11 files changed, 73 insertions, 8 deletions
diff --git a/activerecord/CHANGELOG.md b/activerecord/CHANGELOG.md
index 71a740f300..252639ef69 100644
--- a/activerecord/CHANGELOG.md
+++ b/activerecord/CHANGELOG.md
@@ -9,6 +9,23 @@
 
    *Yves Senn*
 
+*   Use `nil?` instead of `blank?` to check whether dynamic finder with a bang
+    should raise RecordNotFound.
+    Fixes #7238.
+
+    *Nikita Afanasenko*
+
+*   Fix deleting from a HABTM join table upon destroying an object of a model
+    with optimistic locking enabled.
+    Fixes #5332.
+
+    *Nick Rogers*
+
+*   Use query cache/uncache when using ENV["DATABASE_URL"].
+    Fixes #6951. [Backport #8074]
+
+    *kennyj*
+
 *   Do not create useless database transaction when building `has_one` association. [Backport #8154]
 
     Example:
diff --git a/activerecord/lib/active_record/locking/optimistic.rb b/activerecord/lib/active_record/locking/optimistic.rb
index 7deac2588a..b2881991d5 100644
--- a/activerecord/lib/active_record/locking/optimistic.rb
+++ b/activerecord/lib/active_record/locking/optimistic.rb
@@ -102,6 +102,8 @@ module ActiveRecord
         def destroy #:nodoc:
           return super unless locking_enabled?
 
+          destroy_associations
+
           if persisted?
             table = self.class.arel_table
             lock_col = self.class.locking_column
diff --git a/activerecord/lib/active_record/query_cache.rb b/activerecord/lib/active_record/query_cache.rb
index 466d148901..2156889a0f 100644
--- a/activerecord/lib/active_record/query_cache.rb
+++ b/activerecord/lib/active_record/query_cache.rb
@@ -6,19 +6,19 @@ module ActiveRecord
     module ClassMethods
       # Enable the query cache within the block if Active Record is configured.
       def cache(&block)
-        if ActiveRecord::Base.configurations.blank?
-          yield
-        else
+        if ActiveRecord::Base.connected?
           connection.cache(&block)
+        else
+          yield
         end
       end
 
       # Disable the query cache within the block if Active Record is configured.
       def uncached(&block)
-        if ActiveRecord::Base.configurations.blank?
-          yield
-        else
+        if ActiveRecord::Base.connected?
           connection.uncached(&block)
+        else
+          yield
         end
       end
     end
diff --git a/activerecord/lib/active_record/relation/finder_methods.rb b/activerecord/lib/active_record/relation/finder_methods.rb
index abc67d9c15..44aeb309d6 100644
--- a/activerecord/lib/active_record/relation/finder_methods.rb
+++ b/activerecord/lib/active_record/relation/finder_methods.rb
@@ -263,7 +263,7 @@ module ActiveRecord
       conditions = Hash[attributes.map {|a| [a, args[attributes.index(a)]]}]
       result = where(conditions).send(match.finder)
 
-      if match.bang? && result.blank?
+      if match.bang? && result.nil?
         raise RecordNotFound, "Couldn't find #{@klass.name} with #{conditions.to_a.collect {|p| p.join(' = ')}.join(', ')}"
       else
         yield(result) if block_given?
diff --git a/activerecord/test/cases/finder_test.rb b/activerecord/test/cases/finder_test.rb
index 5d72e35c60..e50a334958 100644
--- a/activerecord/test/cases/finder_test.rb
+++ b/activerecord/test/cases/finder_test.rb
@@ -652,6 +652,11 @@ class FinderTest < ActiveRecord::TestCase
     assert_raise(ActiveRecord::RecordNotFound) { Topic.find_by_title!("The First Topic!") }
   end
 
