Fix payback to account for negative interest (#1447)

* Add FortCanningEpilogue fork * Fix payback not to reduce negative interest from wallet. Imrpove tests. Co-authored-by: Peter Bushnell <[email protected]>
DeFiCh · Sep 9, 2022 · 76987d1 · 76987d1
1 parent 3e3d1d8
commit 76987d1
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Showing 3 changed files with 232 additions and 73 deletions.
diff --git a/src/masternodes/mn_checks.cpp b/src/masternodes/mn_checks.cpp
@@ -3133,14 +3133,14 @@ class CCustomTxApplyVisitor : public CCustomTxVisitor
                 const auto totalInterest = TotalInterest(*rate, height);
 
                 if (totalInterest < 0) {
-                    loanAmountChange = currentLoanAmount > std::abs(totalInterest) ? 
+                    loanAmountChange = currentLoanAmount > std::abs(totalInterest) ?
                         // Interest to decrease smaller than overall existing loan amount.
                         // So reduce interest from the borrowing principal. If this is negative,
-                        // we'll reduce from principal. 
-                        tokenAmount + totalInterest : 
+                        // we'll reduce from principal.
+                        tokenAmount + totalInterest :
                         // Interest to decrease is larger than old loan amount.
-                        // We reduce from the borrowing principal. If this is negative, 
-                        // we'll reduce from principal. 
+                        // We reduce from the borrowing principal. If this is negative,
+                        // we'll reduce from principal.
                         tokenAmount - currentLoanAmount;
                     resetInterestToHeight = true;
                 }
@@ -3427,7 +3427,10 @@ class CCustomTxApplyVisitor : public CCustomTxVisitor
                 if (paybackTokenId == loanTokenId)
                 {
                     // If interest was negative remove it from sub amount
-                    res = mnview.SubMintedTokens(loanTokenId, subInterest > 0 ? subLoan : subLoan + subInterest);
+                    if (height >= static_cast<uint32_t>(consensus.FortCanningEpilogueHeight) && subInterest < 0)
+                        subLoan += subInterest;
+
+                    res = mnview.SubMintedTokens(loanTokenId, subLoan);
                     if (!res)
                         return res;