FIX: reset edit_reason in posts when creating a new version.

spec/components/post_revisor_spec.rb

@@ -208,6 +208,19 @@ describe PostRevisor do
         expect(post.revisions.count).to eq(1)
       end
 
+      it "resets the edit_reason attribute in post model" do
+        SiteSetting.editing_grace_period = 5
+        post = Fabricate(:post, raw: 'hello world')
+        revisor = PostRevisor.new(post)
+        revisor.revise!(post.user, { raw: 'hello world123456789', edit_reason: 'this is my reason' }, revised_at: post.updated_at + 1.second)
+        post.reload
+        expect(post.edit_reason).to eq('this is my reason')
+
+        revisor.revise!(post.user, { raw: 'hello world4321' }, revised_at: post.updated_at + 6.second)
+        post.reload
+        expect(post.edit_reason).not_to be_present
+      end
+
       it "does not create a new version if an edit reason is provided and its the same as the current edit reason" do
         post = Fabricate(:post, raw: 'hello world', edit_reason: 'this is my reason')
         revisor = PostRevisor.new(post)