Merge branch 'master' into add_database_exist_method

11 files changed, 133 insertions, 16 deletions

diff --git a/activerecord/lib/active_record/connection_adapters/abstract/quoting.rb b/activerecord/lib/active_record/connection_adapters/abstract/quoting.rb
index 1b6ba8ce97..93273f6cf6 100644
--- a/activerecord/lib/active_record/connection_adapters/abstract/quoting.rb
+++ b/activerecord/lib/active_record/connection_adapters/abstract/quoting.rb
@@ -114,16 +114,16 @@ module ActiveRecord
       # if the value is a Time responding to usec.
       def quoted_date(value)
         if value.acts_like?(:time)
-          zone_conversion_method = ActiveRecord::Base.default_timezone == :utc ? :getutc : :getlocal
-
-          if value.respond_to?(zone_conversion_method)
-            value = value.send(zone_conversion_method)
+          if ActiveRecord::Base.default_timezone == :utc
+            value = value.getutc if value.respond_to?(:getutc) && !value.utc?
+          else
+            value = value.getlocal if value.respond_to?(:getlocal)
           end
         end
 
         result = value.to_s(:db)
         if value.respond_to?(:usec) && value.usec > 0
-          "#{result}.#{sprintf("%06d", value.usec)}"
+          result << "." << sprintf("%06d", value.usec)
         else
           result
         end
diff --git a/activerecord/lib/active_record/connection_adapters/abstract_mysql_adapter.rb b/activerecord/lib/active_record/connection_adapters/abstract_mysql_adapter.rb
index 70292e6d63..e9ae8d159e 100644
--- a/activerecord/lib/active_record/connection_adapters/abstract_mysql_adapter.rb
+++ b/activerecord/lib/active_record/connection_adapters/abstract_mysql_adapter.rb
@@ -737,7 +737,7 @@ module ActiveRecord
           end.compact.join(", ")
 
           # ...and send them all in one query
-          execute "SET #{encoding} #{sql_mode_assignment} #{variable_assignments}"
+          execute("SET #{encoding} #{sql_mode_assignment} #{variable_assignments}", "SCHEMA")
         end
 
         def column_definitions(table_name) # :nodoc:
diff --git a/activerecord/lib/active_record/connection_adapters/column.rb b/activerecord/lib/active_record/connection_adapters/column.rb
index 279d0b9e84..2708d2756b 100644
--- a/activerecord/lib/active_record/connection_adapters/column.rb
+++ b/activerecord/lib/active_record/connection_adapters/column.rb
@@ -5,6 +5,8 @@ module ActiveRecord
   module ConnectionAdapters
     # An abstract definition of a column in a table.
     class Column
+      include Deduplicable
+
       attr_reader :name, :default, :sql_type_metadata, :null, :default_function, :collation, :comment
 
       delegate :precision, :scale, :limit, :type, :sql_type, to: :sql_type_metadata, allow_nil: true
@@ -76,6 +78,7 @@ module ActiveRecord
       def hash
         Column.hash ^
           name.hash ^
+          name.encoding.hash ^
           default.hash ^
           sql_type_metadata.hash ^
           null.hash ^
@@ -83,6 +86,17 @@ module ActiveRecord
           collation.hash ^
           comment.hash
       end
+
+      private
+        def deduplicated
+          @name = -name
+          @sql_type_metadata = sql_type_metadata.deduplicate if sql_type_metadata
+          @default = -default if default
+          @default_function = -default_function if default_function
+          @collation = -collation if collation
+          @comment = -comment if comment
+          super
+        end
     end
 
     class NullColumn < Column
diff --git a/activerecord/lib/active_record/connection_adapters/deduplicable.rb b/activerecord/lib/active_record/connection_adapters/deduplicable.rb
new file mode 100644
index 0000000000..fb2fd60bbc
--- /dev/null
+++ b/activerecord/lib/active_record/connection_adapters/deduplicable.rb
@@ -0,0 +1,29 @@
+# frozen_string_literal: true
+
+module ActiveRecord
+  module ConnectionAdapters # :nodoc:
+    module Deduplicable
+      extend ActiveSupport::Concern
+
+      module ClassMethods
+        def registry
+          @registry ||= {}
+        end
+
+        def new(*)
+          super.deduplicate
+        end
+      end
+
+      def deduplicate
+        self.class.registry[self] ||= deduplicated
+      end
+      alias :-@ :deduplicate
+
+      private
+        def deduplicated
+          freeze
+        end
+    end
+  end
+end
diff --git a/activerecord/lib/active_record/connection_adapters/mysql/schema_dumper.rb b/activerecord/lib/active_record/connection_adapters/mysql/schema_dumper.rb
index 234fb25fdf..bcd300f3db 100644
--- a/activerecord/lib/active_record/connection_adapters/mysql/schema_dumper.rb
+++ b/activerecord/lib/active_record/connection_adapters/mysql/schema_dumper.rb
@@ -41,13 +41,15 @@ module ActiveRecord
             case column.sql_type
             when /\Atimestamp\b/
               :timestamp
+            when /\A(?:enum|set)\b/
+              column.sql_type
             else
               super
             end
           end
 
