Normalize Post.fast_count queries

fixes #1008, fixes #2019

app/models/post.rb

@@ -727,7 +727,7 @@ class Post < ActiveRecord::Base
     def get_count_from_cache(tags)
       count = Cache.get(count_cache_key(tags))
 
-      if count.nil?
+      if count.nil? && !CurrentUser.safe_mode? && !CurrentUser.hide_deleted_posts?
         count = select_value_sql("SELECT post_count FROM tags WHERE name = ?", tags.to_s)
       end
 
@@ -747,6 +747,13 @@ class Post < ActiveRecord::Base
     end
 
     def count_cache_key(tags)
+      if CurrentUser.safe_mode?
+        tags = "#{tags} rating:s".strip
+      end
+      if CurrentUser.hide_deleted_posts?
+        tags = "#{tags} -status:deleted".strip
+      end
+
       "pfc:#{Cache.sanitize(tags)}"
     end
 
@@ -774,9 +781,7 @@ class Post < ActiveRecord::Base
 
     def fast_count_search(tags)
       count = Post.with_timeout(500, Danbooru.config.blank_tag_search_fast_count || 1_000_000) do
-        CurrentUser.without_safe_mode do
-          Post.tag_match(tags).count
-        end
+        Post.tag_match(tags).count
       end
       if count > 0
         set_count_in_cache(tags, count)

test/unit/post_test.rb

@@ -1328,6 +1328,56 @@ class PostTest < ActiveSupport::TestCase
         assert_equal(1, Post.fast_count("ccc"))
       end
     end
+
+    context "The cache" do
+      context "when shared between users on danbooru/safebooru" do
+        setup do
+          FactoryGirl.create(:post, :tag_string => "aaa bbb", :rating => "q")
+          FactoryGirl.create(:post, :tag_string => "aaa bbb", :rating => "s")
+          FactoryGirl.create(:post, :tag_string => "aaa bbb", :rating => "s")
+          CurrentUser.stubs(:safe_mode?).returns(true)
+          Post.fast_count("aaa")
+          CurrentUser.stubs(:safe_mode?).returns(false)
+          Post.fast_count("bbb")
+        end
+
+        should "be accurate on danbooru" do
+          CurrentUser.stubs(:safe_mode?).returns(false)
+          assert_equal(3, Post.fast_count("aaa"))
+          assert_equal(3, Post.fast_count("bbb"))
+        end
+
+        should "be accurate on safebooru" do
+          CurrentUser.stubs(:safe_mode?).returns(true)
+          assert_equal(2, Post.fast_count("aaa"))
+          assert_equal(2, Post.fast_count("bbb"))
+        end
+      end
+
+      context "when shared between users with the deleted post filter on/off" do
+        setup do
+          FactoryGirl.create(:post, :tag_string => "aaa bbb", :is_deleted => true)
+          FactoryGirl.create(:post, :tag_string => "aaa bbb", :is_deleted => false)
+          FactoryGirl.create(:post, :tag_string => "aaa bbb", :is_deleted => false)
+          CurrentUser.user.stubs(:hide_deleted_posts?).returns(true)
+          Post.fast_count("aaa")
+          CurrentUser.user.stubs(:hide_deleted_posts?).returns(false)
+          Post.fast_count("bbb")
+        end
+
+        should "be accurate with the deleted post filter on" do
+          CurrentUser.user.stubs(:hide_deleted_posts?).returns(true)
+          assert_equal(2, Post.fast_count("aaa"))
+          assert_equal(2, Post.fast_count("bbb"))
+        end
+
+        should "be accurate with the deleted post filter off" do
+          CurrentUser.user.stubs(:hide_deleted_posts?).returns(false)
+          assert_equal(3, Post.fast_count("aaa"))
+          assert_equal(3, Post.fast_count("bbb"))
+        end
+      end
+    end
   end
 
   context "Reverting: " do