1 files changed, 41 insertions, 2 deletions
diff --git a/src/access/screen.rs b/src/access/screen.rs
index aa16b42..ae61416 100644
--- a/src/access/screen.rs
+++ b/src/access/screen.rs
@@ -433,7 +433,7 @@ pub(crate) fn apply(
                 if relevant(&paths[index]) || reaches_signed(doc, &paths[index]) {
                     // What rules read changed: in before the next is judged.
                     screened.applied += accepted.len();
-                    doc.apply_changes_log_patches(std::mem::take(&mut accepted), log)?;
+                    apply_taken(doc, std::mem::take(&mut accepted), log)?;
                     frontier.clear();
                 } else {
                     frontier.insert(hash, seen_at);
@@ -460,7 +460,7 @@ pub(crate) fn apply(
     }
     screened.applied += accepted.len();
     if !accepted.is_empty() {
-        doc.apply_changes_log_patches(accepted, log)?;
+        apply_taken(doc, accepted, log)?;
     }
     for (hash, root) in refused {
         refusals.insert(hash, root);
@@ -473,6 +473,45 @@ pub(crate) fn apply(
     Ok(screened)
 }
 
+/// `accepted` applied to `doc`. Automerge takes them all or none: one it won't take (a
+/// fork of an actor's changes, under a policy without signatures) fails the lot, so the
+/// error names them (the first few), with the node each says made it, for the log of
+/// whoever brought them.
+fn apply_taken(
+    doc: &mut Document,
+    accepted: Vec<Change>,
+    log: &mut crate::document::PatchLog,
+) -> Result<()> {
+    const NAMED: usize = 8;
+    let count = accepted.len();
+    let mut named: Vec<String> = accepted
+        .iter()
+        .take(NAMED)
+        .map(|change| {
+            let author = change
+                .author()
+                .and_then(|author| {
+                    std::str::from_utf8(author.as_bytes())
+                        .ok()
+                        .map(str::to_owned)
+                })
+                .unwrap_or_else(|| "its actor's node".to_owned());
+            format!("{} (seq {} by {author})", change.hash(), change.seq())
+        })
+        .collect();
+    if count > NAMED {
+        named.push(format!("{} more", count - NAMED));
+    }
+    doc.apply_changes_log_patches(accepted, log)
+        .map_err(|error| {
+            anyhow::anyhow!(
+                "Automerge took none of the {count} changes judged: {error} ({})",
+                named.join(", ")
+            )
+        })?;
+    Ok(())
+}
+
 /// What `apply_bytes` did.
 #[derive(Debug, Default, Clone)]
 pub(crate) struct Outcome {