Possible infinite loop in isChildOf

[philips77]

In the isChildOf() method there is a risk of an infinite loop, if the groups point form a cyclic references:

IOS-nRF-Mesh-Library/nRFMeshProvision/Classes/Mesh API/Group+MeshNetwork.swift

Lines 97 to 106 in 12e8332

	func isChildOf(_ parent: Group) -> Bool {
	var group: Group = self
	while let p = group.parent {
	if p == parent {
	return true
	}
	group = p
	}
	return false
	}

Cyclic groups should be checked on importing and setting a parent.

Note

Nested groups are not used in the sample app and not really well tested. The point of having nested groups is unclear to me, as this only comes in the CDB spec, not in the Mesh Profile. So this is only a way of organizing groups for the user.

[philips77]

The cyclic references should be checked here:

IOS-nRF-Mesh-Library/nRFMeshProvision/Classes/Mesh Model/Group.swift

Lines 56 to 77 in 12e8332

	public var parent: Group? {
	get {
	guard let meshNetwork = meshNetwork else {
	return nil
	}
	if parentAddress == "0000" {
	return nil
	}
	return meshNetwork.groups.first {
	$0.groupAddress == parentAddress
	}
	}
	set {
	guard let parent = newValue else {
	parentAddress = "0000"
	return
	}
	if let meshNetwork = meshNetwork, meshNetwork.groups.contains(parent) {
	parentAddress = parent.groupAddress
	}
	}
	}