Incorrect GasRefund in debug_traceCall with custom tracer

[quickchase]

System information

Geth version: 1.10.23
OS & Version: Linux

Expected behaviour

GasRefund should be greater than 0

Actual behaviour

{"jsonrpc":"2.0","id":"1","result":{"refund":0,"gasUsed":140031}}

Steps to reproduce the behaviour

Using the following request:

{
    "id": "1",
    "jsonrpc": "2.0",
    "method": "debug_traceCall",
    "params": [
        {
            "from": "0xbe0eb53f46cd790cd13851d5eff43d12404d33e8",
            "data": "0xe449022e0000000000000000000000000000000000000000000000000de0b6b3a7640000000000000000000000000000000000000000000000000033f473f10467f04eaa00000000000000000000000000000000000000000000000000000000000000600000000000000000000000000000000000000000000000000000000000000001c0000000000000000000000060594a405d53811d3bc4766596efd80fd545a270",
            "value": "0xDE0B6B3A7640000",
            "to": "0x1111111254fb6c44bac0bed2854e76f90643097d"
        },
        "latest",
        {
            "tracer": "{\n    accumulatedGasRefund: 0,\n\n    fault: function (log, db, err) {\n    },\n\n    step: function (log, db) {\n        // SSTORE\n        if (log.op.toNumber() !== 0x55) {\n            return\n        }\n\n        this.accumulatedGasRefund = log.getRefund()\n    },\n\n    result: function (ctx, db) {\n        var gasUsed = ctx.gasUsed + ctx.intrinsicGas\n\n        var maxGasRefund = Math.trunc(gasUsed / 5)\n\n        var resultGasRefund = Math.min(this.accumulatedGasRefund, maxGasRefund)\n\n        return {\n  refund: resultGasRefund,gasUsed: ctx.gasUsed + ctx.intrinsicGas - resultGasRefund,\n        };\n    }\n\n}\n"
        }
    ]
}

[holiman]

{
    accumulatedGasRefund: 0,

    fault: function (log, db, err) {
    },

    step: function (log, db) {
        // SSTORE
        if (log.op.toNumber() !== 0x55) {
            return
        }
        this.accumulatedGasRefund = log.getRefund()
    },

    result: function (ctx, db) {
        var gasUsed = ctx.gasUsed + ctx.intrinsicGas
        var maxGasRefund = Math.trunc(gasUsed / 5)
        var resultGasRefund = Math.min(this.accumulatedGasRefund, maxGasRefund)
        return {
  			refund: resultGasRefund,
			gasUsed: ctx.gasUsed + ctx.intrinsicGas - resultGasRefund,
        };
    }
}