Fixed line detection.

app/models/transaction/signature_detection.rb

@@ -52,10 +52,11 @@ class Transaction::SignatureDetection
     return if !user
     return if !user.preferences
     return if !user.preferences[:signature_detection]
-    article.preferences[:signature_detection] = SignatureDetection.find_signature_line_by_article(
+    line = SignatureDetection.find_signature_line_by_article(
       user,
       article
     )
+    article.preferences[:signature_detection] = line
     article.save
   end
 

lib/signature_detection.rb

@@ -157,7 +157,7 @@ returns
 
 =end
 
-  def find_signature_line_by_article(user, article)
+  def self.find_signature_line_by_article(user, article)
     return if !user.preferences[:signature_detection]
     SignatureDetection.find_signature_line(
       user.preferences[:signature_detection],