1 files changed, 18 insertions, 0 deletions
diff --git a/vrsite/jj.go b/vrsite/jj.go
index 55f4795..bb95d83 100644
--- a/vrsite/jj.go
+++ b/vrsite/jj.go
@@ -89,6 +89,24 @@ func resolveChange(repo, rev string) (string, error) {
 	return id, nil
 }
 
+// changeBrief resolves a revset to the one change it names, with everything a
+// page says about it. One call answers both "which change" and "which commit
+// is under it right now" — the second is what content is cached against, since
+// a change id is a pointer and the commit beneath it is rewritten on every
+// edit.
+func changeBrief(repo, rev string) (Row, error) {
+	rows, err := LogRows(repo, rev, "", 1)
+	if err != nil {
+		return Row{}, err
+	}
+	for _, r := range rows {
+		if !r.Blank() {
+			return r, nil
+		}
+	}
+	return Row{}, fmt.Errorf("revset %q matches no change", rev)
+}
+
 func fileList(repo, rev string) ([]string, error) {
 	out, err := jjRun(repo, "file", "list", "-r", rev)
 	if err != nil {