Need package/description check for UWP exports in can_export()

[crazychenz]

Godot version: Godot 3.2.1.stable Windows 64 (non-mono)

OS/device including version:
Microsoft Windows [Version 10.0.19041.207] (build 2004) 64bit

Issue description:
When creating a new export configuration for UWP, there are a number of fields that are indicated as required or invalid before you can export. Currently there is a discrepancy between these checks and reality, where you can not install a signed APPX file if the description length is 0. Therefore, there should be an additional check added to platform/uwp/export/export.cpp:can_export() that checks that the "package/description" field length is greater than zero.

Steps to reproduce:

1. Create a do nothing project with a single node scene. Create an export configuration that satisfies all the settings while keeping the description blank.
2. Export UWP/APPX
3. Sign the APPX with signtool as indicated by the Godot documentation
4. Install the APPX via Powershell: Add-AppxPackage C:\path\project.appx

This description requirement can be seen enforced (via XML schema verification) in the Powershell Add-AppxPackage cmdlet:

Add-AppxPackage : Deployment failed with HRESULT: 0x80080204, The Appx package's manifest is invalid.
error 0xC00CE169: App manifest validation error: The app manifest must be valid as per schema: Line 19, Column 147,
Reason: '' violates minLength constraint of '1'.
The attribute 'Description' with value '' failed to parse.
NOTE: For additional information, look for [ActivityId] 25eed3ef-1376-0005-5d5c-81267613d601 in the Event Log or use
the command line Get-AppPackageLog -ActivityID 25eed3ef-1376-0005-5d5c-81267613d601
At line:1 char:1
+ Add-AppxPackage C:\projects\playground\NullProject\NullProject.appx
+ ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
    + CategoryInfo          : NotSpecified: (C:\projects\pla...ullProject.appx:String) [Add-AppxPackage], Exception
    + FullyQualifiedErrorId : DeploymentError,Microsoft.Windows.Appx.PackageManager.Commands.AddAppxPackageCommand

[GeorgeS2019]

@crazychenz @Calinou => it will be great to get the latest update the feasibility to export UWP in 3.2.2. Is there a plan? when will that be possible? Is there someone allocated to work on UWP?

[Calinou]

@GeorgeS2019 The UWP export barely gets any testing and maintenance due to lack of manpower (and it being a difficult platform to work with). As far as I know, there is no dedicated UWP maintainer.

[GeorgeS2019]

@Calinou @akien-mga This is the impression I have. However, since many new guys who have not followed the story of UWP since e.g. May 2019, they wasted their time. (I also aware UWP is on Juan TodoList from the 200K Epic Grant)

However, occasionally we have some recent effort in this area (e.g. UWP for ARM, make sense for Hololens 2.0), it is unclear HOW COMMITTED are we into delivering UWP for ARM. We need to have a clear message, because next two to three weeks, it is the best time to update Microsoft that Godot is on track to support hololens eventually (Especially @NeoSpark314 of Godot Discord) just delivered a PoC on Mixed Reality Capture using Oculus Quest.

A new development that will surely attract further Microsoft commitment to Godot.

[CreggHancock]

I was looking into this, and need some advice on something. Getting the description length check in is easy enough, but it seems that many of the manifest rules are currently not being enforced. Most of the names have min and max length requirements, and there are some that have specifications specific to their individual entry in the manifest (such as only allowing alpha-numeric characters). Do we want to enforce those rules as well, or is the focus specifically to notify users that they need something in their package/description box?

[Calinou]

I was looking into this, and need some advice on something. Getting the description length check in is easy enough, but it seems that many of the manifest rules are currently not being enforced. Most of the names have min and max length requirements, and there are some that have specifications specific to their individual entry in the manifest (such as only allowing alpha-numeric characters). Do we want to enforce those rules as well, or is the focus specifically to notify users that they need something in their package/description box?

I think we should try to enforce all rules directly in the Export dialog to avoid mistakes.