report the EE gate instead of a 500 on restart flow at step (#10846)

Claude-Session: https://claude.ai/code/session_01CbayDTXcGCTYuE9m56BRag

Co-authored-by: Claude Opus 5 (1M context) <noreply@anthropic.com>

backend/windmill-api-integration-tests/tests/jobs_authed.rs

@@ -286,13 +286,24 @@ async fn test_jobs_authed_reachability(db: Pool<Postgres>) -> anyhow::Result<()>
         "GET /jobs/result_by_id",
     );
 
+    // Sent the way the generated client sends it. A handler whose `Path` tuple has drifted from
+    // the route is rejected by axum before it runs, which surfaces as a routing error rather
+    // than the handler's own answer, so reaching the handler is what this pins.
     let resp = authed(client().post(format!("{base}/restart/f/{fake}")))
+        .json(&json!({ "step_id": "a" }))
         .send()
         .await?;
-    assert_route_reachable(
-        resp.status().as_u16(),
-        &resp.text().await?,
-        "POST /jobs/restart/f",
+    let status = resp.status().as_u16();
+    let body = resp.text().await?;
+    assert_route_reachable(status, &body, "POST /jobs/restart/f");
+    assert!(
+        !body.contains("path arguments"),
+        "POST /jobs/restart/f never reached its handler: {status} {body}",
+    );
+    #[cfg(not(feature = "enterprise"))]
+    assert!(
+        body.contains("only available in enterprise version"),
+        "POST /jobs/restart/f must report the enterprise gate outside EE: {status} {body}",
     );
 
     let resp = authed(client().post(format!("{base}/run/workflow_as_code/{fake}/main")))

backend/windmill-api/src/jobs.rs

@@ -6559,17 +6559,18 @@ pub async fn run_flow_by_version_inner(
     Ok((uuid, early_return, has_failure_module))
 }
 
+/// Path parameters of `POST /w/{workspace}/jobs/restart/f/{job_id}`, shared by the CE and EE
+/// handlers. Axum only checks the tuple against the route at request time and rejects a
+/// mismatch with an opaque 500 before the handler runs, so both must be declared from here:
+/// an arity that drifts from the route hides the handler behind what reads as a broken route.
+type RestartFlowPath = Path<(String, Uuid)>;
+
 #[cfg(not(feature = "enterprise"))]
 pub async fn restart_flow(
     _authed: ApiAuthed,
     Extension(_db): Extension<DB>,
     Extension(_user_db): Extension<UserDB>,
-    Path((_w_id, _job_id, _step_id, _branch_or_iteration_n)): Path<(
-        String,
-        Uuid,
-        String,
-        Option<usize>,
-    )>,
+    Path((_w_id, _job_id)): RestartFlowPath,
     Query(_run_query): Query<RunJobQuery>,
 ) -> error::Result<(StatusCode, String)> {
     return Err(Error::BadRequest(
@@ -6798,7 +6799,7 @@ pub async fn restart_flow(
     authed: ApiAuthed,
     Extension(db): Extension<DB>,
     Extension(user_db): Extension<UserDB>,
-    Path((w_id, job_id)): Path<(String, Uuid)>,
+    Path((w_id, job_id)): RestartFlowPath,
     Query(run_query): Query<RunJobQuery>,
     Json(RestartFlowRequestBody {
         step_id,