decide per index to reconcile class name field

lib/thinking_sphinx/configuration/minimum_fields.rb

@@ -6,8 +6,6 @@ def initialize(indices)
   end
 
   def reconcile
-    return unless no_inheritance_columns?
-
     field_collections.each do |collection|
       collection.fields.delete_if do |field|
         field.name == 'sphinx_internal_class_name'
@@ -20,18 +18,19 @@ def reconcile
   attr_reader :indices
 
   def field_collections
-    indices_of_type('plain').collect(&:sources).flatten +
+    plain_indices_without_inheritance.collect(&:sources).flatten +
     indices_of_type('rt')
   end
 
   def indices_of_type(type)
     indices.select { |index| index.type == type }
   end
 
-  def no_inheritance_columns?
-    indices.select { |index|
-      index.model.table_exists? &&
-      index.model.column_names.include?(index.model.inheritance_column)
-    }.empty?
+  def inheritance_columns?(index)
+    index.model.table_exists? && index.model.column_names.include?(index.model.inheritance_column)
+  end
+
+  def plain_indices_without_inheritance
+    indices_of_type('plain').reject(&method(:inheritance_columns?))
   end
 end

spec/thinking_sphinx/configuration/minimum_fields_spec.rb

@@ -38,13 +38,13 @@
     expect(index_b.fields).to eq([field_b2])
   end
 
-  it 'keeps the class name fields when one index model has a type column' do
+  it 'removes the class name fields only for the indices without type column' do
     allow(model_a).to receive(:column_names).and_return(['id', 'name', 'type'])
     allow(model_b).to receive(:column_names).and_return(['id', 'name'])
 
     subject.reconcile
 
     expect(index_a.sources.first.fields).to eq([field_a1, field_a2])
-    expect(index_b.fields).to eq([field_b1, field_b2])
+    expect(index_b.fields).to eq([field_b2])
   end
 end