From 44fc11dff88fe8dfc2e323d989e26d6cbd19f961 Mon Sep 17 00:00:00 2001
From: cloudhead <cloudhead@radicle.xyz>
Date: Wed, 17 Jan 2024 13:27:31 +0100
Subject: [PATCH] cob: Don't panic on missing root

This can happen if the change was not able to be loaded due to open file
limit issues for example.
---
 radicle-cob/src/change_graph.rs | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/radicle-cob/src/change_graph.rs b/radicle-cob/src/change_graph.rs
index 32f195ca..b8fe201e 100644
--- a/radicle-cob/src/change_graph.rs
+++ b/radicle-cob/src/change_graph.rs
@@ -17,6 +17,8 @@ pub enum EvaluateError {
     Init(Box<dyn std::error::Error + Sync + Send + 'static>),
     #[error("invalid signature for entry '{0}'")]
     Signature(EntryId),
+    #[error("root entry '{0}' missing from graph")]
+    MissingRoot(EntryId),
 }
 
 /// The graph of changes for a particular collaborative object
@@ -100,7 +102,7 @@ impl ChangeGraph {
         let root = self
             .graph
             .get(&root)
-            .expect("ChangeGraph::evaluate: root must be part of change graph");
+            .ok_or(EvaluateError::MissingRoot(root))?;
 
         if !root.valid_signatures() {
             return Err(EvaluateError::Signature(root.id));