Merge branch 'master' into db_system_change_command

14 files changed, 65 insertions, 84 deletions

diff --git a/activerecord/lib/active_record/associations.rb b/activerecord/lib/active_record/associations.rb
index fb1df00dc8..7bdbd8ce69 100644
--- a/activerecord/lib/active_record/associations.rb
+++ b/activerecord/lib/active_record/associations.rb
@@ -1293,7 +1293,8 @@ module ActiveRecord
         #
         #   * <tt>:destroy</tt> causes all the associated objects to also be destroyed.
         #   * <tt>:delete_all</tt> causes all the associated objects to be deleted directly from the database (so callbacks will not be executed).
-        #   * <tt>:nullify</tt> causes the foreign keys to be set to +NULL+. Callbacks are not executed.
+        #   * <tt>:nullify</tt> causes the foreign keys to be set to +NULL+. Polymorphic type will also be nullified
+        #     on polymorphic associations. Callbacks are not executed.
         #   * <tt>:restrict_with_exception</tt> causes an <tt>ActiveRecord::DeleteRestrictionError</tt> exception to be raised if there are any associated records.
         #   * <tt>:restrict_with_error</tt> causes an error to be added to the owner if there are any associated objects.
         #
@@ -1436,7 +1437,8 @@ module ActiveRecord
         #
         #   * <tt>:destroy</tt> causes the associated object to also be destroyed
         #   * <tt>:delete</tt> causes the associated object to be deleted directly from the database (so callbacks will not execute)
-        #   * <tt>:nullify</tt> causes the foreign key to be set to +NULL+. Callbacks are not executed.
+        #   * <tt>:nullify</tt> causes the foreign key to be set to +NULL+. Polymorphic type column is also nullified
+        #     on polymorphic associations. Callbacks are not executed.
         #   * <tt>:restrict_with_exception</tt> causes an <tt>ActiveRecord::DeleteRestrictionError</tt> exception to be raised if there is an associated record
         #   * <tt>:restrict_with_error</tt> causes an error to be added to the owner if there is an associated object
         #
diff --git a/activerecord/lib/active_record/associations/foreign_association.rb b/activerecord/lib/active_record/associations/foreign_association.rb
index 40010cde03..59af6f54c3 100644
--- a/activerecord/lib/active_record/associations/foreign_association.rb
+++ b/activerecord/lib/active_record/associations/foreign_association.rb
@@ -9,5 +9,12 @@ module ActiveRecord::Associations
         false
       end
     end
+
+    def nullified_owner_attributes
+      Hash.new.tap do |attrs|
+        attrs[reflection.foreign_key] = nil
+        attrs[reflection.type] = nil if reflection.type.present?
+      end
+    end
   end
 end
diff --git a/activerecord/lib/active_record/associations/has_many_association.rb b/activerecord/lib/active_record/associations/has_many_association.rb
index f6fdbcde54..eb22db838c 100644
--- a/activerecord/lib/active_record/associations/has_many_association.rb
+++ b/activerecord/lib/active_record/associations/has_many_association.rb
@@ -92,7 +92,7 @@ module ActiveRecord
           if method == :delete_all
             scope.delete_all
           else
-            scope.update_all(reflection.foreign_key => nil)
+            scope.update_all(nullified_owner_attributes)
           end
         end
 
diff --git a/activerecord/lib/active_record/associations/has_one_association.rb b/activerecord/lib/active_record/associations/has_one_association.rb
index 390bfd8b08..99971286a3 100644
--- a/activerecord/lib/active_record/associations/has_one_association.rb
+++ b/activerecord/lib/active_record/associations/has_one_association.rb
@@ -33,7 +33,7 @@ module ActiveRecord
             target.destroy
             throw(:abort) unless target.destroyed?
           when :nullify
-            target.update_columns(reflection.foreign_key => nil) if target.persisted?
+            target.update_columns(nullified_owner_attributes) if target.persisted?
           end
         end
       end
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 2299fc0214..79d71bfb5d 100644
--- a/activerecord/lib/active_record/connection_adapters/abstract/database_statements.rb
+++ b/activerecord/lib/active_record/connection_adapters/abstract/database_statements.rb
@@ -123,7 +123,7 @@ module ActiveRecord
       # +binds+ as the bind substitutes. +name+ is logged along with
       # the executed +sql+ statement.
       def exec_insert(sql, name = nil, binds = [], pk = nil, sequence_name = nil)
-        sql, binds = sql_for_insert(sql, pk, nil, sequence_name, binds)
+        sql, binds = sql_for_insert(sql, pk, sequence_name, binds)
         exec_query(sql, name, binds)
       end
 
