fix issues

src/libxrpl/ledger/helpers/AccountRootHelpers.cpp

@@ -14,7 +14,7 @@ namespace xrpl {
 bool
 AccountRoot::isGlobalFrozen() const
 {
-    if (isXRP(id_))
+    if (!exists())
         return false;
     return sle_->isFlag(lsfGlobalFreeze);
 }
@@ -64,6 +64,9 @@ confineOwnerCount(
 XRPAmount
 AccountRoot::xrpLiquid(std::int32_t ownerCountAdj, beast::Journal j) const
 {
+    if (!exists())
+        return beast::zero;
+
     // Return balance minus reserve
     std::uint32_t const ownerCount = confineOwnerCount(
         readView_.ownerCountHook(id_, sle_->getFieldU32(sfOwnerCount)), ownerCountAdj);

src/libxrpl/ledger/helpers/RippleStateHelpers.cpp

@@ -563,7 +563,7 @@ canTransfer(ReadView const& view, Issue const& issue, AccountID const& from, Acc
     if (issuerId == from || issuerId == to)
         return tesSUCCESS;
     auto const issuer = AccountRoot(issuerId, view);
-    if (issuer.exists())
+    if (!issuer.exists())
         return tefINTERNAL;  // LCOV_EXCL_LINE
 
     auto const isRippleDisabled = [&](AccountID account) -> bool {

src/xrpld/rpc/detail/TransactionSign.cpp

@@ -461,7 +461,7 @@ transactionPreProcessImpl(
     if (verify)
         acctSrc.emplace(srcAddressID, *app.openLedger().current());
 
-    if (verify && !acctSrc.value() && acctSrc->exists())
+    if (verify && acctSrc.has_value() && !acctSrc->exists())
     {
         // If not offline and did not find account, error.
         JLOG(j.debug()) << "transactionSign: Failed to find source account "