message: [bugfix] Progress: text empty
diff: <template>
  <div :class="b()">
  - <span :class="b('portion', { 'with-pivot': showPivot })" :style="portionStyle">
  - <span v-if="showPivot" ref="pivot" :style="pivotStyle" :class="b('pivot')">{{ pivotText }}</span>
  + <span :class="b('portion', { 'with-pivot': showPivot && text })" :style="portionStyle">
  + <span v-if="showPivot && text" ref="pivot" :style="pivotStyle" :class="b('pivot')">{{ text }}</span>
  </span>
  </div>
  </template>
  @@ -14,6 +14,7 @@ export default create({
  props: {
  inactive: Boolean,
  + pivotText: String,
  pivotColor: String,
  percentage: {
  type: Number,
  @@ -24,12 +25,6 @@ export default create({
  type: Boolean,
  default: true
  },
  - pivotText: {
  - type: String,
  - default() {
  - return this.percentage + '%';
  - }
  - },
  color: {
  type: String,
  default: '#38f'
  @@ -48,6 +43,12 @@ export default create({
  },
  computed: {
  + text() {
  + return this.isDef(this.pivotText)
  + ? this.pivotText
  + : this.percentage + '%';
  + },
  +
  currentColor() {
  return this.inactive ? '#cacaca' : this.color;
  },
  