[Reg 5.8 -> 5.9 RC] Qt Quick Controls 2: Page content whith anchor.fill: parent can appear below header and footer

When navigating using a StackView, if the first page does not contain a header and/or footer but the next page does, using anchor.fill ignores the header and footer, resulting in the content being displayed behind the header and the footer.

Steps to reproduce:
1. Have both Qt 5.8 and Qt 5.9 installed
2. Compile and run the attached program with Qt 5.8
3. Observe that the search page content displays fine after clicking the Search button.
4. Compile and run the attached program with Qt 5.9
5. Observe that the search field appears below the header.

Notes:
Note that when setting the Search.qml as the initial StackView item does not cause the issue.
Note that this issue also occurs in the iOS Simulator.