margin-bottom: 0px;
 }
+
+.message_body_gravatar {
+    margin-bottom: 2px;
+}