miner: fix addPackageTxs unsigned integer overflow

Author: ismaelsadeeq

src/node/miner.cpp

@@ -392,6 +392,7 @@ void BlockAssembler::addPackageTxs(int& nPackagesSelected, int& nDescendantsUpda
     // close to full; this is just a simple heuristic to finish quickly if the
     // mempool has a lot of entries.
     const int64_t MAX_CONSECUTIVE_FAILURES = 1000;
+    constexpr int32_t BLOCK_FULL_ENOUGH_WEIGHT_DELTA = 4000;
     int64_t nConsecutiveFailed = 0;
 
     while (mi != m_mempool.mapTx.get<confidential_score>().end() || !mapModifiedTx.empty()) {
@@ -471,8 +472,8 @@ void BlockAssembler::addPackageTxs(int& nPackagesSelected, int& nDescendantsUpda
 
             ++nConsecutiveFailed;
 
-            if (nConsecutiveFailed > MAX_CONSECUTIVE_FAILURES && nBlockWeight >
-                    nBlockMaxWeight - 4000) {
+            if (nConsecutiveFailed > MAX_CONSECUTIVE_FAILURES && nBlockWeight +
+                    BLOCK_FULL_ENOUGH_WEIGHT_DELTA > nBlockMaxWeight) {
                 // Give up if we're close to full and haven't succeeded in a while
                 break;
             }