@@ -464,7 +464,7 @@ module ActiveRecord
           exec_query(sql, name, binds, prepare: true)
         end
 
-        def sql_for_insert(sql, pk, id_value, sequence_name, binds)
+        def sql_for_insert(sql, pk, sequence_name, binds)
           [sql, binds]
         end
 
diff --git a/activerecord/lib/active_record/connection_adapters/abstract_adapter.rb b/activerecord/lib/active_record/connection_adapters/abstract_adapter.rb
index 346d4b067a..d1ff32df3f 100644
--- a/activerecord/lib/active_record/connection_adapters/abstract_adapter.rb
+++ b/activerecord/lib/active_record/connection_adapters/abstract_adapter.rb
@@ -6,6 +6,7 @@ require "active_record/connection_adapters/sql_type_metadata"
 require "active_record/connection_adapters/abstract/schema_dumper"
 require "active_record/connection_adapters/abstract/schema_creation"
 require "active_support/concurrency/load_interlock_aware_monitor"
+require "active_support/deprecation"
 require "arel/collectors/bind"
 require "arel/collectors/composite"
 require "arel/collectors/sql_string"
@@ -76,8 +77,11 @@ module ActiveRecord
 
       SIMPLE_INT = /\A\d+\z/
 
-      attr_accessor :visitor, :pool, :prevent_writes
-      attr_reader :schema_cache, :owner, :logger, :prepared_statements, :lock
+      attr_writer :visitor
+      deprecate :visitor=
+
+      attr_accessor :pool
+      attr_reader :schema_cache, :visitor, :owner, :logger, :lock, :prepared_statements, :prevent_writes
       alias :in_use? :owner
 
       set_callback :checkin, :after, :enable_lazy_transactions!
@@ -117,6 +121,7 @@ module ActiveRecord
         @idle_since          = Concurrent.monotonic_time
         @schema_cache        = SchemaCache.new self
         @quoted_column_names, @quoted_table_names = {}, {}
+        @prevent_writes = false
         @visitor = arel_visitor
         @lock = ActiveSupport::Concurrency::LoadInterlockAwareMonitor.new
 
@@ -152,11 +157,10 @@ module ActiveRecord
       # even if you are on a database that can write. `while_preventing_writes`
       # will prevent writes to the database for the duration of the block.
       def while_preventing_writes
-        original = self.prevent_writes
-        self.prevent_writes = true
+        original, @prevent_writes = @prevent_writes, true
         yield
       ensure
-        self.prevent_writes = original
+        @prevent_writes = original
       end
 
       def migrations_paths # :nodoc:
@@ -504,15 +508,17 @@ module ActiveRecord
         @connection
       end
 
-      def case_sensitive_comparison(table, attribute, column, value) # :nodoc:
-        table[attribute].eq(value)
+      def case_sensitive_comparison(attribute, value) # :nodoc:
+        attribute.eq(value)
       end
 
-      def case_insensitive_comparison(table, attribute, column, value) # :nodoc:
+      def case_insensitive_comparison(attribute, value) # :nodoc:
+        column = column_for_attribute(attribute)
+
         if can_perform_case_insensitive_comparison_for?(column)
-          table[attribute].lower.eq(table.lower(value))
+          attribute.lower.eq(attribute.relation.lower(value))
         else
-          table[attribute].eq(value)
+          attribute.eq(value)
         end
       end
 
