HTTPCLIENT-2379 - Return early when an entry’s lease count is zero, avoiding a second call to the

delegate pool and its resulting IllegalStateException.

Author: arturobernalg

httpclient5/src/main/java/org/apache/hc/client5/http/impl/nio/H2SharingConnPool.java

@@ -167,6 +167,9 @@ public void release(final PoolEntry<T, C> entry, final boolean reusable) {
         }
         final T route = entry.getRoute();
         final PerRoutePool<T, C> perRoutePool = perRouteCache.get(route);
+        if (perRoutePool != null && perRoutePool.getCount(entry) == 0) {
+            return;
+        }
         if (perRoutePool != null) {
             final long count = perRoutePool.release(entry, reusable);
             if (count > 0) {