fix: remove duplicate ante events

CHANGELOG.md

@@ -224,6 +224,7 @@ extension interfaces. `module.Manager.Modules` is now of type `map[string]interf
 * (x/gov) [#13918](https://github.com/cosmos/cosmos-sdk/pull/13918) Fix propagation of message errors when executing a proposal.
 * (baseapp)[#14049](https://github.com/cosmos/cosmos-sdk/pull/14049) Fix state sync when interval is zero.
 * (store) [#13516](https://github.com/cosmos/cosmos-sdk/pull/13516) Fix state listener that was observing writes at wrong time.
+* (baseapp) [#13983](https://github.com/cosmos/cosmos-sdk/pull/13983) Don't emit duplicate ante-handler events when a post-handler is defined.
 
 ### Deprecated
 

baseapp/baseapp.go

@@ -738,7 +738,12 @@ func (app *BaseApp) runTx(mode runTxMode, txBytes []byte) (gInfo sdk.GasInfo, re
 		//
 		// Note: If the postHandler fails, we also revert the runMsgs state.
 		if app.postHandler != nil {
-			newCtx, err := app.postHandler(runMsgCtx, tx, mode == runTxModeSimulate)
+			// The runMsgCtx context currently contains events emitted by the ante handler.
+			// We clear this to correctly order events without duplicates.
+			// Note that the state is still preserved.
+			postCtx := runMsgCtx.WithEventManager(sdk.NewEventManager())
+
+			newCtx, err := app.postHandler(postCtx, tx, mode == runTxModeSimulate)
 			if err != nil {
 				return gInfo, nil, nil, priority, err
 			}