migrate createMPToken, reduce diff

include/xrpl/ledger/helpers/AccountRootHelpers.h

@@ -125,8 +125,7 @@ ownerCount(SLE::const_ref sle, beast::Journal j, std::int32_t ownerCountAdj = 0)
  *  and the sponsor's sponsoring count.
  *
  *  @param view The apply view for making changes
- *  @param accountSle The account's ledger entry
- *  @param sponsorSle The sponsor's ledger entry (if applicable)
+ *  @param reserveCtx The account and sponsor information
  *  @param count Amount to add to the owner count
  *  @param j Journal for logging
  */
@@ -145,8 +144,7 @@ increaseOwnerCount(
  *  sfSponsor field.
  *
  *  @param view The apply view for making changes
- *  @param accountSle The account's ledger entry
- *  @param sponsorSle The sponsor's ledger entry (if applicable)
+ *  @param reserveCtx The account and sponsor information
  *  @param count Amount to remove from the owner count
  *  @param j Journal for logging
  */
@@ -157,19 +155,23 @@ decreaseOwnerCount(
     std::uint32_t count,
     beast::Journal j);
 
-/** Decrease the owner counters of the account. If the object has a sponsor,
- *  adjust its counters too. Used primarily just before deleting the object.
+/** Decrease owner-count fields for an existing ledger object.
+ *
+ *  This helper derives the reserve sponsor from objectSle's sfSponsor field,
+ *  then updates the same owner-count fields as decreaseOwnerCount. Use this
+ *  when removing an existing object whose reserve sponsor is stored on that
+ *  object.
  *
  *  @param view The apply view for making changes
- *  @param ownerSle The account's ledger entry
+ *  @param accountSle The account's ledger entry
  *  @param objectSle The object's ledger entry
- *  @param count Positive amount to remove from the owner count
- *  @param j Journal for logging (default: null sink)
+ *  @param count Amount to remove from the owner count
+ *  @param j Journal for logging
  */
 void
 decreaseOwnerCountForObject(
     ApplyView& view,
-    SLE::pointer ownerSle,
+    SLE::ref accountSle,
     SLE::ref objectSle,
     std::uint32_t count,
     beast::Journal j);

include/xrpl/ledger/helpers/EscrowHelpers.h

@@ -196,24 +196,21 @@ escrowUnlockApplyHelper<MPTIssue>(
     auto const mptKeylet = keylet::mptoken(issuanceKey.key, receiver);
     if (!ctx.view.exists(mptKeylet) && createAsset && !receiverIssuer)
     {
-        auto const sponsorSle = ctx.txReserveContext.sponsorSle;
-
         if (auto const ret =
                 checkInsufficientReserve(ctx, sleDest, xrpBalance, {.ownerCountDelta = 1}, journal);
             !isTesSuccess(ret))
             return ret;
 
-        if (auto const ter = createMPToken(ctx.view, mptID, receiver, sponsorSle, 0);
-            !isTesSuccess(ter))
+        auto const reserveCtx =
+            ReserveContext::makeFromAccount(ctx.view, sleDest, ctx.txReserveContext.sponsorSle);
+
+        if (auto const ter = createMPToken(ctx.view, mptID, reserveCtx, 0); !isTesSuccess(ter))
         {
             return ter;  // LCOV_EXCL_LINE
         }
 
         // update owner count.
-        increaseOwnerCount(
-            ctx.view, ReserveContext::makeFromAccount(ctx.view, sleDest, sponsorSle), 1, journal);
-        auto mptSle = ctx.view.peek(mptKeylet);
-        addSponsorToLedgerEntry(mptSle, sponsorSle);
+        increaseOwnerCount(ctx.view, reserveCtx, 1, journal);
     }
 
     if (!ctx.view.exists(mptKeylet) && !receiverIssuer)

include/xrpl/ledger/helpers/MPTokenHelpers.h

@@ -242,8 +242,7 @@ TER
 createMPToken(
     ApplyView& view,
     MPTID const& mptIssuanceID,
-    AccountID const& account,
-    SLE::ref sponsorSle,
+    ReserveContext const& reserveCtx,
     std::uint32_t const flags);
 
 TER