Store task errors following migrations and display them (#13246)

* Store task errors following migrations and display them

When migrate tasks fail store the error in the task table
and ensure that they show on the status page.

Fix #13242

Signed-off-by: Andrew Thornton <art27@cantab.net>

* Update web_src/js/index.js

* Hide the failed first

Signed-off-by: Andrew Thornton <art27@cantab.net>

Co-authored-by: techknowlogick <techknowlogick@gitea.io>

models/task.go

@@ -147,6 +147,27 @@ func GetMigratingTask(repoID int64) (*Task, error) {
 	return &task, nil
 }
 
+// GetMigratingTaskByID returns the migrating task by repo's id
+func GetMigratingTaskByID(id, doerID int64) (*Task, *migration.MigrateOptions, error) {
+	var task = Task{
+		ID:     id,
+		DoerID: doerID,
+		Type:   structs.TaskTypeMigrateRepo,
+	}
+	has, err := x.Get(&task)
+	if err != nil {
+		return nil, nil, err
+	} else if !has {
+		return nil, nil, ErrTaskDoesNotExist{id, 0, task.Type}
+	}
+
+	var opts migration.MigrateOptions
+	if err := json.Unmarshal([]byte(task.PayloadContent), &opts); err != nil {
+		return nil, nil, err
+	}
+	return &task, &opts, nil
+}
+
 // FindTaskOptions find all tasks
 type FindTaskOptions struct {
 	Status int