Undoing import leads to wrong client state (#642)

teammapper-frontend/mmp/src/map/handlers/history.ts

@@ -98,6 +98,7 @@ export default class History {
                 }
                 Log.error('There was an error importing the map; changes have been rolled back.')
             } else {
+                this.clearHistory()
                 this.save()
                 if (notifyWithEvent) this.map.events.call(Event.create, this.map.dom, { previousMap: previousData })
             }
@@ -154,6 +155,14 @@ export default class History {
         this.index++
     }
 
+    /**
+     * Clears the history of the map
+     */
+    public clearHistory = () => {
+        this.snapshots = []
+        this.index = -1
+    }
+
     /**
      * Return all history of map with all snapshots.
      * @returns {MapSnapshot[]}

teammapper-frontend/src/app/modules/application/components/toolbar/toolbar.component.html

@@ -111,7 +111,7 @@
   <button
     (click)="mmpService.undo()"
     [title]="'TOOLTIPS.UNDO_MAP' | translate"
-    [disabled]="editDisabled"
+    [disabled]="editDisabled || !canUndoRedo"
     color="primary"
     mat-icon-button>
     <mat-icon>undo</mat-icon>
@@ -120,7 +120,7 @@
   <button
     (click)="mmpService.redo()"
     [title]="'TOOLTIPS.REDO_MAP' | translate"
-    [disabled]="editDisabled"
+    [disabled]="editDisabled || !canUndoRedo"
     color="primary"
     mat-icon-button>
     <mat-icon>redo</mat-icon>

teammapper-frontend/src/app/modules/application/components/toolbar/toolbar.component.ts

@@ -43,6 +43,14 @@ export class ToolbarComponent {
     }
   }
 
+  get canUndoRedo() {
+    if (this.mmpService && typeof this.mmpService.history === 'function') {
+      const history = this.mmpService.history();
+      return history?.snapshots?.length > 1;
+    }
+    return false;
+  }
+
   public async share() {
     this.dialogService.openShareDialog();
   }