Merge branch 'master' into adequaterecord

* master: (96 commits)
  clarify CHANGELOG [ci skip].
  Fix Generation of proper migration when   ActiveRecord::Base.pluralize_table_names = false.
  update comments to reflect that options support is not available
  synchronize changelogs and 4.1 release notes. [ci skip]
  do not rely on method_missing hitting arel
  use ARel factory methods for building AST nodes
  Fix date_select option overwriting html classes
  - Rename `increment_or_decrement` to an apt `set_cache_value` since it actually doesn't increment/decrement in localstore.
  Check if any sqlite files are not included in the gitignore
  Remove sqlite3 lines from .gitignore if the application is not using sqlite3.
  Adding active_model in Rails::Info
  Clean up tables after each test.
  Swapped parameters of assert_equal in assert_select
  Update test helper to use latest Digestor API
  Digestor should just rely on the finder to know about the format and the variant -- trying to pass it back in makes a mess of things (oh, and doesnt work)
  Log the full path, including variant, that the digestor is trying to find
  Fix for digestor to consider variants for partials -- this still needs more testing!!
  fix log_tags request object grammar
  Extract with_example_table into helper method.
  test for structure:dump without schema information table. refs eafec46
  ...

Conflicts:
	activerecord/test/cases/relation/where_chain_test.rb

7 files changed, 53 insertions, 61 deletions

diff --git a/activerecord/lib/active_record/connection_adapters/abstract/connection_pool.rb b/activerecord/lib/active_record/connection_adapters/abstract/connection_pool.rb
index fd185de589..db80c0faee 100644
--- a/activerecord/lib/active_record/connection_adapters/abstract/connection_pool.rb
+++ b/activerecord/lib/active_record/connection_adapters/abstract/connection_pool.rb
@@ -58,13 +58,11 @@ module ActiveRecord
     # * +checkout_timeout+: number of seconds to block and wait for a connection
     #   before giving up and raising a timeout error (default 5 seconds).
     # * +reaping_frequency+: frequency in seconds to periodically run the
-    #   Reaper, which attempts to find and close dead connections, which can
-    #   occur if a programmer forgets to close a connection at the end of a
-    #   thread or a thread dies unexpectedly. (Default nil, which means don't
-    #   run the Reaper).
-    # * +dead_connection_timeout+: number of seconds from last checkout
-    #   after which the Reaper will consider a connection reapable. (default
-    #   5 seconds).
+    #   Reaper, which attempts to find and recover connections from dead
+    #   threads, which can occur if a programmer forgets to close a
+    #   connection at the end of a thread or a thread dies unexpectedly.
+    #   Regardless of this setting, the Reaper will be invoked before every
+    #   blocking wait. (Default nil, which means don't schedule the Reaper).
     class ConnectionPool
       # Threadsafe, fair, FIFO queue.  Meant to be used by ConnectionPool
       # with which it shares a Monitor.  But could be a generic Queue.
@@ -222,7 +220,7 @@ module ActiveRecord
 
       include MonitorMixin
 
-      attr_accessor :automatic_reconnect, :checkout_timeout, :dead_connection_timeout
+      attr_accessor :automatic_reconnect, :checkout_timeout
       attr_reader :spec, :connections, :size, :reaper
 
       # Creates a new ConnectionPool object. +spec+ is a ConnectionSpecification
@@ -237,7 +235,6 @@ module ActiveRecord
         @spec = spec
 
         @checkout_timeout = spec.config[:checkout_timeout] || 5
-        @dead_connection_timeout = spec.config[:dead_connection_timeout] || 5
         @reaper  = Reaper.new self, spec.config[:reaping_frequency]
         @reaper.run
 
@@ -361,11 +358,13 @@ module ActiveRecord
       # calling +checkout+ on this pool.
       def checkin(conn)
         synchronize do
+          owner = conn.owner
+
           conn.run_callbacks :checkin do
             conn.expire
           end
 
-          release conn
+          release conn, owner
 
           @available.add conn
         end
@@ -378,22 +377,28 @@ module ActiveRecord
           @connections.delete conn
           @available.delete conn
 
-          # FIXME: we might want to store the key on the connection so that removing
-          # from the reserved hash will be a little easier.
-          release conn
+          release conn, conn.owner
 
           @available.add checkout_new_connection if @available.any_waiting?
         end
       end
 
