DatePicker: fix select year in month type, fixed #1070

packages/date-picker/src/panel/date.vue

@@ -271,6 +271,7 @@
           this.resetDate();
         } else {
           this.date.setMonth(month);
+          this.year && this.date.setFullYear(this.year);
           this.resetDate();
           const value = new Date(this.date.getFullYear(), month, 1);
           this.$emit('pick', value);

packages/theme-default/src/date-picker/year-table.css

@@ -4,6 +4,7 @@
   @b year-table {
     font-size: 12px;
     margin: -1px;
+    border-collapse: collapse;
 
     .el-icon {
       color: var(--datepicker-icon-color);