Posts by trust level 3 users do not have nofollow on their external links.

app/models/post.rb

@@ -133,7 +133,16 @@ class Post < ActiveRecord::Base
     return raw if cook_method == Post.cook_methods[:raw_html]
 
     # Default is to cook posts
-    Plugin::Filter.apply(:after_post_cook, self, post_analyzer.cook(*args))
+    cooked = if !self.user || !self.user.has_trust_level?(:leader)
+      post_analyzer.cook(*args)
+    else
+      # At trust level 3, we don't apply nofollow to links
+      cloned = args.dup
+      cloned[1] ||= {}
+      cloned[1][:omit_nofollow] = true
+      post_analyzer.cook(*cloned)
+    end
+    Plugin::Filter.apply( :after_post_cook, self, cooked )
   end
 
   # Sometimes the post is being edited by someone else, for example, a mod.

app/models/user.rb

@@ -408,6 +408,7 @@ class User < ActiveRecord::Base
   def change_trust_level!(level)
     raise "Invalid trust level #{level}" unless TrustLevel.valid_level?(level)
     self.trust_level = TrustLevel.levels[level]
+    self.bio_raw_will_change! # So it can get re-cooked based on the new trust level
     transaction do
       self.save!
       Group.user_trust_level_change!(self.id, self.trust_level)
@@ -526,7 +527,7 @@ class User < ActiveRecord::Base
 
   def cook
     if bio_raw.present?
-      self.bio_cooked = PrettyText.cook(bio_raw) if bio_raw_changed?
+      self.bio_cooked = PrettyText.cook(bio_raw, omit_nofollow: self.has_trust_level?(:leader)) if bio_raw_changed?
     else
       self.bio_cooked = nil
     end

lib/pretty_text.rb

@@ -167,7 +167,7 @@ module PrettyText
     # we have a minor inconsistency
     cloned[:topicId] = opts[:topic_id]
     sanitized = markdown(text.dup, cloned)
-    sanitized = add_rel_nofollow_to_user_content(sanitized) if SiteSetting.add_rel_nofollow_to_user_content
+    sanitized = add_rel_nofollow_to_user_content(sanitized) if !cloned[:omit_nofollow] && SiteSetting.add_rel_nofollow_to_user_content
     sanitized
   end
 

spec/components/pretty_text_spec.rb

@@ -74,6 +74,10 @@ describe PrettyText do
     it "should not inject nofollow for bar.foo.com" do
       (PrettyText.cook("<a href='http://bar.foo.com/test.html'>cnn</a>") !~ /nofollow/).should be_true
     end
+
+    it "should not inject nofollow if omit_nofollow option is given" do
+      (PrettyText.cook('<a href="http://cnn.com">cnn</a>', omit_nofollow: true) !~ /nofollow/).should be_true
+    end
   end
 
   describe "Excerpt" do

spec/models/post_spec.rb

@@ -771,4 +771,20 @@ describe Post do
     end
   end
 
+  describe "cooking" do
+    let(:post) { Fabricate.build(:post, post_args.merge(raw: "please read my blog http://blog.example.com")) }
+
+    it "should add nofollow to links in the post for trust levels below 3" do
+      post.user.trust_level = 2
+      post.save
+      post.cooked.should =~ /nofollow/
+    end
+
+    it "should not add nofollow for trust level 3 and higher" do
+      post.user.trust_level = 3
+      post.save
+      (post.cooked =~ /nofollow/).should be_false
+    end
+  end
+
 end

spec/models/user_spec.rb

@@ -762,21 +762,40 @@ describe User do
     context "with a user that has a link in their bio" do
       let(:user) { Fabricate.build(:user, bio_raw: "im sissy and i love http://ponycorns.com") }
 
-      before do
+      it "includes the link as nofollow if the user is not new" do
-        # Let's cook that bio up good
         user.send(:cook)
-      end
-
-      it "includes the link if the user is not new" do
         expect(user.bio_excerpt).to eq("im sissy and i love <a href='http://ponycorns.com' rel='nofollow'>http://ponycorns.com</a>")
         expect(user.bio_processed).to eq("<p>im sissy and i love <a href=\"http://ponycorns.com\" rel=\"nofollow\">http://ponycorns.com</a></p>")
       end
 
       it "removes the link if the user is new" do
         user.trust_level = TrustLevel.levels[:newuser]
+        user.send(:cook)
         expect(user.bio_excerpt).to eq("im sissy and i love http://ponycorns.com")
         expect(user.bio_processed).to eq("<p>im sissy and i love http://ponycorns.com</p>")
       end
+
+      it "includes the link without nofollow if the user is trust level 3 or higher" do
+        user.trust_level = TrustLevel.levels[:leader]
+        user.send(:cook)
+        expect(user.bio_excerpt).to eq("im sissy and i love <a href='http://ponycorns.com'>http://ponycorns.com</a>")
+        expect(user.bio_processed).to eq("<p>im sissy and i love <a href=\"http://ponycorns.com\">http://ponycorns.com</a></p>")
+      end
+
+      it "removes nofollow from links in bio when trust level is increased" do
+        user.save
+        user.change_trust_level!(:leader)
+        expect(user.bio_excerpt).to eq("im sissy and i love <a href='http://ponycorns.com'>http://ponycorns.com</a>")
+        expect(user.bio_processed).to eq("<p>im sissy and i love <a href=\"http://ponycorns.com\">http://ponycorns.com</a></p>")
+      end
+
+      it "adds nofollow to links in bio when trust level is decreased" do
+        user.trust_level = TrustLevel.levels[:leader]
+        user.save
+        user.change_trust_level!(:regular)
+        expect(user.bio_excerpt).to eq("im sissy and i love <a href='http://ponycorns.com' rel='nofollow'>http://ponycorns.com</a>")
+        expect(user.bio_processed).to eq("<p>im sissy and i love <a href=\"http://ponycorns.com\" rel=\"nofollow\">http://ponycorns.com</a></p>")
+      end
     end
 
   end