allow pre+code tags in rendered HTML

mediagoblin/static/css/base.css

@@ -544,18 +544,34 @@ table.media_panel th {
   margin-left: 10px;
 }
 
-/* ASCII art */
+/* ASCII art and code */
 
 @font-face {
   font-family: Inconsolata;
   src: local('Inconsolata'), url('../fonts/Inconsolata.otf') format('opentype')
 }
 
-.ascii-wrapper pre {
+pre, code {
   font-family: Inconsolata, monospace;
   line-height: 1em;
 }
 
+pre {
+  overflow: auto;
+  /* -10px, because it is usually preceded by <p> with margin-bottom: 20px */ 
+  margin: -10px 0 10px 0;
+}
+
+.comment_wrapper pre {
+  /* same as above, but with 2px */
+  margin: 8px 0 10px 0;
+}
+
+.ascii-wrapper pre {
+  /* but it should not affect the ASCII art */
+  margin: 0;
+}
+
 /* Media queries and other responsivisivity */
 @media screen and (max-width: 940px) {
   .media_pane {

mediagoblin/tools/text.py

@@ -36,7 +36,8 @@ HTML_CLEANER = Cleaner(
     forms=True,
     annoying_tags=True,
     allow_tags=[
-        'div', 'b', 'i', 'em', 'strong', 'p', 'ul', 'ol', 'li', 'a', 'br'],
+        'div', 'b', 'i', 'em', 'strong', 'p', 'ul', 'ol', 'li', 'a', 'br',
+        'pre', 'code'],
     remove_unknown_tags=False, # can't be used with allow_tags
     safe_attrs_only=True,
     add_nofollow=True, # for now