1 files changed, 26 insertions, 17 deletions
diff --git a/activerecord/lib/active_record/connection_adapters/abstract_adapter.rb b/activerecord/lib/active_record/connection_adapters/abstract_adapter.rb
index f7d75e6748..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
 
@@ -146,17 +151,16 @@ module ActiveRecord
         replica? || prevent_writes
       end
 
-      # Prevent writing to the database  regardless of role.
+      # Prevent writing to the database regardless of role.
       #
       # In some cases you may want to prevent writes to the database
       # 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
 
@@ -631,13 +637,11 @@ module ActiveRecord
             statement_name:    statement_name,
             connection_id:     object_id,
             connection:        self) do
-            begin
-              @lock.synchronize do
-                yield
-              end
-            rescue => e
-              raise translate_exception_class(e, sql, binds)
+            @lock.synchronize do
+              yield
             end
+          rescue => e
+            raise translate_exception_class(e, sql, binds)
           end
         end
 
@@ -661,6 +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(