Regression for paginatable array

Sometimes, we want to make an array just paginatable without changing
its elements. Make it so if total count is explicitly given and it is
greater than the length of the given array. #516

lib/kaminari/models/array_extension.rb

@@ -17,11 +17,15 @@ module Kaminari
         extend Kaminari::PageScopeMethods
       end
 
-      if @_total_count
-        original_array = original_array.first(@_total_count)
+      if @_total_count.present? && @_total_count <= original_array.count
+        original_array = original_array.first(@_total_count)[@_offset_value, @_limit_value]
       end
 
-      super(original_array[@_offset_value, @_limit_value] || [])
+      if @_total_count.nil?
+        original_array = original_array[@_offset_value, @_limit_value]
+      end
+
+      super(original_array || [])
     end
 
     def entry_name

spec/models/array_spec.rb

@@ -142,27 +142,30 @@ describe Kaminari::PaginatableArray do
   end
 
   context 'when setting total count explicitly' do
-    context "total_count > size of the given array" do
+    context "array 1..10, page 5, per 10, total_count 9999" do
       subject { Kaminari::PaginatableArray.new((1..10).to_a, :total_count => 9999).page(5).per(10) }
 
-      it { should have(0).items }
-      its(:first) { should be_nil }
+      it { should have(10).items }
+      its(:first) { should == 1 }
+      its(:current_page) { should == 5 }
       its(:total_count) { should == 9999 }
     end
 
-    context "total_count == size of the given array" do
+    context "array 1..15, page 1, per 10, total_count 15" do
       subject { Kaminari.paginate_array((1..15).to_a, :total_count => 15).page(1).per(10) }
 
       it { should have(10).items }
       its(:first) { should == 1 }
+      its(:current_page) { should == 1 }
       its(:total_count) { should == 15 }
     end
 
-    context "total_count < size of the given array" do
+    context "array 1..25, page 2, per 10, total_count 15" do
       subject { Kaminari.paginate_array((1..25).to_a, :total_count => 15).page(2).per(10) }
 
       it { should have(5).items }
       its(:first) { should == 11 }
+      its(:current_page) { should == 2 }
       its(:total_count) { should == 15 }
     end
   end