From fe3bfc2f45d0f2b3d291386879e28eaecf1dfd62 Mon Sep 17 00:00:00 2001
From: shantichanal <158101918+shantichanal@users.noreply.github.com>
Date: Tue, 15 Jul 2025 17:42:11 +0200
Subject: [PATCH] Updated code and new test

Noticed that the parent hash was not being set. The way we do getHash relies on the parentHash to be cached correctly, so setting the parentHash after doing makeHeader fixes the issue.
---
 eth/tracers/api.go      | 18 +++++++++++-------
 eth/tracers/api_test.go | 22 ++++++++++++++++++++++
 2 files changed, 33 insertions(+), 7 deletions(-)

diff --git a/eth/tracers/api.go b/eth/tracers/api.go
index dccd12a35f..5a60766373 100644
--- a/eth/tracers/api.go
+++ b/eth/tracers/api.go
@@ -953,15 +953,19 @@ func (api *API) TraceCall(ctx context.Context, args ethapi.TransactionArgs, bloc
 	}
 	defer release()
 
-	// Apply block override to header to ensure GetHashFn works correctly with
-	// blocks in the future (#32175).
-	h := block.Header()
-	if config != nil {
-		h = config.BlockOverrides.MakeHeader(h)
+	h := *block.Header()
+
+	if config != nil && config.BlockOverrides != nil {
+		h = *config.BlockOverrides.MakeHeader(block.Header())
+		if h.Number.Uint64() == block.NumberU64()+1 {
+			h.ParentHash = block.Hash()
+		} else if h.Number.Uint64() > block.NumberU64()+1 {
+			h.ParentHash = common.Hash{}
+		}
 	}
 
-	// Apply block overrides to block context, if applicable.
-	vmctx := core.NewEVMBlockContext(h, api.chainContext(ctx), nil)
+	vmctx := core.NewEVMBlockContext(&h, api.chainContext(ctx), nil)
+	// Apply the customization rules if required.
 	if config != nil {
 		if overrideErr := config.BlockOverrides.Apply(&vmctx); overrideErr != nil {
 			return nil, overrideErr
diff --git a/eth/tracers/api_test.go b/eth/tracers/api_test.go
index 048978fcd0..670f9f1186 100644
--- a/eth/tracers/api_test.go
+++ b/eth/tracers/api_test.go
@@ -689,6 +689,9 @@ func TestTracingWithOverrides(t *testing.T) {
 		Failed      bool
 		ReturnValue string
 	}
+	overrideBlockNumber := genBlocks + 1
+	parentHash := backend.chain.GetHeaderByNumber(uint64(genBlocks)).Hash().Hex()[2:]
+	expectParent := fmt.Sprintf("0x%064s", parentHash)
 
 	var testSuite = []struct {
 		blockNumber rpc.BlockNumber
@@ -789,6 +792,25 @@ func TestTracingWithOverrides(t *testing.T) {
 			},
 			want: `{"gas":72666,"failed":false,"returnValue":"0x000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000"}`,
 		},
+		{ // Override blocknumber, and query a blockhash
+			blockNumber: rpc.LatestBlockNumber,
+			call: ethapi.TransactionArgs{
+				From: &accounts[0].addr,
+				Input: newRPCBytes([]byte{
+					byte(vm.PUSH1), byte(genBlocks),
+					byte(vm.BLOCKHASH),
+					byte(vm.PUSH1), 0x00,
+					byte(vm.MSTORE),
+					byte(vm.PUSH1), 0x20,
+					byte(vm.PUSH1), 0x00,
+					byte(vm.RETURN),
+				}), // blocknumber
+			},
+			config: &TraceCallConfig{
+				BlockOverrides: &override.BlockOverrides{Number: (*hexutil.Big)(big.NewInt(int64(overrideBlockNumber)))},
+			},
+			want: fmt.Sprintf(`{"gas":59590,"failed":false,"returnValue":"%s"}`, expectParent),
+		},
 		/*
 			pragma solidity =0.8.12;