If min entropy setting is greater than min post/body length setting, then use a sensible min entropy value instead

lib/text_sentinel.rb

@@ -5,6 +5,8 @@ class TextSentinel
 
   attr_accessor :text
 
+  ENTROPY_SCALE = 0.7
+
   def initialize(text, opts=nil)
     @opts = opts || {}
     @text = text.to_s.encode('UTF-8', invalid: :replace, undef: :replace, replace: '')
@@ -15,14 +17,20 @@ class TextSentinel
     if opts[:private_message]
       scale_entropy = SiteSetting.min_private_message_post_length.to_f / SiteSetting.min_post_length.to_f
       entropy = (entropy * scale_entropy).to_i
+      entropy = (SiteSetting.min_private_message_post_length.to_f * ENTROPY_SCALE).to_i if entropy > SiteSetting.min_private_message_post_length
+    else
+      entropy = (SiteSetting.min_post_length.to_f * ENTROPY_SCALE).to_i if entropy > SiteSetting.min_post_length
     end
     TextSentinel.new(text, min_entropy: entropy)
   end
 
   def self.title_sentinel(text)
-    TextSentinel.new(text,
-                     min_entropy: SiteSetting.title_min_entropy,
-                     max_word_length: SiteSetting.max_word_length)
+    entropy = if SiteSetting.min_topic_title_length > SiteSetting.title_min_entropy
+      SiteSetting.title_min_entropy
+    else
+      (SiteSetting.min_topic_title_length.to_f * ENTROPY_SCALE).to_i
+    end
+    TextSentinel.new(text, min_entropy: entropy, max_word_length: SiteSetting.max_word_length)
   end
 
   # Entropy is a number of how many unique characters the string needs.

spec/components/text_sentinel_spec.rb

@@ -90,7 +90,7 @@ describe TextSentinel do
       TextSentinel.new("jfewjfoejwfojeojfoejofjeo3" * 5, max_word_length: 30).should_not be_valid
     end
 
-    it "doesn't except junk symbols as a string" do
+    it "doesn't accept junk symbols as a string" do
       TextSentinel.new("[[[").should_not be_valid
       TextSentinel.new("<<<").should_not be_valid
       TextSentinel.new("{{$!").should_not be_valid
@@ -98,4 +98,30 @@ describe TextSentinel do
 
   end
 
+  context 'title_sentinel' do
+
+    it "uses a sensible min entropy value when min title length is less than title_min_entropy" do
+      SiteSetting.stubs(:min_topic_title_length).returns(3)
+      SiteSetting.stubs(:title_min_entropy).returns(10)
+      TextSentinel.title_sentinel('Hey').should be_valid
+    end
+
+  end
+
+  context 'body_sentinel' do
+
+    it "uses a sensible min entropy value when min body length is less than min entropy" do
+      SiteSetting.stubs(:min_post_length).returns(3)
+      SiteSetting.stubs(:body_min_entropy).returns(7)
+      TextSentinel.body_sentinel('Yup').should be_valid
+    end
+
+    it "uses a sensible min entropy value when min pm body length is less than min entropy" do
+      SiteSetting.stubs(:min_post_length).returns(5)
+      SiteSetting.stubs(:min_private_message_post_length).returns(3)
+      SiteSetting.stubs(:body_min_entropy).returns(7)
+      TextSentinel.body_sentinel('Lol', private_message: true).should be_valid
+    end
+  end
+
 end