Fix potential issue with toggling setting mid-permission check (2)

Author: jpenilla

cloud-core/src/main/java/org/incendo/cloud/CommandManager.java

@@ -413,7 +413,11 @@ public boolean hasCapability(final @NonNull CloudCapability capability) {
         final boolean cache = this.settings.get(ManagerSetting.REDUCE_REDUNDANT_PERMISSION_CHECKS);
         try {
             if (cache) {
-                this.threadLocalPermissionCache.get().second().incrementAndGet();
+                final int prev = this.threadLocalPermissionCache.get().second().incrementAndGet();
+                if (prev == 0) {
+                    // Cleanup from case where cache was enabled mid-permission check
+                    this.threadLocalPermissionCache.get().first().clear();
+                }
             }
             return this.testPermission_(sender, permission);
         } finally {