Address code review feedback: improve variable naming and add comment

Co-authored-by: meet-student <59312002+meet-student@users.noreply.github.com>

components/typography/Base/util.ts

@@ -21,6 +21,12 @@ export function getNode(dom: React.ReactNode, defaultNode: React.ReactNode, need
 export function isEleEllipsis(ele: HTMLElement): boolean {
   // Create a new div to get the size
   const childDiv = document.createElement('em');
+  
+  // Set styles to prevent the child element from affecting layout measurements
+  // line-height: 0 prevents font metrics from causing false positives
+  childDiv.style.lineHeight = '0';
+  childDiv.style.verticalAlign = 'top';
+  
   ele.appendChild(childDiv);
 
   // For test case

components/typography/__tests__/ellipsis.test.tsx

@@ -387,10 +387,16 @@ describe('Typography.Ellipsis', () => {
               'ant-typography-css-ellipsis-content-measure',
             )
           ) {
+            // Check if line-height is set to 0 (from the fix)
+            const element = this as unknown as HTMLElement;
+            const lineHeight = element.style.lineHeight;
+            // 22 is the default LINE_HEIGHT used in the test setup
+            const height = lineHeight === '0' ? 0 : 22;
+            
             return {
               ...measureRect,
               right: measureRect.left,
-              bottom: measureRect.top + 22,
+              bottom: measureRect.top + height,
             };
           }
 
@@ -502,6 +508,29 @@ describe('Typography.Ellipsis', () => {
 
         expect(baseElement.querySelector('.ant-tooltip-open')).toBeFalsy();
       });
+
+      // Fix for font metric issue where em element height differs from container
+      it('should not show tooltip when em height differs due to font metrics', async () => {
+        // Simulate scenario where:
+        // - Container and measure have same horizontal bounds (no horizontal overflow)
+        // - Without fix: em element height would be 20px, container is 18px
+        // - With fix: em element height is 0px (line-height: 0)
+        containerRect.right = 100;
+        containerRect.bottom = 18;
+        measureRect.left = 0;
+        measureRect.top = 0;
+
+        const { container, baseElement } = await getWrapper({
+          title: true,
+        });
+        fireEvent.mouseEnter(container.firstChild!);
+
+        await waitFakeTimer();
+
+        // With the fix, tooltip should not show because text is not actually ellipsed
+        // The em element now has line-height: 0, so its height won't exceed container height
+        expect(baseElement.querySelector('.ant-tooltip-open')).toBeFalsy();
+      });
     });
   });