Fix #3387: Safebooru: Two tag searches fail for members.

Makes the `rating:s` and `-status:deleted` tags not count against the
tag limit.

app/models/tag.rb

@@ -427,7 +427,7 @@ class Tag < ApplicationRecord
       }
 
       scan_query(query).each do |token|
-        q[:tag_count] += 1 unless token == "status:deleted" || token =~ /\Alimit:.+\Z/
+        q[:tag_count] += 1 unless Danbooru.config.is_unlimited_tag?(token)
 
         if token =~ /\A(#{METATAGS}):(.+)\Z/i
           g1 = $1.downcase

config/danbooru_default_config.rb

@@ -169,6 +169,11 @@ module Danbooru
       end
     end
 
+    # Return true if the given tag shouldn't count against the user's tag search limit.
+    def is_unlimited_tag?(tag)
+      !!(tag =~ /\A(-?status:deleted|rating:s.*|limit:.+)\z/i)
+    end
+
     # After this many pages, the paginator will switch to sequential mode.
     def max_numbered_pages
       1_000

test/unit/post_test.rb

@@ -2292,6 +2292,14 @@ class PostTest < ActiveSupport::TestCase
       end
     end
 
+    should "not count free tags against the user's search limit" do
+      post1 = FactoryGirl.create(:post, tag_string: "aaa bbb rating:s")
+
+      Danbooru.config.expects(:is_unlimited_tag?).with("rating:s").once.returns(true)
+      Danbooru.config.expects(:is_unlimited_tag?).with(anything).twice.returns(false)
+      assert_tag_match([post1], "aaa bbb rating:s")
+    end
+
     should "succeed for exclusive tag searches with no other tag" do
       post1 = FactoryGirl.create(:post, :rating => "s", :tag_string => "aaa")
       assert_nothing_raised do
@@ -2425,6 +2433,15 @@ class PostTest < ActiveSupport::TestCase
             assert_equal(1, Post.fast_count(""))
           end
 
+          should "not fail for a two tag search by a member" do
+            post1 = FactoryGirl.create(:post, tag_string: "aaa bbb rating:s")
+            post2 = FactoryGirl.create(:post, tag_string: "aaa bbb rating:e")
+
+            Danbooru.config.expects(:is_unlimited_tag?).with("rating:s").once.returns(true)
+            Danbooru.config.expects(:is_unlimited_tag?).with(anything).twice.returns(false)
+            assert_equal(1, Post.fast_count("aaa bbb"))
+          end
+
           should "set the value in cache" do
             Post.expects(:set_count_in_cache).with("rating:s", kind_of(Integer)).once
             Post.fast_count("")