Wrong code for indexed generic in returned type

[timocov]

Bug report

Input code

export interface Ohlc {
	open: number;
	high: number;
	low: number;
	close: number;
}

export interface BarValueByType {
	Bar: Ohlc;
	Line: number;
}

export type SeriesType = keyof BarValueByType;

export function getBarValue<T extends SeriesType>(value: number, seriesType: T): BarValueByType[T] {
	if (seriesType === 'Bar') {
		return {
			open: value,
			high: value,
			low: value,
			close: value,
		} as BarValueByType[T];
	} else {
		return value as BarValueByType[T];
	}
}

Expected output

"use strict";
Object.defineProperty(exports, "__esModule", { value: true });
exports.getBarValue = void 0;
function getBarValue(value, seriesType) {
    if (seriesType === 'Bar') {
        return {
            open: value,
            high: value,
            low: value,
            close: value,
        };
    }
    else {
        return value;
    }
}
exports.getBarValue = getBarValue;

Actual output

"use strict";
Object.defineProperty(exports, "__esModule", { value: true });
exports.getBarValue = void 0;
function getBarValue(value, seriesType) {
    if (seriesType === 'Bar') {
        return {
            _internal_open: value,
            _internal_high: value,
            _internal_low: value,
            _internal_close: value,
        };
    }
    else {
        return value;
    }
}
exports.getBarValue = getBarValue;