1 files changed, 23 insertions, 15 deletions
diff --git a/activerecord/lib/active_record/errors.rb b/activerecord/lib/active_record/errors.rb
index 718f04871d..6721fe144f 100644
--- a/activerecord/lib/active_record/errors.rb
+++ b/activerecord/lib/active_record/errors.rb
@@ -63,7 +63,7 @@ module ActiveRecord
   class RecordNotSaved < ActiveRecordError
     attr_reader :record
 
-    def initialize(message, record = nil)
+    def initialize(message = nil, record = nil)
       @record = record
       super(message)
     end
@@ -80,7 +80,7 @@ module ActiveRecord
   class RecordNotDestroyed < ActiveRecordError
     attr_reader :record
 
-    def initialize(message, record = nil)
+    def initialize(message = nil, record = nil)
       @record = record
       super(message)
     end
@@ -92,9 +92,9 @@ module ActiveRecord
   class StatementInvalid < ActiveRecordError
     attr_reader :original_exception
 
-    def initialize(message, original_exception = nil)
-      super(message)
+    def initialize(message = nil, original_exception = nil)
       @original_exception = original_exception
+      super(message)
     end
   end
 
@@ -134,10 +134,14 @@ module ActiveRecord
   class StaleObjectError < ActiveRecordError
     attr_reader :record, :attempted_action
 
-    def initialize(record, attempted_action)
-      super("Attempted to #{attempted_action} a stale object: #{record.class.name}")
-      @record = record
-      @attempted_action = attempted_action
+    def initialize(record = nil, attempted_action = nil)
+      if record && attempted_action
+        @record = record
+        @attempted_action = attempted_action
+        super("Attempted to #{attempted_action} a stale object: #{record.class.name}.")
+      else
+        super("Stale object error.")
+      end
     end
 
   end
@@ -196,7 +200,7 @@ module ActiveRecord
   class AttributeAssignmentError < ActiveRecordError
     attr_reader :exception, :attribute
 
-    def initialize(message, exception, attribute)
+    def initialize(message = nil, exception = nil, attribute = nil)
       super(message)
       @exception = exception
       @attribute = attribute
@@ -209,7 +213,7 @@ module ActiveRecord
   class MultiparameterAssignmentErrors < ActiveRecordError
     attr_reader :errors
 
-    def initialize(errors)
+    def initialize(errors = nil)
       @errors = errors
     end
   end
@@ -218,11 +222,15 @@ module ActiveRecord
   class UnknownPrimaryKey < ActiveRecordError
     attr_reader :model
 
-    def initialize(model, description = nil)
-      message = "Unknown primary key for table #{model.table_name} in model #{model}."
-      message += "\n#{description}" if description
-      super(message)
-      @model = model
+    def initialize(model = nil, description = nil)
+      if model
+        message = "Unknown primary key for table #{model.table_name} in model #{model}."
+        message += "\n#{description}" if description
+        @model = model
+        super(message)
+      else
+        super("Unknown primary key.")
+      end
     end
   end