add specs for post ownership change without revision

spec/models/post_spec.rb

@@ -874,6 +874,27 @@ describe Post do
     end
   end
 
+  describe "#set_owner" do
+    let(:post) { Fabricate(:post) }
+    let(:coding_horror) { Fabricate(:coding_horror) }
+
+    it "will change owner of a post correctly" do
+      post.set_owner(coding_horror, Discourse.system_user)
+      post.reload
+
+      expect(post.user).to eq(coding_horror)
+      expect(post.revisions.size).to eq(1)
+    end
+
+    it "skips creating new post revision if skip_revision is true" do
+      post.set_owner(coding_horror, Discourse.system_user, true)
+      post.reload
+
+      expect(post.user).to eq(coding_horror)
+      expect(post.revisions.size).to eq(0)
+    end
+  end
+
   describe ".rebake_old" do
     it "will catch posts it needs to rebake" do
       post = create_post