Merge #492: check amount against MAX_MONEY with unsigned comparison

36a40e8 check amount against MAX_MONEY with unsigned comparison (Dmitry Petukhov)

Pull request description:

  Because explicit conversion of arbitrarily large unsigned values
  to signed values of the same bit width is implementation defined
  until c++20, better check against MAX_MONEY with unsigned comparison.

Tree-SHA512: c4c40a7126b66e7d1c18750a7151619ab76d48098139a800cbf2123dc5f52091c07508c75846415d05ac67d1d21da71bc30d726e120bf35480a48d85df3e7fe5

src/blind.cpp

@@ -95,7 +95,7 @@ bool UnblindConfidentialPair(const CKey &key, const CConfidentialValue& confValu
     }
 
     // Value sidechannel must be a transaction-valid amount (should be belt-and-suspenders check)
-    if (!MoneyRange((CAmount)amount)) {
+    if (amount > (uint64_t)MAX_MONEY || !MoneyRange((CAmount)amount)) {
         return false;
     }