From 77d7d3aef6079515ce4c6345f631d24f60588291 Mon Sep 17 00:00:00 2001
From: Rahix <rahix@rahix.de>
Date: Sun, 5 Oct 2025 18:59:47 +0200
Subject: [PATCH] Introduce a digest epoch

To add a mechanism for updating all issue comments after a code change,
introduce a HASH_EPOCH constant which gets mixed into the stable hash
for each issue.  Changing this value will force all issue comments to be
updated.
---
 techtree-manager/src/tree.rs | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/techtree-manager/src/tree.rs b/techtree-manager/src/tree.rs
index fef523d..db6a93f 100644
--- a/techtree-manager/src/tree.rs
+++ b/techtree-manager/src/tree.rs
@@ -2,6 +2,8 @@ use std::collections::BTreeMap;
 
 use petgraph::visit::EdgeRef as _;
 
+const HASH_EPOCH: u32 = 0x00000001;
+
 /// Element in the techtree
 #[derive(Debug, Clone, Hash, PartialEq, Eq, serde::Serialize)]
 pub struct Element {
@@ -420,7 +422,7 @@ impl<'a> Subtree<'a> {
             .collect();
         edges.sort();
 
-        let json_data = serde_json::ser::to_string(&(nodes, edges)).unwrap();
+        let json_data = serde_json::ser::to_string(&(nodes, edges, HASH_EPOCH)).unwrap();
         sha256::digest(json_data)
     }
 }