wiki: Assume force if previous value is None.

This allows clients that don't send the previous IDs to skip conflict detection and update the wikified text fields.
This allows for backwards compatibility, as well as making stylesheet updating not require an extra lookup.

r2/r2/controllers/api.py

@@ -1227,7 +1227,12 @@ def POST_subreddit_stylesheet(self, form, jquery,
                                   stylesheet_contents = '', prevstyle='', op='save'):
 
         report, parsed = c.site.parse_css(stylesheet_contents)
-
+
+        # Use the raw POST value as we need to tell the difference between
+        # None/Undefined and an empty string.  The validators use a default
+        # value with both of those cases and would need to be changed. 
+        # In order to avoid breaking functionality, this was done instead.
+        prevstyle = request.post.get('prevstyle')
         if not report:
             return self.abort(403,'forbidden')
 
@@ -1502,17 +1507,20 @@ def apply_wikid_field(sr, form, pagename, value, prev, field, error):
         redir = False
         kw = dict((k, v) for k, v in kw.iteritems()
                   if k in ('name', 'title', 'domain', 'description',
-                           'prev_description_id', 'prev_public_description_id',
                            'show_media', 'show_cname_sidebar', 'type', 'link_type', 'lang',
                            'css_on_cname', 'header_title', 'over_18',
                            'wikimode', 'wiki_edit_karma', 'wiki_edit_age',
                            'allow_top', 'public_description'))
-
-        description = kw.pop('description')
-        prev_desc = kw.pop('prev_description_id')
-
+
         public_description = kw.pop('public_description')
-        prev_pubdesc = kw.pop('prev_public_description_id')
+        description = kw.pop('description')
+
+        # Use the raw POST value as we need to tell the difference between
+        # None/Undefined and an empty string.  The validators use a default
+        # value with both of those cases and would need to be changed. 
+        # In order to avoid breaking functionality, this was done instead.
+        prev_desc = request.post.get('prev_description_id')
+        prev_pubdesc = request.post.get('prev_public_description_id')
 
         def update_wiki_text(sr):
             apply_wikid_field(sr,

r2/r2/controllers/wiki.py

@@ -235,7 +235,11 @@ class WikiApiController(WikiController):
               content=VMarkdown(('content')))
     def POST_wiki_edit(self, pageandprevious, content):
         page, previous = pageandprevious
-        previous = previous._id if previous else None
+        # Use the raw POST value as we need to tell the difference between
+        # None/Undefined and an empty string.  The validators use a default
+        # value with both of those cases and would need to be changed. 
+        # In order to avoid breaking functionality, this was done instead.
+        previous = previous._id if previous else request.post.get('previous')
         try:
             if page.name == 'config/stylesheet':
                 report, parsed = c.site.parse_css(content, verify=False)

r2/r2/models/wiki.py

@@ -272,6 +272,7 @@ def has_editor(self, editor):
     def revise(self, content, previous = None, author=None, force=False, reason=None):
         if self.content == content:
             return
+        force = True if previous is None else force
         max_length = special_length_restrictions_bytes.get(self.name, MAX_PAGE_LENGTH_BYTES)
         if len(content) > max_length:
             raise ContentLengthError(max_length)