1 files changed, 16 insertions, 11 deletions

diff --git a/vrsite/jj.go b/vrsite/jj.go
index bb95d83..0b5cbdf 100644
--- a/vrsite/jj.go
+++ b/vrsite/jj.go
@@ -1,9 +1,8 @@
 // jj.go — every read of the repository goes through here.
 //
-// Two rules hold everywhere: the repo is never modified (no edit, no new, no
-// checkout; --ignore-working-copy on every call so we never even snapshot),
-// and nothing is written to disk — templates are passed inline with -T, so a
-// query leaves no trace behind, it just renders once and is sent to the page.
+// These helpers never modify project history or its working copy
+// (--ignore-working-copy means they never even snapshot it). Sidecar mutation
+// is isolated in the shared sidecar package.
 package main
 
 import (
@@ -72,21 +71,27 @@ func checkRevset(r string) error {
 }
 
 func resolveChange(repo, rev string) (string, error) {
+	change, _, err := resolveRevision(repo, rev)
+	return change, err
+}
+
+func resolveRevision(repo, rev string) (change, commit string, err error) {
 	if rev == "" {
 		rev = "@"
 	}
 	if err := checkRevset(rev); err != nil {
-		return "", err
+		return "", "", err
 	}
-	out, err := jjRun(repo, "log", "-r", rev, "--no-graph", "-n", "1", "-T", "change_id")
+	out, err := jjRun(repo, "log", "-r", "exactly(("+rev+"), 1)", "--no-graph",
+		"-T", "change_id ++ \"\\n\" ++ commit_id ++ \"\\n\"")
 	if err != nil {
-		return "", err
+		return "", "", err
 	}
-	id := strings.TrimSpace(string(out))
-	if id == "" {
-		return "", fmt.Errorf("revset %q matches no change", rev)
+	ids := strings.Fields(string(out))
+	if len(ids) != 2 {
+		return "", "", fmt.Errorf("revset %q did not resolve to one change and commit", rev)
 	}
-	return id, nil
+	return ids[0], ids[1], nil
 }
 
 // changeBrief resolves a revset to the one change it names, with everything a