Select: Fix issue (#22303)

Test: Update select 'filterable' test case

packages/select/src/option.vue

@@ -138,6 +138,8 @@
         this.visible = new RegExp(escapeRegexpString(query), 'i').test(this.currentLabel) || this.created;
         if (!this.visible) {
           this.select.filteredOptionsCount--;
+        } else if (query === '') {
+          this.select.filteredOptionsCount = this.select.optionsCount;
         }
       }
     },

test/unit/specs/select.spec.js

@@ -450,9 +450,11 @@ describe('Select', () => {
     vm = getSelectVm({ filterable: true });
     const select = vm.$children[0];
     setTimeout(() => {
+      select.visible = true;
+      select.$nextTick(() => {
         select.selectedLabel = '面';
         select.onInputChange();
-      select.visible = true;
+      });
       setTimeout(() => {
         expect(select.filteredOptionsCount).to.equal(1);
         done();