-      # Removes dead connections from the pool.  A dead connection can occur
-      # if a programmer forgets to close a connection at the end of a thread
+      # Recover lost connections for the pool.  A lost connection can occur if
+      # a programmer forgets to checkin a connection at the end of a thread
       # or a thread dies unexpectedly.
       def reap
-        synchronize do
-          stale = Time.now - @dead_connection_timeout
-          connections.dup.each do |conn|
-            if conn.in_use? && stale > conn.last_use && !conn.active_threadsafe?
+        stale_connections = synchronize do
+          @connections.select do |conn|
+            conn.in_use? && !conn.owner.alive?
+          end
+        end
+
+        stale_connections.each do |conn|
+          synchronize do
+            if conn.active?
+              conn.reset!
+              checkin conn
+            else
               remove conn
             end
           end
@@ -415,20 +420,15 @@ module ActiveRecord
         elsif @connections.size < @size
           checkout_new_connection
         else
+          reap
           @available.poll(@checkout_timeout)
         end
       end
 
-      def release(conn)
-        thread_id = if @reserved_connections[current_connection_id] == conn
-          current_connection_id
-        else
-          @reserved_connections.keys.find { |k|
-            @reserved_connections[k] == conn
-          }
-        end
+      def release(conn, owner)
+        thread_id = owner.object_id
 
-        @reserved_connections.delete thread_id if thread_id
+        @reserved_connections.delete thread_id
       end
 
       def new_connection
diff --git a/activerecord/lib/active_record/connection_adapters/abstract/database_statements.rb b/activerecord/lib/active_record/connection_adapters/abstract/database_statements.rb
index 9371d6f992..deea857a18 100644
--- a/activerecord/lib/active_record/connection_adapters/abstract/database_statements.rb
+++ b/activerecord/lib/active_record/connection_adapters/abstract/database_statements.rb
@@ -26,14 +26,7 @@ module ActiveRecord
 
       # Returns an ActiveRecord::Result instance.
       def select_all(arel, name = nil, binds = [])
-        if arel.is_a?(Relation)
-          relation = arel
-          arel = relation.arel
-          if !binds || binds.empty?
-            binds = relation.bind_values
-          end
-        end
-
+        arel, binds = binds_from_relation arel, binds
         select(to_sql(arel, binds), name, binds)
       end
 
@@ -53,10 +46,7 @@ module ActiveRecord
       # Returns an array of the values of the first column in a select:
       #   select_values("SELECT id FROM companies LIMIT 3") => [1,2,3]
       def select_values(arel, name = nil)
-        binds = []
-        if arel.is_a?(Relation)
-          arel, binds = arel.arel, arel.bind_values
-        end
+        arel, binds = binds_from_relation arel, []
         select_rows(to_sql(arel, binds), name, binds).map(&:first)
       end
 
@@ -395,6 +385,13 @@ module ActiveRecord
           row = result.rows.first
           row && row.first
         end
+
+        def binds_from_relation(relation, binds)
+          if relation.is_a?(Relation) && binds.blank?
+            relation, binds = relation.arel, relation.bind_values
+          end
+          [relation, binds]
+        end
     end
   end
 end
diff --git a/activerecord/lib/active_record/connection_adapters/abstract/query_cache.rb b/activerecord/lib/active_record/connection_adapters/abstract/query_cache.rb
index adc23a6674..4a4506c7f5 100644
--- a/activerecord/lib/active_record/connection_adapters/abstract/query_cache.rb
+++ b/activerecord/lib/active_record/connection_adapters/abstract/query_cache.rb
@@ -63,6 +63,7 @@ module ActiveRecord
 
       def select_all(arel, name = nil, binds = [])
         if @query_cache_enabled && !locked?(arel)
+          arel, binds = binds_from_relation arel, binds
           sql = to_sql(arel, binds)
           cache_sql(sql, binds) { super(sql, name, binds) }
         else
diff --git a/activerecord/lib/active_record/connection_adapters/abstract_adapter.rb b/activerecord/lib/active_record/connection_adapters/abstract_adapter.rb
index 4828e45f62..2d45079168 100644
--- a/activerecord/lib/active_record/connection_adapters/abstract_adapter.rb
+++ b/activerecord/lib/active_record/connection_adapters/abstract_adapter.rb
@@ -71,8 +71,8 @@ module ActiveRecord
       define_callbacks :checkout, :checkin
 
       attr_accessor :visitor, :pool
-      attr_reader :schema_cache, :last_use, :in_use, :logger
-      alias :in_use? :in_use
+      attr_reader :schema_cache, :owner, :logger
+      alias :in_use? :owner
 
       def self.type_cast_config_to_integer(config)
         if config =~ SIMPLE_INT
@@ -96,9 +96,8 @@ module ActiveRecord
         super()
 
