From 51d8e133a71acdf45a15da90c4f6331ac9bdd276 Mon Sep 17 00:00:00 2001
From: Georgi Stoyanov <georgi@gstellar.com>
Date: Tue, 22 Sep 2026 08:19:27 +0300
Subject: [PATCH 1/2] perf: optimize display value label lookup

---
 src/TreeSelect.tsx              | 11 ++++++++++-
 tests/Select.checkable.spec.tsx | 24 ++++++++++++++++++++++++
 2 files changed, 34 insertions(+), 1 deletion(-)

diff --git a/src/TreeSelect.tsx b/src/TreeSelect.tsx
index 75d88f8c..f2fbab58 100644
--- a/src/TreeSelect.tsx
+++ b/src/TreeSelect.tsx
@@ -412,9 +412,18 @@ const TreeSelect = React.forwardRef<BaseSelectRef, TreeSelectProps>((props, ref)
     // Convert to value and filled with label
     const values = displayKeys.map(key => keyEntities[key]?.node?.[mergedFieldNames.value] ?? key);
 
+    // Avoid an O(displayed values × selected values) lookup
+    const labeledValueMap = new Map<SafeKey, LabeledValueType>();
+    rawLabeledValues.forEach(item => {
+      // Match `find` by keeping the first entry when controlled values contain duplicates.
+      if (!labeledValueMap.has(item.value)) {
+        labeledValueMap.set(item.value, item);
+      }
+    });
+
     // Back fill with origin label
     const labeledValues = values.map(val => {
-      const targetItem = rawLabeledValues.find(item => item.value === val);
+      const targetItem = labeledValueMap.get(val);
       const label = labelInValue ? targetItem?.label : treeTitleRender?.(targetItem);
       return {
         value: val,
diff --git a/tests/Select.checkable.spec.tsx b/tests/Select.checkable.spec.tsx
index 646c608d..f30cbb88 100644
--- a/tests/Select.checkable.spec.tsx
+++ b/tests/Select.checkable.spec.tsx
@@ -531,6 +531,30 @@ describe('TreeSelect.checkable', () => {
       expect(getSelectionText(container, 0)).toEqual('0-0');
     });
 
+    it('preserves labels with SHOW_ALL', () => {
+      const { container } = render(
+        <TreeSelect
+          treeCheckable
+          showCheckedStrategy={SHOW_ALL}
+          labelInValue
+          value={[
+            { value: 'parent', label: 'Custom parent' },
+            { value: 'child', label: 'Custom child' },
+          ]}
+        >
+          <TreeNode key="parent" value="parent" title="Parent">
+            <TreeNode key="child" value="child" title="Child" />
+          </TreeNode>
+        </TreeSelect>,
+      );
+
+      expect(getSelections(container)).toHaveLength(2);
+      expect([getSelectionText(container, 0), getSelectionText(container, 1)]).toEqual([
+        'Custom parent',
+        'Custom child',
+      ]);
+    });
+
     // https://github.com/ant-design/ant-design/issues/38126
     it('keep label when not in options', () => {
       const onChange = jest.fn();

From 7e770c54d8341dd2a192ae0e1d1d68988992644b Mon Sep 17 00:00:00 2001
From: Georgi Stoyanov <georgi@gstellar.com>
Date: Tue, 22 Sep 2026 09:50:21 +0300
Subject: [PATCH 2/2] test: update test to cover duplicate values

---
 tests/Select.checkable.spec.tsx | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/tests/Select.checkable.spec.tsx b/tests/Select.checkable.spec.tsx
index f30cbb88..685d18f4 100644
--- a/tests/Select.checkable.spec.tsx
+++ b/tests/Select.checkable.spec.tsx
@@ -538,7 +538,8 @@ describe('TreeSelect.checkable', () => {
           showCheckedStrategy={SHOW_ALL}
           labelInValue
           value={[
-            { value: 'parent', label: 'Custom parent' },
+            { value: 'parent', label: 'First parent label' },
+            { value: 'parent', label: 'Second parent label' },
             { value: 'child', label: 'Custom child' },
           ]}
         >
@@ -550,7 +551,7 @@ describe('TreeSelect.checkable', () => {
 
       expect(getSelections(container)).toHaveLength(2);
       expect([getSelectionText(container, 0), getSelectionText(container, 1)]).toEqual([
-        'Custom parent',
+        'First parent label',
         'Custom child',
       ]);
     });