           def schema_limit(column)
-            super unless /\A(?:tiny|medium|long)?(?:text|blob)/.match?(column.sql_type)
+            super unless /\A(?:enum|set|(?:tiny|medium|long)?(?:text|blob))\b/.match?(column.sql_type)
           end
 
           def schema_precision(column)
diff --git a/activerecord/lib/active_record/connection_adapters/mysql/type_metadata.rb b/activerecord/lib/active_record/connection_adapters/mysql/type_metadata.rb
index 9167593064..a7232fa249 100644
--- a/activerecord/lib/active_record/connection_adapters/mysql/type_metadata.rb
+++ b/activerecord/lib/active_record/connection_adapters/mysql/type_metadata.rb
@@ -6,9 +6,11 @@ module ActiveRecord
       class TypeMetadata < DelegateClass(SqlTypeMetadata) # :nodoc:
         undef to_yaml if method_defined?(:to_yaml)
 
+        include Deduplicable
+
         attr_reader :extra
 
-        def initialize(type_metadata, extra: "")
+        def initialize(type_metadata, extra: nil)
           super(type_metadata)
           @extra = extra
         end
@@ -25,6 +27,13 @@ module ActiveRecord
             __getobj__.hash ^
             extra.hash
         end
+
+        private
+          def deduplicated
+            __setobj__(__getobj__.deduplicate)
+            @extra = -extra if extra
+            super
+          end
       end
     end
   end
diff --git a/activerecord/lib/active_record/connection_adapters/postgresql/column.rb b/activerecord/lib/active_record/connection_adapters/postgresql/column.rb
index ec25bb1e19..f1ecf6df30 100644
--- a/activerecord/lib/active_record/connection_adapters/postgresql/column.rb
+++ b/activerecord/lib/active_record/connection_adapters/postgresql/column.rb
@@ -23,6 +23,29 @@ module ActiveRecord
         def sql_type
           super.sub(/\[\]\z/, "")
         end
+
+        def init_with(coder)
+          @serial = coder["serial"]
+          super
+        end
+
+        def encode_with(coder)
+          coder["serial"] = @serial
+          super
+        end
+
+        def ==(other)
+          other.is_a?(Column) &&
+            super &&
+            serial? == other.serial?
+        end
+        alias :eql? :==
+
+        def hash
+          Column.hash ^
+            super.hash ^
+            serial?.hash
+        end
       end
     end
     PostgreSQLColumn = PostgreSQL::Column # :nodoc:
diff --git a/activerecord/lib/active_record/connection_adapters/postgresql/type_metadata.rb b/activerecord/lib/active_record/connection_adapters/postgresql/type_metadata.rb
index 8bdec623af..b7f6479357 100644
--- a/activerecord/lib/active_record/connection_adapters/postgresql/type_metadata.rb
+++ b/activerecord/lib/active_record/connection_adapters/postgresql/type_metadata.rb
@@ -7,6 +7,8 @@ module ActiveRecord
       class TypeMetadata < DelegateClass(SqlTypeMetadata)
         undef to_yaml if method_defined?(:to_yaml)
 
+        include Deduplicable
+
         attr_reader :oid, :fmod
 
         def initialize(type_metadata, oid: nil, fmod: nil)
@@ -29,6 +31,12 @@ module ActiveRecord
             oid.hash ^
             fmod.hash
         end
+
+        private
+          def deduplicated
+            __setobj__(__getobj__.deduplicate)
+            super
+          end
       end
     end
     PostgreSQLTypeMetadata = PostgreSQL::TypeMetadata
diff --git a/activerecord/lib/active_record/connection_adapters/schema_cache.rb b/activerecord/lib/active_record/connection_adapters/schema_cache.rb
index dbfe1e4a34..7d54fcf9a0 100644
--- a/activerecord/lib/active_record/connection_adapters/schema_cache.rb
+++ b/activerecord/lib/active_record/connection_adapters/schema_cache.rb
@@ -27,7 +27,6 @@ module ActiveRecord
 
