fix: space remounted slot, close #6500

Author: tangjinzhou

components/space/index.tsx

@@ -1,5 +1,5 @@
 import type { PropType, ExtractPropTypes, CSSProperties } from 'vue';
-import { defineComponent, computed, ref, watch } from 'vue';
+import { defineComponent, computed, ref, watch, Fragment } from 'vue';
 import PropTypes from '../_util/vue-types';
 import { filterEmpty } from '../_util/props-util';
 import type { SizeType } from '../config-provider';
@@ -80,8 +80,8 @@ const Space = defineComponent({
     });
     return () => {
       const { wrap, direction = 'horizontal' } = props;
-
-      const items = filterEmpty(slots.default?.());
+      const children = slots.default?.();
+      const items = filterEmpty(children);
       const len = items.length;
 
       if (len === 0) {
@@ -94,6 +94,7 @@ const Space = defineComponent({
       return (
         <div class={cn.value} style={style.value}>
           {items.map((child, index) => {
+            const originIndex = children.indexOf(child);
             let itemStyle: CSSProperties = {};
             if (!supportFlexGap.value) {
               if (direction === 'vertical') {
@@ -111,7 +112,7 @@ const Space = defineComponent({
             }
 
             return (
-              <>
+              <Fragment key={originIndex}>
                 <div class={itemClassName} style={itemStyle}>
                   {child}
                 </div>
@@ -120,7 +121,7 @@ const Space = defineComponent({
                     {split}
                   </span>
                 )}
-              </>
+              </Fragment>
             );
           })}
         </div>