address comments

src/libxrpl/tx/invariants/MPTInvariant.cpp

@@ -40,6 +40,7 @@ constexpr auto kConfidentialMptTxTypes = std::to_array<TxType>({
     ttCONFIDENTIAL_MPT_CONVERT_BACK,
     ttCONFIDENTIAL_MPT_MERGE_INBOX,
     ttCONFIDENTIAL_MPT_CLAWBACK,
+    ttCONFIDENTIAL_MPT_MIRROR_UPDATE,
 });
 
 // Clamp to the cap (== INT64_MAX) before the signed conversion. Invariant

src/libxrpl/tx/transactors/token/ConfidentialMPTMirrorUpdate.cpp

@@ -214,7 +214,7 @@ ConfidentialMPTMirrorUpdate::doApply()
         UNREACHABLE(
             "xrpl::ConfidentialMPTMirrorUpdate::doApply : preclaim already validated the "
             "issuance exists");
-        return tefINTERNAL;
+        return tecINTERNAL;
         // LCOV_EXCL_STOP
     }
 
@@ -229,7 +229,7 @@ ConfidentialMPTMirrorUpdate::doApply()
         UNREACHABLE(
             "xrpl::ConfidentialMPTMirrorUpdate::doApply : preclaim already validated the "
             "MPToken exists");
-        return tefINTERNAL;
+        return tecINTERNAL;
         // LCOV_EXCL_STOP
     }