Record background print hooks as one command

crates/engine/src/jobs.rs

@@ -751,18 +751,25 @@ impl Session {
         };
         self.coalesce_request = coalesce.clone();
         self.color_restrict = *color_restrict;
+        // Apply-time hooks can dispatch commands too. Keep the same single-step recording
+        // contract as synchronous dispatch without truncating work done while the worker ran.
+        let nested_from = self.journal.len();
+        let recording = if *journal && crate::actions_cmds::replayable(command) { self.actions.recording.take() } else { None };
         let r = match apply {
             Some(f) => std::panic::catch_unwind(std::panic::AssertUnwindSafe(|| f(self, payload)))
                 .unwrap_or_else(|_| Err(EngineError::Other(format!("`{label}` failed with an internal error (logged); the document is unchanged")))),
             None => Err(EngineError::Other("internal error: job applied twice".into())),
         };
+        if self.actions.recording.is_none() {
+            self.actions.recording = recording;
+        }
         self.coalesce_request = None;
         self.color_restrict = None;
         // Finish successful command bookkeeping on the document the job edited.
         // Restoring the viewed document first would attribute Fade and slice updates
         // to that document instead, when the user switched tabs mid-job.
         if r.is_ok() {
-            self.after_command(command, params.clone(), *journal, None);
+            self.after_command(command, params.clone(), *journal, Some(nested_from));
         }
         // Keep the user's active document unless the job opened a new one.
         // This also restores the selection when the apply step returned an error.

crates/engine/src/print_cmds/tests.rs

@@ -254,7 +254,10 @@ fn spool_transport_streams_pdf_and_propagates_refusal() {
         assert!(s.execute("jobs.cancel", json!({"job": job.0})).unwrap_err().to_string().contains("system print queue"));
         s.execute("file.new", json!({"width": 40, "height": 10})).unwrap();
         let viewed = s.active().unwrap().doc.id;
+        let journal_before_completion = s.journal.len();
         let out = s.wait_job(job).unwrap();
+        assert_eq!(s.journal.len(), journal_before_completion + 1, "print hooks must not become duplicate recorded action steps");
+        assert_eq!(s.journal.last().unwrap().0, "file.print");
         assert_eq!(s.active().unwrap().doc.id, viewed, "completion keeps the user's tab");
         assert_eq!(s.active().unwrap().doc.size.width, 40, "print hook must not act on the newly viewed document");
         let printed = &s.documents().iter().find(|st| st.doc.id == source).unwrap().doc;