From 2f681254ee9481f30baa53720c1570decb437725 Mon Sep 17 00:00:00 2001
From: Francesco Rodriguez <lrodriguezsanc@gmail.com>
Date: Mon, 30 Apr 2012 10:49:20 -0500
Subject: [PATCH] delete_all raise an error if a limit is provided - fixes
 #4979

---
 activerecord/lib/active_record/relation.rb | 2 ++
 activerecord/test/cases/relations_test.rb  | 4 ++++
 2 files changed, 6 insertions(+)

diff --git a/activerecord/lib/active_record/relation.rb b/activerecord/lib/active_record/relation.rb
index 333d31d8a37d9..779e052e3c4f7 100644
--- a/activerecord/lib/active_record/relation.rb
+++ b/activerecord/lib/active_record/relation.rb
@@ -390,6 +390,8 @@ def destroy(id)
     # If you need to destroy dependent associations or call your <tt>before_*</tt> or
     # +after_destroy+ callbacks, use the +destroy_all+ method instead.
     def delete_all(conditions = nil)
+      raise ActiveRecordError.new("delete_all doesn't support limit scope") if self.limit_value
+
       if conditions
         where(conditions).delete_all
       else
diff --git a/activerecord/test/cases/relations_test.rb b/activerecord/test/cases/relations_test.rb
index 4b8b57bac2880..3ef357e29747a 100644
--- a/activerecord/test/cases/relations_test.rb
+++ b/activerecord/test/cases/relations_test.rb
@@ -688,6 +688,10 @@ def test_delete_all_loaded
     assert davids.loaded?
   end
 
+  def test_delete_all_limit_error
+    assert_raises(ActiveRecord::ActiveRecordError) { Author.limit(10).delete_all }
+  end
+
   def test_select_argument_error
     assert_raises(ArgumentError) { Developer.select }
   end