fix: preserve pending range selection on hover

src/PickerInput/Popup/PopupPanel.tsx

@@ -30,6 +30,7 @@ export default function PopupPanel<DateType extends object = any>(
     onSubmit,
     range,
     hoverValue,
+    hoverRangeValue,
   } = props;
   const { prefixCls, generateConfig } = React.useContext(PickerContext);
 
@@ -70,10 +71,9 @@ export default function PopupPanel<DateType extends object = any>(
     hideHeader,
   };
 
+  pickerProps.hoverValue = hoverValue;
   if (range) {
-    pickerProps.hoverRangeValue = hoverValue;
-  } else {
-    pickerProps.hoverValue = hoverValue;
+    pickerProps.hoverRangeValue = hoverRangeValue;
   }
 
   // ======================== Render ========================

src/PickerInput/RangePicker.tsx

@@ -24,6 +24,7 @@ import type {
 import type { PickerPanelProps } from '../PickerPanel';
 import PickerTrigger from '../PickerTrigger';
 import { pickTriggerProps } from '../PickerTrigger/util';
+import { isSameTimestamp } from '../utils/dateUtil';
 import { fillIndex, getFromDate, toArray } from '../utils/miscUtil';
 import PickerContext from './context';
 import useCellRender from './hooks/useCellRender';
@@ -502,6 +503,17 @@ function RangePicker<DateType extends object = any>(
     return internalHoverValues || calendarValue;
   }, [calendarValue, internalHoverValues]);
 
+  // "Weak" hover only highlights the hovered cell instead of composing a range.
+  // Use it while choosing the first value so the pending selection remains selected.
+  const showWeakHover =
+    // Preset hover always previews the whole range.
+    hoverSource === 'cell' &&
+    // Once the other field has a value, range hover takes precedence.
+    !calendarValue[(activeIndex + 1) % 2] &&
+    // Only a changed active value needs weak hover.
+    !isSameTimestamp(generateConfig, calendarValue[activeIndex], mergedValue[activeIndex]);
+  const activeHoverValue = internalHoverValues?.[activeIndex];
+
   // Clean up `internalHoverValues` when closed
   React.useEffect(() => {
     if (!mergedOpen) {
@@ -640,7 +652,8 @@ function RangePicker<DateType extends object = any>(
       defaultOpenValue={toArray(showTime?.defaultOpenValue)[activeIndex]}
       onPickerValueChange={setCurrentPickerValue}
       // Hover
-      hoverValue={hoverValues}
+      hoverValue={showWeakHover && activeHoverValue ? [activeHoverValue] : null}
+      hoverRangeValue={showWeakHover ? null : hoverValues}
       onHover={onPanelHover}
       // Submit
       needConfirm={needConfirm}

tests/range.spec.tsx

@@ -768,6 +768,41 @@ describe('Picker.Range', () => {
         expect(findCell(end)).not.toHaveClass('rc-picker-cell-range-end');
       });
     });
+
+    it.each([true, false])(
+      'should keep the pending selection when hovering with needConfirm=%s',
+      async (needConfirm) => {
+        const { container } = render(<DayRangePicker showTime needConfirm={needConfirm} />);
+        openPicker(container);
+        selectCell(11);
+
+        expect(findCell(11)).toHaveClass('rc-picker-cell-range-start');
+
+        fireEvent.mouseEnter(findCell(22));
+        await waitFakeTimer();
+
+        expect(container.querySelectorAll('input')[0]).toHaveValue('1990-09-22 00:00:00');
+        expect(findCell(11)).toHaveClass('rc-picker-cell-selected');
+        expect(findCell(11)).not.toHaveClass('rc-picker-cell-range-start');
+        expect(findCell(22)).toHaveClass('rc-picker-cell-hover');
+        expect(findCell(22)).not.toHaveClass('rc-picker-cell-range-start');
+      },
+    );
+
+    it('should keep range hover after the first field is confirmed', async () => {
+      const { container } = render(<DayRangePicker showTime />);
+      openPicker(container);
+      selectCell(11);
+      fireEvent.click(document.querySelector('.rc-picker-ok button'));
+      selectCell(22);
+
+      fireEvent.mouseEnter(findCell(25));
+      await waitFakeTimer();
+
+      expect(findCell(11)).toHaveClass('rc-picker-cell-range-start');
+      expect(findCell(15)).toHaveClass('rc-picker-cell-in-range');
+      expect(findCell(25)).toHaveClass('rc-picker-cell-range-end');
+    });
   });
 
   it('should close when user focus out', () => {