Reapply "Merge pull request ElementsProject#1391 from apoelstra/2025-02--misc-fuzz-fixes"

This reverts commit acbb8b5.

Author: psgreco

src/primitives/confidential.h

@@ -135,6 +135,11 @@ class CConfidentialValue : public CConfidentialCommitment<9, 8, 9>
     CConfidentialValue() { SetNull(); }
     CConfidentialValue(CAmount nAmount) { SetToAmount(nAmount); }
 
+    template <typename Stream>
+    inline void Unserialize(Stream& s) {
+        CConfidentialCommitment::Unserialize(s);
+    }
+
     /* An explicit value is called an amount. The first byte indicates it is
      * an explicit value, and the remaining 8 bytes is the value serialized as
      * a 64-bit big-endian integer. */

src/primitives/transaction.h

@@ -295,6 +295,9 @@ class CTxOut
             s >> nAsset;
             s >> nValue;
             s >> nNonce;
+            if (nAsset.IsNull() || nValue.IsNull()) {
+                throw std::ios_base::failure("Confidential values may not be null");
+            }
         } else {
             CAmount value;
             s >> value;

src/test/fuzz/rbf.cpp

@@ -15,7 +15,13 @@
 #include <string>
 #include <vector>
 
-FUZZ_TARGET(rbf)
+void initialize_rbf(void) {
+    // ELEMENTS: our mempool needs Params() to be set for multiple reasons -- to check
+    //  the discount CT rate, to figure out pegin policy, etc
+    SelectParams(CBaseChainParams::LIQUID1);
+}
+
+FUZZ_TARGET_INIT(rbf, initialize_rbf)
 {
     FuzzedDataProvider fuzzed_data_provider(buffer.data(), buffer.size());
     SetMockTime(ConsumeTime(fuzzed_data_provider));