// patch4:
// - add Revert flag to in-progress revert-snap changes
// - move from had-candidate to old-candidate-index in link-snap tasks
// - add cleanup task to in-progress changes that have a copy-snap-data task
func patch4(s *state.State) error {
p4 := patch4T{}
for _, change := range s.Changes() {
// change is full done, take it easy
if change.Status().Ready() {
continue
}
if change.Kind() != "revert-snap" {
continue
}
for _, task := range change.Tasks() {
if err := p4.addRevertFlag(task); err != nil {
return err
}
}
}
for _, task := range s.Tasks() {
// change is full done, take it easy
if task.Change().Status().Ready() {
continue
}
switch task.Kind() {
case "link-snap":
if err := p4.mangle(task); err != nil {
return err
}
case "copy-snap-data":
if err := p4.addCleanup(task); err != nil {
return err
}
}
}
return nil
}