Rollback workflow already completed error (uber#4209)

common/client/versionChecker.go

@@ -176,6 +176,7 @@ func (vc *versionChecker) SupportsRawHistoryQuery(clientImpl string, clientFeatu
 
 // Returns error if workflowAlreadyCompletedError is not supported otherwise nil.
 // In case client version lookup fails assume the client does not support feature.
+// NOTE: Enabling this error will break customer code handling the workflow errors in their workflow
 func (vc *versionChecker) SupportsWorkflowAlreadyCompletedError(clientImpl string, clientFeatureVersion string) error {
 	return vc.featureSupported(clientImpl, clientFeatureVersion, workflowAlreadyCompletedError)
 }

host/signalworkflowTest.go

@@ -225,7 +225,7 @@ func (s *IntegrationSuite) TestSignalWorkflow() {
 		Identity:   identity,
 	})
 	s.NotNil(err)
-	s.IsType(&types.WorkflowExecutionAlreadyCompletedError{}, err)
+	s.IsType(&types.EntityNotExistsError{}, err)
 }
 
 func (s *IntegrationSuite) TestSignalWorkflow_DuplicateRequest() {

service/frontend/workflowHandler.go

@@ -4159,6 +4159,8 @@ func checkRequiredDomainDataKVs(requiredDomainDataKeys map[string]interface{}, d
 func (wh *WorkflowHandler) normalizeVersionedErrors(ctx context.Context, err error) error {
 	switch err.(type) {
 	case *types.WorkflowExecutionAlreadyCompletedError:
+		return &types.EntityNotExistsError{Message: "Workflow execution already completed."}
+		/* TODO: re-enable the block below once we can rollout this *breaking* change
 		call := yarpc.CallFromContext(ctx)
 		clientFeatureVersion := call.Header(common.FeatureVersionHeaderName)
 		clientImpl := call.Header(common.ClientImplHeaderName)
@@ -4168,6 +4170,7 @@ func (wh *WorkflowHandler) normalizeVersionedErrors(ctx context.Context, err err
 		} else {
 			return &types.EntityNotExistsError{Message: "Workflow execution already completed."}
 		}
+		*/
 	default:
 		return err
 	}