@@ -659,6 +665,11 @@ module ActiveRecord
             raise(ActiveRecordError, "No such column: #{table_name}.#{column_name}")
         end
 
+        def column_for_attribute(attribute)
+          table_name = attribute.relation.name
+          schema_cache.columns_hash(table_name)[attribute.name.to_s]
+        end
+
         def collector
           if prepared_statements
             Arel::Collectors::Composite.new(
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 cccd6e2210..70d281b62b 100644
--- a/activerecord/lib/active_record/connection_adapters/abstract_mysql_adapter.rb
+++ b/activerecord/lib/active_record/connection_adapters/abstract_mysql_adapter.rb
@@ -476,9 +476,11 @@ module ActiveRecord
         SQL
       end
 
-      def case_sensitive_comparison(table, attribute, column, value) # :nodoc:
+      def case_sensitive_comparison(attribute, value) # :nodoc:
+        column = column_for_attribute(attribute)
+
         if column.collation && !column.case_sensitive?
-          table[attribute].eq(Arel::Nodes::Bin.new(value))
+          attribute.eq(Arel::Nodes::Bin.new(value))
         else
           super
         end
diff --git a/activerecord/lib/active_record/connection_adapters/postgresql/database_statements.rb b/activerecord/lib/active_record/connection_adapters/postgresql/database_statements.rb
index c70a4fa875..41633872e2 100644
--- a/activerecord/lib/active_record/connection_adapters/postgresql/database_statements.rb
+++ b/activerecord/lib/active_record/connection_adapters/postgresql/database_statements.rb
@@ -110,7 +110,7 @@ module ActiveRecord
         end
         alias :exec_update :exec_delete
 
-        def sql_for_insert(sql, pk, id_value, sequence_name, binds) # :nodoc:
+        def sql_for_insert(sql, pk, sequence_name, binds) # :nodoc:
           if pk.nil?
             # Extract the table from the insert sql. Yuck.
             table_ref = extract_table_ref_from_insert_sql(sql)
diff --git a/activerecord/lib/active_record/relation.rb b/activerecord/lib/active_record/relation.rb
index ba221a333b..a863227276 100644
--- a/activerecord/lib/active_record/relation.rb
+++ b/activerecord/lib/active_record/relation.rb
@@ -44,6 +44,11 @@ module ActiveRecord
     end
 
     def bind_attribute(name, value) # :nodoc:
+      if reflection = klass._reflect_on_association(name)
+        name = reflection.foreign_key
+        value = value.read_attribute(reflection.klass.primary_key) unless value.nil?
+      end
+
       attr = arel_attribute(name)
       bind = predicate_builder.build_bind_attribute(attr.name, value)
       yield attr, bind
diff --git a/activerecord/lib/active_record/relation/finder_methods.rb b/activerecord/lib/active_record/relation/finder_methods.rb
index dc03b196f4..fd84f9c46b 100644
--- a/activerecord/lib/active_record/relation/finder_methods.rb
+++ b/activerecord/lib/active_record/relation/finder_methods.rb
@@ -312,6 +312,8 @@ module ActiveRecord
 
       return false if !conditions || limit_value == 0
 
+      conditions = sanitize_forbidden_attributes(conditions)
+
       if eager_loading?
         relation = apply_join_dependency(eager_loading: false)
         return relation.exists?(conditions)
diff --git a/activerecord/lib/active_record/validations/uniqueness.rb b/activerecord/lib/active_record/validations/uniqueness.rb
index 5a1dbc8e53..111b6c9a64 100644
--- a/activerecord/lib/active_record/validations/uniqueness.rb
+++ b/activerecord/lib/active_record/validations/uniqueness.rb
@@ -56,33 +56,21 @@ module ActiveRecord
       end
 
       def build_relation(klass, attribute, value)
-        if reflection = klass._reflect_on_association(attribute)
-          attribute = reflection.foreign_key
-          value = value.attributes[reflection.klass.primary_key] unless value.nil?
-        end
-
-        if value.nil?
-          return klass.unscoped.where!(attribute => value)
-        end
-
-        # the attribute may be an aliased attribute
-        if klass.attribute_alias?(attribute)
-          attribute = klass.attribute_alias(attribute)
+        relation = klass.unscoped
+        comparison = relation.bind_attribute(attribute, value) do |attr, bind|
+          return relation.none! unless bind.boundable?
+
+          if bind.nil?
+            attr.eq(bind)
+          elsif options[:case_sensitive]
+            klass.connection.case_sensitive_comparison(attr, bind)
+          else
+            # will use SQL LOWER function before comparison, unless it detects a case insensitive collation
+            klass.connection.case_insensitive_comparison(attr, bind)
+          end
         end
 
