Retain prompt resume resize until route transition

crates/lazaret-host-coordinator/src/terminal.rs

@@ -188,12 +188,14 @@ struct PendingPrompt {
     authority: VerifiedSession,
     prompt: TerminalPrompt,
     emitted: bool,
+    resumed_size: Option<TerminalResize>,
 }
 
 #[derive(Clone, Debug, Eq, PartialEq)]
 pub struct RoutedPromptDecision {
     pub signed_decision: Vec<u8>,
     pub decision: DeveloperDecision,
+    pub resumed_size: Option<TerminalResize>,
 }
 
 pub struct SessionPromptTransport {
@@ -264,6 +266,7 @@ impl SessionPromptTransport {
                 authority,
                 prompt: prompt.clone(),
                 emitted: false,
+                resumed_size: None,
             },
         );
         Ok(prompt)
@@ -288,7 +291,7 @@ impl SessionPromptTransport {
         &self,
         session_id: SessionId,
         signed_decision: Vec<u8>,
-    ) -> Result<DeveloperDecision, TerminalError> {
+    ) -> Result<RoutedPromptDecision, TerminalError> {
         let mut prompts = self
             .pending
             .lock()
@@ -304,19 +307,40 @@ impl SessionPromptTransport {
                 pending.prompt.request_sha256,
             )
             .map_err(|_| TerminalError::PromptValidation)?;
+        let resumed_size = pending.resumed_size;
         prompts.remove(&session_id);
-        drop(prompts);
+        Ok(RoutedPromptDecision {
+            signed_decision,
+            decision,
+            resumed_size,
+        })
+    }
+
+    fn retain_prompt_resize(&self, resize: TerminalResize) -> Result<bool, TerminalError> {
+        let mut prompts = self
+            .pending
+            .lock()
+            .map_err(|_| TerminalError::PromptValidation)?;
+        let Some(pending) = prompts.get_mut(&resize.session_id) else {
+            return Ok(false);
+        };
+        if !pending.emitted {
+            return Err(TerminalError::InactiveRoute);
+        }
+        pending.resumed_size = Some(resize);
+        Ok(true)
+    }
+
+    fn publish_decision(
+        &self,
+        session_id: SessionId,
+        decision: RoutedPromptDecision,
+    ) -> Result<(), TerminalError> {
         self.routed
             .lock()
             .map_err(|_| TerminalError::PromptValidation)?
-            .insert(
+            .insert(session_id, decision);
-                session_id,
+        Ok(())
-                RoutedPromptDecision {
-                    signed_decision,
-                    decision: decision.clone(),
-                },
-            );
-        Ok(decision)
     }
 
     fn restore_sandbox_route(&self, session_id: SessionId) -> Result<(), TerminalError> {
@@ -719,6 +743,19 @@ impl InteractiveControlSession for RunscInteractiveControlSession {
     ) -> Result<InteractiveSessionBatch, ControlError> {
         let mut engine = self.engine.lock().map_err(|_| ControlError::LockPoisoned)?;
         let mut messages = match event {
+            InteractiveSessionEvent::Terminal(SessionTerminalEvent::Resize(resize)) => {
+                if self
+                    .prompt_transport
+                    .retain_prompt_resize(resize)
+                    .map_err(|error| terminal_control_error(&error))?
+                {
+                    Vec::new()
+                } else {
+                    engine
+                        .handle(self.generation_id, SessionTerminalEvent::Resize(resize))
+                        .map_err(|error| terminal_control_error(&error))?
+                }
+            }
             InteractiveSessionEvent::Terminal(event) => engine
                 .handle(self.generation_id, event)
                 .map_err(|error| terminal_control_error(&error))?,
@@ -733,14 +770,23 @@ impl InteractiveControlSession for RunscInteractiveControlSession {
                     .prompt_transport
                     .route_decision(session_id, signed_decision)
                     .map_err(|error| terminal_control_error(&error))?;
-                if decision.decision == lazaret_core::records::DeveloperDecisionKind::Deny {
+                if decision.decision.decision == lazaret_core::records::DeveloperDecisionKind::Deny
+                {
                     self.prompt_transport
                         .restore_sandbox_route(session_id)
                         .map_err(|error| terminal_control_error(&error))?;
                     engine
                         .set_route(session_id, self.generation_id, TerminalRoute::Sandbox)
                         .map_err(|error| terminal_control_error(&error))?;
+                    if let Some(resize) = decision.resumed_size {
+                        engine
+                            .handle(self.generation_id, SessionTerminalEvent::Resize(resize))
+                            .map_err(|error| terminal_control_error(&error))?;
                     }
+                }
+                self.prompt_transport
+                    .publish_decision(session_id, decision)
+                    .map_err(|error| terminal_control_error(&error))?;
                 Vec::new()
             }
             InteractiveSessionEvent::PromptDecision { .. }

crates/lazaret-host-coordinator/src/terminal/tests.rs

@@ -539,7 +539,7 @@ fn engine_for(fixture: &Fixture) -> (Arc<MockFactory>, SessionTerminalEngine) {
 
 #[test]
 #[allow(clippy::too_many_lines)]
-fn production_prompt_adapter_routes_exact_authenticated_denial() {
+fn production_prompt_adapter_retains_resume_resize_before_authenticated_denial() {
     let generation = GenerationIdentity {
         agent_profile: "trusted".into(),
         domain_id: DomainId::new(bytes(1)),
@@ -607,7 +607,7 @@ fn production_prompt_adapter_routes_exact_authenticated_denial() {
     let factory = Arc::new(MockFactory::default());
     let mut engine = SessionTerminalEngine::new(
         Arc::clone(&fixture.store),
-        factory,
+        factory.clone(),
         prompt_transport.clone(),
     );
     engine.acquire(&acquisition(binding.session_id)).unwrap();
@@ -640,6 +640,18 @@ fn production_prompt_adapter_routes_exact_authenticated_denial() {
         batch.messages,
         vec![InteractiveSessionMessage::Prompt(expected_prompt.clone())]
     );
+    let resumed_size = TerminalResize {
+        session_id: binding.session_id,
+        rows: NonZeroU16::new(55).unwrap(),
+        columns: NonZeroU16::new(144).unwrap(),
+        pixel_width: 1_440,
+        pixel_height: 900,
+    };
+    control
+        .exchange(InteractiveSessionEvent::Terminal(
+            SessionTerminalEvent::Resize(resumed_size),
+        ))
+        .unwrap();
     let signed_decision = encode_signed(
         &DeveloperDecision {
             protocol_version: ProtocolVersion::V1,
@@ -664,6 +676,19 @@ fn production_prompt_adapter_routes_exact_authenticated_denial() {
         .unwrap();
     assert_eq!(routed.signed_decision, signed_decision);
     assert_eq!(routed.decision.decision, DeveloperDecisionKind::Deny);
+    assert_eq!(routed.resumed_size, Some(resumed_size));
+    assert_eq!(
+        factory.log.lock().unwrap().as_slice(),
+        ["resize:55x144", "signal:WINCH"]
+    );
+    assert!(
+        !factory
+            .log
+            .lock()
+            .unwrap()
+            .iter()
+            .any(|event| event == "signal:TSTP")
+    );
     assert_eq!(
         fixture
             .store