CodeActionSet should not mutate input array

src/vs/editor/contrib/codeAction/codeAction.ts

@@ -34,8 +34,8 @@ export class CodeActionSet {
 
 	public readonly actions: readonly CodeAction[];
 
-	public constructor(actions: CodeAction[]) {
-		this.actions = mergeSort(actions, CodeActionSet.codeActionsComparator);
+	public constructor(actions: readonly CodeAction[]) {
+		this.actions = mergeSort(Array.from(actions), CodeActionSet.codeActionsComparator);
 	}
 
 	public get hasAutoFix() {