refactor: Make more transaction size variables signed

This change gets rid of `static_cast`s and compiler warnings.

Author: hebasto

src/txmempool.cpp

@@ -155,12 +155,12 @@ void CTxMemPool::UpdateTransactionsFromBlock(const std::vector<uint256>& vHashes
 }
 
 util::Result<CTxMemPool::setEntries> CTxMemPool::CalculateAncestorsAndCheckLimits(
-    size_t entry_size,
+    int64_t entry_size,
     size_t entry_count,
     CTxMemPoolEntry::Parents& staged_ancestors,
     const Limits& limits) const
 {
-    size_t totalSizeWithAncestors = entry_size;
+    int64_t totalSizeWithAncestors = entry_size;
     setEntries ancestors;
 
     while (!staged_ancestors.empty()) {
@@ -171,11 +171,11 @@ util::Result<CTxMemPool::setEntries> CTxMemPool::CalculateAncestorsAndCheckLimit
         staged_ancestors.erase(stage);
         totalSizeWithAncestors += stageit->GetTxSize();
 
-        if (stageit->GetSizeWithDescendants() + entry_size > static_cast<uint64_t>(limits.descendant_size_vbytes)) {
+        if (stageit->GetSizeWithDescendants() + entry_size > limits.descendant_size_vbytes) {
             return util::Error{Untranslated(strprintf("exceeds descendant size limit for tx %s [limit: %u]", stageit->GetTx().GetHash().ToString(), limits.descendant_size_vbytes))};
         } else if (stageit->GetCountWithDescendants() + entry_count > static_cast<uint64_t>(limits.descendant_count)) {
             return util::Error{Untranslated(strprintf("too many descendants for tx %s [limit: %u]", stageit->GetTx().GetHash().ToString(), limits.descendant_count))};
-        } else if (totalSizeWithAncestors > static_cast<uint64_t>(limits.ancestor_size_vbytes)) {
+        } else if (totalSizeWithAncestors > limits.ancestor_size_vbytes) {
             return util::Error{Untranslated(strprintf("exceeds ancestor size limit [limit: %u]", limits.ancestor_size_vbytes))};
         }
 
@@ -201,7 +201,7 @@ bool CTxMemPool::CheckPackageLimits(const Package& package,
                                     std::string &errString) const
 {
     CTxMemPoolEntry::Parents staged_ancestors;
-    size_t total_size = 0;
+    int64_t total_size = 0;
     for (const auto& tx : package) {
         total_size += GetVirtualTransactionSize(*tx);
         for (const auto& input : tx->vin) {

src/txmempool.h

@@ -442,7 +442,7 @@ class CTxMemPool
      *
      * @return all in-mempool ancestors, or an error if any ancestor or descendant limits were hit
      */
-    util::Result<setEntries> CalculateAncestorsAndCheckLimits(size_t entry_size,
+    util::Result<setEntries> CalculateAncestorsAndCheckLimits(int64_t entry_size,
                                                               size_t entry_count,
                                                               CTxMemPoolEntry::Parents &staged_ancestors,
                                                               const Limits& limits