Show badge only if there are comments

src/app/components/shared/room-list/room-list.component.html

@@ -14,8 +14,8 @@
 
     <!-- filter input -->
     <mat-form-field *ngIf="this.rooms && this.rooms.length > 5" class="filterWrapper">
-      <input (focus)="eventService.makeFocusOnInputTrue()" (blur)="eventService.makeFocusOnInputFalse()" matInput (keyup)="applyFilter($event.target.value)"
-             class="filter"
+      <input (focus)="eventService.makeFocusOnInputTrue()" (blur)="eventService.makeFocusOnInputFalse()" matInput
+             (keyup)="applyFilter($event.target.value)" class="filter"
              attr.aria-labelledby="sessionHistoryLabel{{ this.rooms.length === 1 ? '1' : '' }}"/>
       <mat-placeholder class="placeholder">{{ 'room-list.filter-message' | translate }}</mat-placeholder>
     </mat-form-field>
@@ -29,7 +29,9 @@
             {{ 'room-list.panel-session-name' | translate }}
           </th>
           <td mat-cell *matCellDef="let room">
-            <span matBadge="{{room.commentCount}}" matBadgeOverlap="false">{{ room.name }}</span>
+            <span matBadge="{{room.commentCount > 0 ? room.commentCount : null}}" matBadgeOverlap="false">
+              {{ room.name }}
+            </span>
           </td>
         </ng-container>