Progress can go backwards (fixes #46717)

src/vs/workbench/api/node/extHostProgress.ts

@@ -72,8 +72,8 @@ function mergeProgress(result: IProgressStep, currentValue: IProgressStep): IPro
 	result.message = currentValue.message;
 	if (typeof currentValue.percentage === 'number' && typeof result.message === 'number') {
 		result.percentage += currentValue.percentage;
-	} else {
-		result.percentage = currentValue.percentage || result.percentage;
+	} else if (typeof currentValue.percentage === 'number') {
+		result.percentage = currentValue.percentage;
 	}
 	return result;
 }

src/vs/workbench/browser/parts/notifications/notificationsViewer.ts

@@ -469,7 +469,7 @@ export class NotificationTemplateRenderer {
 
 		// Total / Worked
 		else if (typeof state.total === 'number' || typeof state.worked === 'number') {
-			if (typeof state.total === 'number') {
+			if (typeof state.total === 'number' && !this.template.progress.hasTotal()) {
 				this.template.progress.total(state.total);
 			}