Merge #2819: [Core] Solve BLS Memleak

a7c6fac Solve BLS Memleak if object not pushed to queue (Liquid)

Pull request description:

  Partial backport of dashpay#5202

  In term of trying to keep memory down, this is a potential bug where if the object was never entered into the queue it just starts to bloat the memory.

ACKs for top commit:
  panleone:
    utACK a7c6fac
  Fuzzbawls:
    utACK a7c6fac

Tree-SHA512: cb375c16bdad455a95ae906dfadefc28647adee69ae0237bbe2b7b38f3b0f980afd483f4c0c5316b53033fd5dd4fc77b74497debff30ca00c7cc48987687e30a

src/bls/bls_worker.cpp

@@ -276,7 +276,13 @@ struct Aggregator : public std::enable_shared_from_this<Aggregator<T>> {
 
     void PushAggQueue(const T& v)
     {
-        aggQueue.push(new T(v));
+        auto copyT = new T(v);
+        try {
+            aggQueue.push(copyT);
+        } catch (...) {
+            delete copyT;
+            throw;
+        }
 
         if (++aggQueueSize >= batchSize) {
             // we've collected enough intermediate results to form a new batch.