From b93bf5600e4a4e38666a8ee81a8df32c57aa1610 Mon Sep 17 00:00:00 2001
From: Tobias Koppers <tobias.koppers@googlemail.com>
Date: Wed, 30 Apr 2025 15:40:38 +0200
Subject: [PATCH] Turbopack: avoid tracking a modification when adding an
 already existing item

---
 turbopack/crates/turbo-tasks-backend/src/backend/mod.rs      | 4 ++--
 .../crates/turbo-tasks-backend/src/backend/operation/mod.rs  | 5 ++++-
 2 files changed, 6 insertions(+), 3 deletions(-)

diff --git a/turbopack/crates/turbo-tasks-backend/src/backend/mod.rs b/turbopack/crates/turbo-tasks-backend/src/backend/mod.rs
index 4611fc407e0da..9fe9c758bed91 100644
--- a/turbopack/crates/turbo-tasks-backend/src/backend/mod.rs
+++ b/turbopack/crates/turbo-tasks-backend/src/backend/mod.rs
@@ -1501,7 +1501,7 @@ impl<B: BackingStorage> TurboTasksBackendInner<B> {
 
         // handle stateful
         if stateful {
-            task.insert(CachedDataItem::Stateful { value: () });
+            let _ = task.add(CachedDataItem::Stateful { value: () });
         }
 
         // handle cell counters: update max index and remove cells that are no longer used
@@ -1938,7 +1938,7 @@ impl<B: BackingStorage> TurboTasksBackendInner<B> {
                     .entry(RawVc::TaskCell(collectible.task, collectible.cell))
                     .or_insert(0) += count;
             }
-            task.insert(CachedDataItem::CollectiblesDependent {
+            let _ = task.add(CachedDataItem::CollectiblesDependent {
                 collectible_type,
                 task: reader_id,
                 value: (),
diff --git a/turbopack/crates/turbo-tasks-backend/src/backend/operation/mod.rs b/turbopack/crates/turbo-tasks-backend/src/backend/operation/mod.rs
index e1a43103929ac..7584731bcaaaa 100644
--- a/turbopack/crates/turbo-tasks-backend/src/backend/operation/mod.rs
+++ b/turbopack/crates/turbo-tasks-backend/src/backend/operation/mod.rs
@@ -14,7 +14,7 @@ use std::{
 };
 
 use serde::{Deserialize, Serialize};
-use turbo_tasks::{SessionId, TaskId, TurboTasksBackendApi};
+use turbo_tasks::{KeyValuePair, SessionId, TaskId, TurboTasksBackendApi};
 
 use crate::{
     backend::{
@@ -466,6 +466,9 @@ impl<B: BackingStorage> TaskGuard for TaskGuardImpl<'_, B> {
         let category = item.category();
         self.check_access(category);
         if !self.task_id.is_transient() && item.is_persistent() {
+            if self.task.contains_key(&item.key()) {
+                return false;
+            }
             self.task.track_modification(category.into_specific());
         }
         self.task.add(item)