Add comment on witness-null issuance transactions' invalidity

Author: instagibbs

src/validation.cpp

@@ -862,6 +862,9 @@ bool VerifyAmounts(const CCoinsViewCache& cache, const CTransaction& tx, std::ve
             return false;
         }
         if (!issuance.nAmount.IsNull()) {
+            // Note: This check disallows issuances in transactions with *no* witness data.
+            // This can be relaxed in a future update as a HF by passing in an empty rangeproof
+            // to `VerifyIssuanceAmount` instead.
             if (i >= tx.wit.vtxinwit.size()) {
                 return false;
             }
@@ -889,6 +892,9 @@ bool VerifyAmounts(const CCoinsViewCache& cache, const CTransaction& tx, std::ve
                 return false;
             }
 
+            // Note: This check disallows issuances in transactions with *no* witness data.
+            // This can be relaxed in a future update as a HF by passing in an empty rangeproof
+            // to `VerifyIssuanceAmount` instead.
             if (i >= tx.wit.vtxinwit.size()) {
                 return false;
             }