DateInput doesn't appear over other elements when in ControlGroup

[lion3ls]

Environment

• Package version(s): 2.3.1
• Browser and OS versions: Chrome 67 & Ubuntu 17.10

Steps to reproduce

import React from "react";

import { ControlGroup } from "@blueprintjs/core";
import { DateInput, IDateFormatProps } from "@blueprintjs/datetime";

const jsDateFormatter: IDateFormatProps = {
  // note that the native implementation of Date functions differs between browsers
  formatDate: date => date.toLocaleDateString(),
  parseDate: str => new Date(str),
  placeholder: "M/D/YYYY",
};

export const App = () => (
  <>
    <ControlGroup>
      <DateInput {...jsDateFormatter} />
    </ControlGroup>
    <ControlGroup>
      <input type="text" className="pt-input" />
    </ControlGroup>
  </>
);

Both DateInput and text input have to be in a ControlGroup. Other popovers do not suffer of the same bug.

Actual behavior

Second input goes over the datepicker popover.

Expected behavior

Datepicker to be over all other elements.

Possible solution

I was able to fix it by setting transform: none on ControlGroup.

import React from "react";

import { ControlGroup } from "@blueprintjs/core";
import { DateInput, IDateFormatProps } from "@blueprintjs/datetime";

const jsDateFormatter: IDateFormatProps = {
  // note that the native implementation of Date functions differs between browsers
  formatDate: date => date.toLocaleDateString(),
  parseDate: str => new Date(str),
  placeholder: "M/D/YYYY",
};

export const App = () => (
  <>
    <ControlGroup style={{ transform: "none" }}>
      <DateInput {...jsDateFormatter} />
    </ControlGroup>
    <ControlGroup>
      <input type="text" className="pt-input" />
    </ControlGroup>
  </>
);

[giladgray]

@Lsuss this is a duplicate of #2368 and will be fixed by #2539