MySQL: SET SQL_AUTO_IS_NULL=0 so 'where id is null' doesn't select the last inserted id. Closes #6778.

git-svn-id: http://svn-commit.rubyonrails.org/rails/trunk@6064 5ecf4fe2-1ee6-0310-87b1-e25e094e27de

3 files changed, 12 insertions, 0 deletions

diff --git a/activerecord/CHANGELOG b/activerecord/CHANGELOG
index cda2262ed4..85b5262994 100644
--- a/activerecord/CHANGELOG
+++ b/activerecord/CHANGELOG
@@ -1,5 +1,7 @@
 *SVN*
 
+* MySQL: SET SQL_AUTO_IS_NULL=0 so 'where id is null' doesn't select the last inserted id.  #6778 [Jonathan Viney, timc]
+
 * Use Date#to_s(:db) for quoted dates.  #7411 [Michael Schoen]
 
 * Don't create instance writer methods for class attributes.  Closes #7401 [Rick]
diff --git a/activerecord/lib/active_record/connection_adapters/mysql_adapter.rb b/activerecord/lib/active_record/connection_adapters/mysql_adapter.rb
index 08b3c22ec7..842258f1ea 100755
--- a/activerecord/lib/active_record/connection_adapters/mysql_adapter.rb
+++ b/activerecord/lib/active_record/connection_adapters/mysql_adapter.rb
@@ -388,6 +388,10 @@ module ActiveRecord
           @connection.ssl_set(@config[:sslkey], @config[:sslcert], @config[:sslca], @config[:sslcapath], @config[:sslcipher]) if @config[:sslkey]
           @connection.real_connect(*@connection_options)
           execute("SET NAMES '#{encoding}'") if encoding
+
+          # By default, MySQL 'where id is null' selects the last inserted id.
+          # Turn this off. http://dev.rubyonrails.org/ticket/6778
+          execute("SET SQL_AUTO_IS_NULL=0")
         end
 
         def select(sql, name = nil)
diff --git a/activerecord/test/finder_test.rb b/activerecord/test/finder_test.rb
index 1e6e4cf6cd..eb1e4d639c 100644
--- a/activerecord/test/finder_test.rb
+++ b/activerecord/test/finder_test.rb
@@ -460,6 +460,12 @@ class FinderTest < Test::Unit::TestCase
     end
   end
 
+  # http://dev.rubyonrails.org/ticket/6778
+  def test_find_ignores_previously_inserted_record
+    post = Post.create!
+    assert_equal [], Post.find_all_by_id(nil)
+  end
+
   def test_find_by_empty_ids
     assert_equal [], Post.find([])
   end