From 9082ddf455942639f02f43f7870a3f4cac347edf Mon Sep 17 00:00:00 2001
From: Albert Yi <albert@carbonfive.com>
Date: Thu, 26 Jul 2018 15:28:34 -0700
Subject: [PATCH] potential fix for #3783

---
 app/models/post.rb     |  2 +-
 test/unit/post_test.rb | 19 +++++++++++++++++++
 2 files changed, 20 insertions(+), 1 deletion(-)

diff --git a/app/models/post.rb b/app/models/post.rb
index 90ee52c6f..acbcdac99 100644
--- a/app/models/post.rb
+++ b/app/models/post.rb
@@ -542,7 +542,7 @@ class Post < ApplicationRecord
     end
 
     def tag_array_was
-      @tag_array_was ||= Tag.scan_tags(tag_string_before_last_save || tag_string_was)
+      @tag_array_was ||= Tag.scan_tags(tag_string_in_database.presence || tag_string_before_last_save || "")
     end
 
     def tags
diff --git a/test/unit/post_test.rb b/test/unit/post_test.rb
index 2269498e0..57c70d6f9 100644
--- a/test/unit/post_test.rb
+++ b/test/unit/post_test.rb
@@ -1603,6 +1603,16 @@ class PostTest < ActiveSupport::TestCase
   end
 
   context "Updating:" do
+    context "an existing post" do
+      setup { @post = FactoryBot.create(:post) }
+
+      should "call Tag.increment_post_counts with the correct params" do
+        @post.reload
+        Tag.expects(:increment_post_counts).once.with(["abc"])
+        @post.update(tag_string: "tag1 abc")
+      end
+    end
+
     context "A rating unlocked post" do
       setup { @post = FactoryBot.create(:post) }
       subject { @post }
@@ -1823,6 +1833,15 @@ class PostTest < ActiveSupport::TestCase
         assert_equal(user2.name, post.uploader_name)
       end
 
+      context "tag post counts" do
+        setup { @post = FactoryBot.build(:post) }
+
+        should "call Tag.increment_post_counts with the correct params" do
+          Tag.expects(:increment_post_counts).once.with(["tag1", "tag2"])
+          @post.save
+        end
+      end
+
       should "increment the uploaders post_upload_count" do
         assert_difference(-> { CurrentUser.user.post_upload_count }) do
           post = FactoryBot.create(:post, uploader: CurrentUser.user)