[API] Subscribing user to issue produces nil in API reponse

[realaravinth]

Gitea Version

743-g7cc44491f

Git Version

No response

Operating System

No response

How are you running Gitea?

Tested on https://try.gitea.io

Database

No response

Can you reproduce the bug on the Gitea demo site?

Yes

Log Gist

No response

Description

When subscribing a user through the API to an issue, it returns the following error when the operation is forbidden:

{
  "message": "%!s(<nil>)",
  "url": "https://try.gitea.io/api/swagger"
}

This is probably harmless but can be fixed to return an appropriate error message like so:

{
 "message": "Only admin and user for itself can change subscription",
"url": "https://try.gitea.io/api/swagger"
}

The problem seems to be in this line:

gitea/routers/api/v1/repo/issue_subscription.go

Line 131 in 7cc4449

ctx.Error(http.StatusForbidden, "User", nil)

I'll be happy to submit a patch to this effect!

Screenshots

[zeripath]

This can only occur if you're trying to subscribe a user that isn't the logged in user or you're not the admin.

It will be coming from

	//only admin and user for itself can change subscription
	if user.ID != ctx.User.ID && !ctx.User.IsAdmin {
		ctx.Error(http.StatusForbidden, "User", nil)
		return
	}

[realaravinth]

The error(403 forbidden) is alright and is working according to spec but I was referring to the message. It's a minor thing but a descriptive error message might come in handy while debugging