         @connection          = connection
-        @in_use              = false
+        @owner               = nil
         @instrumenter        = ActiveSupport::Notifications.instrumenter
-        @last_use            = false
         @logger              = logger
         @pool                = pool
         @schema_cache        = SchemaCache.new self
@@ -120,9 +119,8 @@ module ActiveRecord
 
       def lease
         synchronize do
-          unless in_use
-            @in_use   = true
-            @last_use = Time.now
+          unless in_use?
+            @owner = Thread.current
           end
         end
       end
@@ -133,7 +131,7 @@ module ActiveRecord
       end
 
       def expire
-        @in_use = false
+        @owner = nil
       end
 
       def unprepared_visitor
@@ -268,12 +266,6 @@ module ActiveRecord
       def active?
       end
 
-      # Adapter should redefine this if it needs a threadsafe way to approximate
-      # if the connection is active
-      def active_threadsafe?
-        active?
-      end
-
       # Disconnects from the database if already connected, and establishes a
       # new connection with the database. Implementors should call super if they
       # override the default implementation.
diff --git a/activerecord/lib/active_record/connection_adapters/connection_specification.rb b/activerecord/lib/active_record/connection_adapters/connection_specification.rb
index 3f8b14bf67..9a133168f8 100644
--- a/activerecord/lib/active_record/connection_adapters/connection_specification.rb
+++ b/activerecord/lib/active_record/connection_adapters/connection_specification.rb
@@ -237,8 +237,8 @@ module ActiveRecord
         # hash and merges with the rest of the hash.
         # Connection details inside of the "url" key win any merge conflicts
         def resolve_hash_connection(spec)
-          if url = spec.delete("url")
-            connection_hash = resolve_string_connection(url)
+          if spec["url"] && spec["url"] !~ /^jdbc:/
+            connection_hash = resolve_string_connection(spec.delete("url"))
             spec.merge!(connection_hash)
           end
           spec
diff --git a/activerecord/lib/active_record/connection_adapters/postgresql/schema_statements.rb b/activerecord/lib/active_record/connection_adapters/postgresql/schema_statements.rb
index ae8ede4b42..e0afa989cd 100644
--- a/activerecord/lib/active_record/connection_adapters/postgresql/schema_statements.rb
+++ b/activerecord/lib/active_record/connection_adapters/postgresql/schema_statements.rb
@@ -327,6 +327,7 @@ module ActiveRecord
               AND attr.attrelid     = cons.conrelid
               AND attr.attnum       = cons.conkey[1]
               AND cons.contype      = 'p'
+              AND dep.classid       = 'pg_class'::regclass
               AND dep.refobjid      = '#{quote_table_name(table)}'::regclass
           end_sql
 
diff --git a/activerecord/lib/active_record/connection_adapters/postgresql_adapter.rb b/activerecord/lib/active_record/connection_adapters/postgresql_adapter.rb
index e5f7913c70..bcad9f30d7 100644
--- a/activerecord/lib/active_record/connection_adapters/postgresql_adapter.rb
+++ b/activerecord/lib/active_record/connection_adapters/postgresql_adapter.rb
@@ -603,10 +603,6 @@ module ActiveRecord
         false
       end
 
-      def active_threadsafe?
-        @connection.connect_poll != PG::PGRES_POLLING_FAILED
-      end
-
       # Close then reopen the connection.
       def reconnect!
         super
@@ -616,7 +612,12 @@ module ActiveRecord
 
       def reset!
         clear_cache!
-        super
+        reset_transaction
+        unless @connection.transaction_status == ::PG::PQTRANS_IDLE
+          @connection.query 'ROLLBACK'
+        end
+        @connection.query 'DISCARD ALL'
+        configure_connection
       end
 
       # Disconnects from the database if already connected. Otherwise, this