diff --git a/rust/hg-core/src/revset.rs b/rust/hg-core/src/revset.rs
--- a/rust/hg-core/src/revset.rs
+++ b/rust/hg-core/src/revset.rs
@@ -19,21 +19,19 @@
 ) -> Result<Revision, RevlogError> {
     let changelog = Changelog::open(repo)?;
 
-    match resolve_rev_number_or_hex_prefix(input, &changelog.revlog) {
-        Err(RevlogError::InvalidRevision) => {} // Try other syntax
-        result => return result,
-    }
-
-    if input == "null" {
-        return Ok(NULL_REVISION);
+    match input {
+        "null" => return Ok(NULL_REVISION),
+        _ => {
+            match resolve_rev_number_or_hex_prefix(input, &changelog.revlog) {
+                Err(RevlogError::InvalidRevision) => {
+                    // TODO: support for the rest of the language here.
+                    let msg = format!("cannot parse revset '{}'", input);
+                    Err(HgError::unsupported(msg).into())
+                }
+                result => return result,
+            }
+        }
     }
-
-    // TODO: support for the rest of the language here.
-
-    Err(
-        HgError::unsupported(format!("cannot parse revset '{}'", input))
-            .into(),
-    )
 }
 
 /// Resolve the small subset of the language suitable for revlogs other than