naming error in multiple blend file

[ederenn]

Description

Golem Version: 0.22.0

Golem-Messages version (leave empty if unsure): 3.14.1

Electron version: 0.2.4

OS [e.g. Windows 10 Pro]: Any

Branch (if launched from source): -

Mainnet/Testnet: mainnet

Priority label is set to the lowest by default. To setup higher priority please change the label
P0 label is set for Severity-Critical/Effort-easy
P1 label is set for Severity-Critical/Effort-hard
P2 label is set for Severity-Low/ Effort-easy
P3 label is set for Severity-Low/Effort-hard

Description of the issue:

When name of main scene file in multiple blender task is shorter than 4 letters Golem allows to upload it but the interface hangs in testing local render. In logs appears an error Test task error: Length of task name cannot be less than 4 or more than 24 characters.

Actual result:

It is not possible to start a task

Screenshots:

Steps To Reproduce

Short description of steps to reproduce the behavior:
e.g.

1. Launch the Golem
2. Upload a multiblend file. Should contain a main file scene named with 3 letters or less.
3. Choose it as a main file, click next
4. Leave the name unchanged in Name your task tab, click next
5. Interface will hang on testing local render.
6. Check logs for error

Expected behavior

App should allow shorter names or give a warning in interface that is not permitted to name a file with less than 4 characters.

Logs and any additional context

2020-01-28 16:44:23 INFO     golem.client                        Loading presets for Blender 
2020-01-28 16:44:23 INFO     golem.task.rpc                      Running test task "{'name': 'new', 'resources': ['/home/ederenn/Desktop/scena-prosta/assets/ball.blend', '/home/ederenn/Desktop/scena-prosta/assets/cube.blend', '/home/ederenn/Desktop/scena-prosta/new.blend', '/home/ederenn/Desktop/scena-prosta/new.png', '/home/ederenn/Desktop/scena-prosta/new2.blend', '/home/ederenn/Desktop/scena-prosta/textures/base_brightWood.png', '/home/ederenn/Desktop/scena-prosta/textures/base_leather.jpg', '/home/ederenn/Desktop/scena-prosta/textures/base_woodFloor.jpg'], 'compute_on': 'cpu', 'type': 'Blender', 'subtasks_count': 1}" ... 
2020-01-28 16:44:23 ERROR    golem.task.rpc                      Test task error: Length of task name cannot be less than 4 or more than 24 characters. 

Proposed Solution?

(Optional: What could be a solution for that issue)