       def encode_with(coder)
         coder["columns"]          = @columns
-        coder["columns_hash"]     = @columns_hash
         coder["primary_keys"]     = @primary_keys
         coder["data_sources"]     = @data_sources
         coder["indexes"]          = @indexes
@@ -37,12 +36,13 @@ module ActiveRecord
 
       def init_with(coder)
         @columns          = coder["columns"]
-        @columns_hash     = coder["columns_hash"]
         @primary_keys     = coder["primary_keys"]
         @data_sources     = coder["data_sources"]
         @indexes          = coder["indexes"] || {}
         @version          = coder["version"]
         @database_version = coder["database_version"]
+
+        derive_columns_hash_and_deduplicate_values
       end
 
       def primary_keys(table_name)
@@ -79,9 +79,7 @@ module ActiveRecord
       # Get the columns for a table as a hash, key is the column name
       # value is the column object.
       def columns_hash(table_name)
-        @columns_hash[table_name] ||= Hash[columns(table_name).map { |col|
-          [col.name, col]
-        }]
+        @columns_hash[table_name] ||= columns(table_name).index_by(&:name)
       end
 
       # Checks whether the columns hash is already cached for a table.
@@ -124,15 +122,38 @@ module ActiveRecord
       def marshal_dump
         # if we get current version during initialization, it happens stack over flow.
         @version = connection.migration_context.current_version
-        [@version, @columns, @columns_hash, @primary_keys, @data_sources, @indexes, database_version]
+        [@version, @columns, {}, @primary_keys, @data_sources, @indexes, database_version]
       end
 
       def marshal_load(array)
-        @version, @columns, @columns_hash, @primary_keys, @data_sources, @indexes, @database_version = array
-        @indexes = @indexes || {}
+        @version, @columns, _columns_hash, @primary_keys, @data_sources, @indexes, @database_version = array
+        @indexes ||= {}
+
+        derive_columns_hash_and_deduplicate_values
       end
 
       private
+        def derive_columns_hash_and_deduplicate_values
+          @columns      = deep_deduplicate(@columns)
+          @columns_hash = @columns.transform_values { |columns| columns.index_by(&:name) }
+          @primary_keys = deep_deduplicate(@primary_keys)
+          @data_sources = deep_deduplicate(@data_sources)
+          @indexes      = deep_deduplicate(@indexes)
+        end
+
+        def deep_deduplicate(value)
+          case value
+          when Hash
+            value.transform_keys { |k| deep_deduplicate(k) }.transform_values { |v| deep_deduplicate(v) }
+          when Array
+            value.map { |i| deep_deduplicate(i) }
+          when String, Deduplicable
+            -value
+          else
+            value
+          end
+        end
+
         def prepare_data_sources
           connection.data_sources.each { |source| @data_sources[source] = true }
         end
diff --git a/activerecord/lib/active_record/connection_adapters/sql_type_metadata.rb b/activerecord/lib/active_record/connection_adapters/sql_type_metadata.rb
index df28df7a7c..969867e70f 100644
--- a/activerecord/lib/active_record/connection_adapters/sql_type_metadata.rb
+++ b/activerecord/lib/active_record/connection_adapters/sql_type_metadata.rb
@@ -1,9 +1,13 @@
 # frozen_string_literal: true
 
+require "active_record/connection_adapters/deduplicable"
+
 module ActiveRecord
   # :stopdoc:
   module ConnectionAdapters
     class SqlTypeMetadata
+      include Deduplicable
+
       attr_reader :sql_type, :type, :limit, :precision, :scale
 
       def initialize(sql_type: nil, type: nil, limit: nil, precision: nil, scale: nil)
@@ -32,6 +36,12 @@ module ActiveRecord
           precision.hash >> 1 ^
           scale.hash >> 2
       end
+
+      private
+        def deduplicated
+          @sql_type = -sql_type
+          super
+        end
     end
   end
 end
diff --git a/activerecord/lib/active_record/connection_adapters/sqlite3_adapter.rb b/activerecord/lib/active_record/connection_adapters/sqlite3_adapter.rb
index 3a1edfc855..f4847eb6c0 100644
--- a/activerecord/lib/active_record/connection_adapters/sqlite3_adapter.rb
+++ b/activerecord/lib/active_record/connection_adapters/sqlite3_adapter.rb
@@ -393,6 +393,7 @@ module ActiveRecord
             if from_primary_key.is_a?(Array)
               @definition.primary_keys from_primary_key
             end
+
             columns(from).each do |column|
               column_name = options[:rename] ?
                 (options[:rename][column.name] ||