+  def test_find_by_one_attribute_bang_with_blank_defined
+    blank_topic = BlankTopic.create(:title => "The Blank One")
+    assert_equal blank_topic, BlankTopic.find_by_title!("The Blank One")
+  end
+
   def test_find_by_one_attribute_with_order_option
     assert_equal accounts(:signals37), Account.find_by_credit_limit(50, :order => 'id')
     assert_equal accounts(:rails_core_account), Account.find_by_credit_limit(50, :order => 'id DESC')
diff --git a/activerecord/test/cases/locking_test.rb b/activerecord/test/cases/locking_test.rb
index 015a3ccefd..c74986eb69 100644
--- a/activerecord/test/cases/locking_test.rb
+++ b/activerecord/test/cases/locking_test.rb
@@ -20,7 +20,7 @@ class ReadonlyNameShip < Ship
 end
 
 class OptimisticLockingTest < ActiveRecord::TestCase
-  fixtures :people, :legacy_things, :references, :string_key_objects
+  fixtures :people, :legacy_things, :references, :string_key_objects, :peoples_treasures
 
   def test_non_integer_lock_existing
     s1 = StringKeyObject.find("record1")
@@ -267,6 +267,16 @@ class SetLockingColumnTest < ActiveRecord::TestCase
       assert_equal "omg", k.original_locking_column
     end
   end
+  
+  def test_removing_has_and_belongs_to_many_associations_upon_destroy
+    p = RichPerson.create!
+    p.treasures.create!
+    assert !p.treasures.empty?
+    p.destroy
+    assert p.treasures.empty?
+    assert RichPerson.connection.select_all("SELECT * FROM peoples_treasures WHERE rich_person_id = 1").empty?
+  end
+  
 end
 
 class OptimisticLockingWithSchemaChangeTest < ActiveRecord::TestCase
diff --git a/activerecord/test/cases/query_cache_test.rb b/activerecord/test/cases/query_cache_test.rb
index dd881f8230..dfc6ea2457 100644
--- a/activerecord/test/cases/query_cache_test.rb
+++ b/activerecord/test/cases/query_cache_test.rb
@@ -173,6 +173,17 @@ class QueryCacheTest < ActiveRecord::TestCase
       assert_queries(2) { task.lock!; task.lock! }
     end
   end
+
+  def test_cache_is_available_when_connection_is_connected
+    conf = ActiveRecord::Base.configurations
+
+    ActiveRecord::Base.configurations = {}
+    Task.cache do
+      assert_queries(1) { Task.find(1); Task.find(1) }
+    end
+  ensure
+    ActiveRecord::Base.configurations = conf
+  end
 end
 
 class QueryCacheExpiryTest < ActiveRecord::TestCase
diff --git a/activerecord/test/fixtures/peoples_treasures.yml b/activerecord/test/fixtures/peoples_treasures.yml
new file mode 100644
index 0000000000..a72b190d0c
--- /dev/null
+++ b/activerecord/test/fixtures/peoples_treasures.yml
@@ -0,0 +1,3 @@
+michael_diamond:
+  rich_person_id: <%= ActiveRecord::Fixtures.identify(:michael) %>
+  treasure_id: <%= ActiveRecord::Fixtures.identify(:diamond) %>
diff --git a/activerecord/test/models/person.rb b/activerecord/test/models/person.rb
index 5b92227f4a..5991aed55b 100644
--- a/activerecord/test/models/person.rb
+++ b/activerecord/test/models/person.rb
@@ -86,3 +86,9 @@ class TightPerson < ActiveRecord::Base
 end
 
 class TightDescendant < TightPerson; end
+
+class RichPerson < ActiveRecord::Base
+  self.table_name = 'people'
+  
+  has_and_belongs_to_many :treasures, :join_table => 'peoples_treasures'
+end
diff --git a/activerecord/test/models/topic.rb b/activerecord/test/models/topic.rb
index 1a1a18166a..5166fefe81 100644
--- a/activerecord/test/models/topic.rb
+++ b/activerecord/test/models/topic.rb
@@ -112,6 +112,12 @@ class ImportantTopic < Topic
   serialize :important, Hash
 end
 
+class BlankTopic < Topic
+  def blank?
+    true
+  end
+end
+
 module Web
   class Topic < ActiveRecord::Base
     has_many :replies, :dependent => :destroy, :foreign_key => "parent_id", :class_name => 'Web::Reply'
diff --git a/activerecord/test/schema/schema.rb b/activerecord/test/schema/schema.rb
index 8a3dfbb35a..67a20a610c 100644
--- a/activerecord/test/schema/schema.rb
+++ b/activerecord/test/schema/schema.rb
@@ -480,6 +480,11 @@ ActiveRecord::Schema.define do
     t.references :best_friend_of
     t.timestamps
   end
+  
+  create_table :peoples_treasures, :id => false, :force => true do |t|
+    t.column :rich_person_id, :integer
+    t.column :treasure_id, :integer
+  end
 
   create_table :pets, :primary_key => :pet_id ,:force => true do |t|
     t.string :name