{
"name": "cycle-in-references",
"description": "An edge that would create a cycle is ignored and all visible messages remain output.",
"spec": {
"source": "JWZ",
"url": "https://www.jwz.org/doc/threading.html",
"behavior": "thread construction must avoid parent-child cycles"
},
"input": [
{
"id": "<cycle-a@example>",
"message_id": "<cycle-a@example>",
"in_reply_to": "<cycle-b@example>",
"references": [
"<cycle-b@example>"
],
"subject": "Cycle",
"date": "2026-05-15T09:00:00Z"
},
{
"id": "<cycle-b@example>",
"message_id": "<cycle-b@example>",
"in_reply_to": "<cycle-a@example>",
"references": [
"<cycle-a@example>"
],
"subject": "Re: Cycle",
"date": "2026-05-15T09:05:00Z"
}
],
"expected": {
"threads": [
{
"root": "<cycle-b@example>",
"messages": [
"<cycle-a@example>",
"<cycle-b@example>"
]
}
]
}
}