with_exclusive_scope does not work properly if ARel is passed. It doe…

…s work nicely if hash is passed. Blow up if user is attempting it pass ARel to with_exclusive_scope.

[#3838 state:resolved]

Signed-off-by: José Valim <jose.valim@gmail.com>

activerecord/lib/active_record/base.rb

@@ -1156,7 +1156,20 @@ def with_scope(method_scoping = {}, action = :merge, &block)
         end
 
         # Works like with_scope, but discards any nested properties.
+        # TODO : this method should be deprecated in favor of standard query API
         def with_exclusive_scope(method_scoping = {}, &block)
+          if method_scoping.values.any? { |e| e.is_a?(ActiveRecord::Relation) }
+            msg =<<-MSG
+              ARel can not be used with_exclusive_scope. You can either specify hash style conditions to with_exclusive_scope like this:
+              User.with_exclusive_scope {:find => :conditions => {:active => true} } do
+              end
+
+              Or you can use unscoped method instead of with_exclusive_scope like this:
+              User.unscoped.where(:active => true) do
+              end
+            MSG
+            raise ArgumentError.new(msg)
+          end
           with_scope(method_scoping, :overwrite, &block)
         end
 

activerecord/test/cases/method_scoping_test.rb

@@ -283,6 +283,12 @@ def test_replace_options
     end
   end
 
+  def test_with_exclusive_scope_with_relation
+    assert_raise(ArgumentError) do
+      Developer.all_johns
+    end
+  end
+
   def test_append_conditions
     Developer.send(:with_scope, :find => { :conditions => "name = 'David'" }) do
       Developer.send(:with_scope, :find => { :conditions => 'salary = 80000' }) do

activerecord/test/models/developer.rb

@@ -55,6 +55,12 @@ def find_least_recent
   def log=(message)
     audit_logs.build :message => message
   end
+
+  def self.all_johns 
+    self.with_exclusive_scope :find => where(:name => 'John') do
+      self.all
+    end
+  end
 end
 
 class AuditLog < ActiveRecord::Base
@@ -103,4 +109,4 @@ class DeveloperCalledJamis < ActiveRecord::Base
 class PoorDeveloperCalledJamis < ActiveRecord::Base
   self.table_name = 'developers'
   default_scope :conditions => { :name => 'Jamis', :salary => 50000 }
-end
+end