JDK-8306055 introduced `XMLSecurityManager#prepareCatalog`, which is called in the constructor, to initialize the built-in `JdkCatalog` via `JdkCatalog#init`.

There is synchronization in `prepareCatalog`, but it seems to be problematic. First, the `lock` object is non-static. Since the method is called only once in the constructor, this look seems non-functional. Second, `jdkcatalogInitialized` is set to `true` before the catalog is actually initialized. Thus, a second thread calling `prepareCatalog` might see it as true although `JdkCatalog` is not initialized.

I believe the following code would fix the issues:
```
    static volatile boolean jdkcatalogInitialized = false;
    private static final Object lock = new Object();

    private void prepareCatalog() {
        if (!jdkcatalogInitialized) {
            synchronized (lock) {
                if (!jdkcatalogInitialized) {
                    String resolve = getLimitValueAsString(Limit.JDKCATALOG_RESOLVE);
                    JdkCatalog.init(resolve);
                    jdkcatalogInitialized = true;
                }
            }
        }
    }
```