-        attribute_name = attribute.to_s
-        value = klass.predicate_builder.build_bind_attribute(attribute_name, value)
-
-        table = klass.arel_table
-        column = klass.columns_hash[attribute_name]
-
-        comparison = if !options[:case_sensitive]
-          # will use SQL LOWER function before comparison, unless it detects a case insensitive collation
-          klass.connection.case_insensitive_comparison(table, attribute, column, value)
-        else
-          klass.connection.case_sensitive_comparison(table, attribute, column, value)
-        end
-        klass.unscoped.where!(comparison)
+        relation.where!(comparison)
       end
 
       def scope_relation(record, relation)
diff --git a/activerecord/lib/arel.rb b/activerecord/lib/arel.rb
index dab785738e..7411b5c41b 100644
--- a/activerecord/lib/arel.rb
+++ b/activerecord/lib/arel.rb
@@ -13,7 +13,6 @@ require "arel/alias_predication"
 require "arel/order_predications"
 require "arel/table"
 require "arel/attributes"
-require "arel/compatibility/wheres"
 
 require "arel/visitors"
 require "arel/collectors/sql_string"
diff --git a/activerecord/lib/arel/compatibility/wheres.rb b/activerecord/lib/arel/compatibility/wheres.rb
deleted file mode 100644
index c8a73f0dae..0000000000
--- a/activerecord/lib/arel/compatibility/wheres.rb
+++ /dev/null
@@ -1,35 +0,0 @@
-# frozen_string_literal: true
-
-module Arel # :nodoc: all
-  module Compatibility # :nodoc:
-    class Wheres # :nodoc:
-      include Enumerable
-
-      module Value # :nodoc:
-        attr_accessor :visitor
-        def value
-          visitor.accept self
-        end
-
-        def name
-          super.to_sym
-        end
-      end
-
-      def initialize(engine, collection)
-        @engine     = engine
-        @collection = collection
-      end
-
-      def each
-        to_sql = Visitors::ToSql.new @engine
-
-        @collection.each { |c|
-          c.extend(Value)
-          c.visitor = to_sql
-          yield c
-        }
-      end
-    end
-  end
-end
diff --git a/activerecord/lib/arel/predications.rb b/activerecord/lib/arel/predications.rb
index 28679ae892..2a62c53aa3 100644
--- a/activerecord/lib/arel/predications.rb
+++ b/activerecord/lib/arel/predications.rb
@@ -36,14 +36,14 @@ module Arel # :nodoc: all
 
     def between(other)
       if infinity?(other.begin)
-        if infinity?(other.end)
+        if other.end.nil? || infinity?(other.end)
           not_in([])
         elsif other.exclude_end?
           lt(other.end)
         else
           lteq(other.end)
         end
-      elsif infinity?(other.end)
+      elsif other.end.nil? || infinity?(other.end)
         gteq(other.begin)
       elsif other.exclude_end?
         gteq(other.begin).and(lt(other.end))
@@ -82,14 +82,14 @@ Passing a range to `#in` is deprecated. Call `#between`, instead.
 
     def not_between(other)
       if infinity?(other.begin)
-        if infinity?(other.end)
+        if other.end.nil? || infinity?(other.end)
           self.in([])
         elsif other.exclude_end?
           gteq(other.end)
         else
           gt(other.end)
         end
-      elsif infinity?(other.end)
+      elsif other.end.nil? || infinity?(other.end)
         lt(other.begin)
       else
         left = lt(other.begin)