From f558fbce5d3157f9c88240c185a74c6ba3a3e56f Mon Sep 17 00:00:00 2001
From: Sebastian Sebbie Silbermann <sebastian.silbermann@vercel.com>
Date: Mon, 9 Feb 2026 23:56:45 +0100
Subject: [PATCH 1/2] Current behavior

---
 .../src/__tests__/store-test.js               | 97 +++++++++++++++++++
 1 file changed, 97 insertions(+)

diff --git a/packages/react-devtools-shared/src/__tests__/store-test.js b/packages/react-devtools-shared/src/__tests__/store-test.js
index f3bcf189c8ca..0138ab8be785 100644
--- a/packages/react-devtools-shared/src/__tests__/store-test.js
+++ b/packages/react-devtools-shared/src/__tests__/store-test.js
@@ -3617,6 +3617,103 @@ describe('Store', () => {
     `);
   });
 
+  // @reactVersion >= 17.0
+  it('continues to consider Suspense boundary as blocking if some child still is suspended on removed io', async () => {
+    function Component({promise}) {
+      readValue(promise);
+      return null;
+    }
+
+    let resolve;
+    const promise = new Promise(_resolve => {
+      resolve = _resolve;
+    });
+
+    await actAsync(() => {
+      render(
+        <React.Suspense fallback={null} name="outer">
+          <Component key="one" promise={promise} />
+          <Component key="two" promise={promise} />
+          <React.Suspense fallback={null} name="inner">
+            <Component key="three" promise={promise} />
+          </React.Suspense>
+        </React.Suspense>,
+      );
+    });
+
+    expect(store).toMatchInlineSnapshot(`
+      [root]
+          <Suspense name="outer">
+      [suspense-root]  rects={null}
+        <Suspense name="outer" uniqueSuspenders={true} rects={null}>
+    `);
+
+    await actAsync(() => {
+      resolve('Hello, World!');
+    });
+
+    expect(store).toMatchInlineSnapshot(`
+      [root]
+        ▾ <Suspense name="outer">
+            <Component key="one">
+            <Component key="two">
+          ▾ <Suspense name="inner">
+              <Component key="three">
+      [suspense-root]  rects={null}
+        <Suspense name="outer" uniqueSuspenders={true} rects={null}>
+          <Suspense name="inner" uniqueSuspenders={false} rects={null}>
+    `);
+
+    // We remove one suspender.
+    // The inner one shouldn't have unique suspenders because it's still blocked
+    // by the outer one.
+    await actAsync(() => {
+      render(
+        <React.Suspense fallback={null} name="outer">
+          <Component key="one" promise={promise} />
+          <React.Suspense fallback={null} name="inner">
+            <Component key="three" promise={promise} />
+          </React.Suspense>
+        </React.Suspense>,
+      );
+    });
+
+    expect(store).toMatchInlineSnapshot(`
+      [root]
+        ▾ <Suspense name="outer">
+            <Component key="one">
+          ▾ <Suspense name="inner">
+              <Component key="three">
+      [suspense-root]  rects={null}
+        <Suspense name="outer" uniqueSuspenders={true} rects={null}>
+          <Suspense name="inner" uniqueSuspenders={true} rects={null}>
+    `);
+
+    // Now we remove all unique suspenders of the outer Suspense boundary.
+    // The inner one is now independently revealed from the parent and should
+    // be marked as having unique suspenders.
+    // TODO: The outer boundary no longer has unique suspenders.
+    await actAsync(() => {
+      render(
+        <React.Suspense fallback={null} name="outer">
+          <React.Suspense fallback={null} name="inner">
+            <Component key="three" promise={promise} />
+          </React.Suspense>
+        </React.Suspense>,
+      );
+    });
+
+    expect(store).toMatchInlineSnapshot(`
+      [root]
+        ▾ <Suspense name="outer">
+          ▾ <Suspense name="inner">
+              <Component key="three">
+      [suspense-root]  rects={null}
+        <Suspense name="outer" uniqueSuspenders={true} rects={null}>
+          <Suspense name="inner" uniqueSuspenders={true} rects={null}>
+    `);
+  });
+
   // @reactVersion >= 19
   it('cleans up host hoistables', async () => {
     function Left() {

From 4cd0fb64f3f3e973e839fe75c052e6221748f1d6 Mon Sep 17 00:00:00 2001
From: Sebastian Sebbie Silbermann <sebastian.silbermann@vercel.com>
Date: Mon, 9 Feb 2026 23:58:36 +0100
Subject: [PATCH 2/2] [DevTools] Only block child Suspense boundaries if the
 parent has all shared suspenders removed

---
 .../src/__tests__/store-test.js               |  2 +-
 .../src/backend/fiber/renderer.js             | 19 ++++++++++---------
 2 files changed, 11 insertions(+), 10 deletions(-)

diff --git a/packages/react-devtools-shared/src/__tests__/store-test.js b/packages/react-devtools-shared/src/__tests__/store-test.js
index 0138ab8be785..36198ac1e079 100644
--- a/packages/react-devtools-shared/src/__tests__/store-test.js
+++ b/packages/react-devtools-shared/src/__tests__/store-test.js
@@ -3686,7 +3686,7 @@ describe('Store', () => {
               <Component key="three">
       [suspense-root]  rects={null}
         <Suspense name="outer" uniqueSuspenders={true} rects={null}>
-          <Suspense name="inner" uniqueSuspenders={true} rects={null}>
+          <Suspense name="inner" uniqueSuspenders={false} rects={null}>
     `);
 
     // Now we remove all unique suspenders of the outer Suspense boundary.
diff --git a/packages/react-devtools-shared/src/backend/fiber/renderer.js b/packages/react-devtools-shared/src/backend/fiber/renderer.js
index 916d69823285..905524d0dd1b 100644
--- a/packages/react-devtools-shared/src/backend/fiber/renderer.js
+++ b/packages/react-devtools-shared/src/backend/fiber/renderer.js
@@ -3197,15 +3197,16 @@ export function attach(
                 environmentCounts.set(env, count - 1);
               }
             }
-          }
-          if (
-            suspenseNode.hasUniqueSuspenders &&
-            !ioExistsInSuspenseAncestor(suspenseNode, ioInfo)
-          ) {
-            // This entry wasn't in any ancestor and is no longer in this suspense boundary.
-            // This means that a child might now be the unique suspender for this IO.
-            // Search the child boundaries to see if we can reveal any of them.
-            unblockSuspendedBy(suspenseNode, ioInfo);
+
+            if (
+              suspenseNode.hasUniqueSuspenders &&
+              !ioExistsInSuspenseAncestor(suspenseNode, ioInfo)
+            ) {
+              // This entry wasn't in any ancestor and is no longer in this suspense boundary.
+              // This means that a child might now be the unique suspender for this IO.
+              // Search the child boundaries to see if we can reveal any of them.
+              unblockSuspendedBy(suspenseNode, ioInfo);
+            }
           }
         }
       }