1 files changed, 26 insertions, 13 deletions
diff --git a/activerecord/lib/active_record/persistence.rb b/activerecord/lib/active_record/persistence.rb
index 8e749772a1..eed49e17b1 100644
--- a/activerecord/lib/active_record/persistence.rb
+++ b/activerecord/lib/active_record/persistence.rb
@@ -72,11 +72,9 @@ module ActiveRecord
     # +save+ returns +false+. See ActiveRecord::Callbacks for further
     # details.
     def save(*)
-      begin
-        create_or_update
-      rescue ActiveRecord::RecordInvalid
-        false
-      end
+      create_or_update
+    rescue ActiveRecord::RecordInvalid
+      false
     end
 
     # Saves the model.
@@ -155,7 +153,18 @@ module ActiveRecord
       became.instance_variable_set("@new_record", new_record?)
       became.instance_variable_set("@destroyed", destroyed?)
       became.instance_variable_set("@errors", errors)
-      became.public_send("#{klass.inheritance_column}=", klass.name) unless self.class.descends_from_active_record?
+      became
+    end
+
+    # Wrapper around +becomes+ that also changes the instance's sti column value.
+    # This is especially useful if you want to persist the changed class in your
+    # database.
+    #
+    # Note: The old instance's sti column value will be changed too, as both objects
+    # share the same set of attributes.
+    def becomes!(klass)
+      became = becomes(klass)
+      became.public_send("#{klass.inheritance_column}=", klass.sti_name) unless self.class.descends_from_active_record?
       became
     end
 
@@ -171,7 +180,7 @@ module ActiveRecord
       name = name.to_s
       verify_readonly_attribute(name)
       send("#{name}=", value)
-      save(:validate => false)
+      save(validate: false)
     end
 
     # Updates the attributes of the model from the passed-in hash and saves the
@@ -226,8 +235,8 @@ module ActiveRecord
 
       updated_count = self.class.where(self.class.primary_key => id).update_all(attributes)
 
-      attributes.each do |k,v|
-        raw_write_attribute(k,v)
+      attributes.each do |k, v|
+        raw_write_attribute(k, v)
       end
 
       updated_count == 1
@@ -379,10 +388,14 @@ module ActiveRecord
     # Returns the number of affected rows.
     def update(attribute_names = @attributes.keys)
       attributes_with_values = arel_attributes_with_values_for_update(attribute_names)
-      return 0 if attributes_with_values.empty?
-      klass = self.class
-      stmt = klass.unscoped.where(klass.arel_table[klass.primary_key].eq(id)).arel.compile_update(attributes_with_values)
-      klass.connection.update stmt
+
+      if attributes_with_values.empty?
+        0
+      else
+        klass = self.class
+        stmt = klass.unscoped.where(klass.arel_table[klass.primary_key].eq(id)).arel.compile_update(attributes_with_values)
+        klass.connection.update stmt
+      end
     end
 
     # Creates a record with values matching those of the instance attributes