FarmerGerminatingStalkBalanceChanged adjust for event bug

projects/subgraph-beanstalk/schema.graphql

@@ -1472,6 +1472,19 @@ type Germinating @entity {
   bdv: BigInt!
 }
 
+# This entity exists solely for resolving the issue in LibGerminate when deposits from multiple seasons
+# complete their germination (the event emission itself has a bug)
+type PrevFarmerGerminatingEvent @entity {
+  "Farmer address"
+  id: Bytes!
+  "The `block.number` of the `FarmerGerminatingStalkBalanceChanged` event"
+  eventBlock: BigInt!
+  "The `logIndex` of the `FarmerGerminatingStalkBalanceChanged` event"
+  logIndex: BigInt!
+  "The value for `deltaGerminatingStalk` from this previous `FarmerGerminatingStalkBalanceChanged` event."
+  deltaGerminatingStalk: BigInt!
+}
+
 type UnripeToken @entity {
   "Token Address"
   id: Bytes!

projects/subgraph-beanstalk/src/entities/Germinating.ts

@@ -1,6 +1,6 @@
-import { Address, BigDecimal, BigInt, store } from "@graphprotocol/graph-ts";
-import { toDecimal, ZERO_BD, ZERO_BI } from "../../../subgraph-core/utils/Decimals";
-import { Germinating } from "../../generated/schema";
+import { Address, BigDecimal, BigInt, ethereum, store } from "@graphprotocol/graph-ts";
+import { ONE_BI, toDecimal, ZERO_BD, ZERO_BI } from "../../../subgraph-core/utils/Decimals";
+import { Germinating, PrevFarmerGerminatingEvent } from "../../generated/schema";
 
 export function loadOrCreateGerminating(address: Address, season: i32, isFarmer: boolean): Germinating {
   const type = germinationSeasonCategory(season);
@@ -42,6 +42,37 @@ export function deleteGerminating(germinating: Germinating): void {
   store.remove("Germinating", germinating.id);
 }
 
+// This is the entity that exists to resolve the issue in LibGerminate when deposits from multiple seasons
+// complete their germination (the event emission itself has a bug)
+export function loadPrevFarmerGerminatingEvent(account: Address): PrevFarmerGerminatingEvent {
+  let savedEvent = PrevFarmerGerminatingEvent.load(account);
+  if (savedEvent == null) {
+    savedEvent = new PrevFarmerGerminatingEvent(account);
+    savedEvent.eventBlock = ZERO_BI;
+    savedEvent.logIndex = ZERO_BI;
+    savedEvent.deltaGerminatingStalk = ZERO_BI;
+    // No point in saving it
+  }
+  return savedEvent as PrevFarmerGerminatingEvent;
+}
+
+export function savePrevFarmerGerminatingEvent(account: Address, event: ethereum.Event, deltaGerminatingStalk: BigInt): void {
+  const savedEvent = new PrevFarmerGerminatingEvent(account);
+  savedEvent.eventBlock = event.block.number;
+  savedEvent.logIndex = event.logIndex;
+  savedEvent.deltaGerminatingStalk = deltaGerminatingStalk;
+  savedEvent.save();
+}
+
+// Returns the stalk offset that should be applied to the encountered FarmerGerminatingStalkBalanceChanged event.
+export function getFarmerGerminatingBugOffset(account: Address, event: ethereum.Event): BigInt {
+  const prevEvent = loadPrevFarmerGerminatingEvent(account);
+  if (prevEvent.eventBlock == event.block.number && prevEvent.logIndex == event.logIndex.minus(ONE_BI)) {
+    return prevEvent.deltaGerminatingStalk.neg();
+  }
+  return ZERO_BI;
+}
+
 function germinationSeasonCategory(season: i32): string {
   return season % 2 == 0 ? "EVEN" : "ODD";
 }

projects/subgraph-beanstalk/src/handlers/GaugeHandler.ts

@@ -8,7 +8,13 @@ import {
   TotalGerminatingStalkChanged,
   TotalStalkChangedFromGermination
 } from "../../generated/Beanstalk-ABIs/SeedGauge";
-import { deleteGerminating, loadGerminating, loadOrCreateGerminating } from "../entities/Germinating";
+import {
+  deleteGerminating,
+  getFarmerGerminatingBugOffset,
+  loadGerminating,
+  loadOrCreateGerminating,
+  savePrevFarmerGerminatingEvent
+} from "../entities/Germinating";
 import { BI_10, ZERO_BI } from "../../../subgraph-core/utils/Decimals";
 import { BEAN_WETH_CP2_WELL } from "../../../subgraph-core/utils/Constants";
 import { Bytes4_emptyToNull } from "../../../subgraph-core/utils/Bytes";
@@ -71,9 +77,13 @@ export function handleFarmerGerminatingStalkBalanceChanged(event: FarmerGerminat
     farmerGerminating.stalk = farmerGerminating.stalk.plus(event.params.deltaGerminatingStalk);
     farmerGerminating.save();
   } else {
+    // Adjusts for the event's inherent bug when both even/odd germination complete in the same txn
+    const bugfixStalkOffset = getFarmerGerminatingBugOffset(event.params.account, event);
+    const actualDeltaGerminatingStalk = event.params.deltaGerminatingStalk.plus(bugfixStalkOffset);
+
     // Germinating stalk is being removed. It therefore must have created the entity already
     let farmerGerminating = loadGerminating(event.params.account, event.params.germinationState);
-    farmerGerminating.stalk = farmerGerminating.stalk.plus(event.params.deltaGerminatingStalk);
+    farmerGerminating.stalk = farmerGerminating.stalk.plus(actualDeltaGerminatingStalk);
     if (farmerGerminating.stalk == ZERO_BI) {
       deleteGerminating(farmerGerminating);
     } else {
@@ -84,10 +94,13 @@ export function handleFarmerGerminatingStalkBalanceChanged(event: FarmerGerminat
       // If germination finished, need to subtract stalk from system silo. This stalk was already added
       // into system stalk upon sunrise for season - 2.
       let systemSilo = loadSilo(event.address);
-      systemSilo.stalk = systemSilo.stalk.plus(event.params.deltaGerminatingStalk);
+      systemSilo.stalk = systemSilo.stalk.plus(actualDeltaGerminatingStalk);
       takeSiloSnapshots(systemSilo, event.address, event.block.timestamp);
       systemSilo.save();
     }
+
+    // Also for the event bug adjustment
+    savePrevFarmerGerminatingEvent(event.params.account, event, event.params.deltaGerminatingStalk);
   }
 
   let farmerSilo = loadSilo(event.params.account);