Using QDataStream to write and read QPalette objects, and the processing result is different in QT5.7 from Q5.12

I write a QPalette object and save it in a file with QDataStream in Qt5.7. Then I need restore it in Qt5.12. But I found that the read result is wrong.
I compared the file qpalette.cpp of Qt5.7 and Qt5.12, and I found that there is a problem with the code.
In the qpalette.cpp of Qt5.12, a new member was inserted before the member NColorRoles of the enumerating variable ColorRole, which made the relationship between

NColorRoles = ToolTipText + 1 not valid,
but NColorRoles was used where ToolTipText + 1 should be used in the code.
Line 1004 and 1042 in qpalette.cpp of Qt5.12:
Int max = QPalette:: NColorRoles;           the value of max is 21;
In version 5.7:
Int max = QPalette:: ToolTipText + 1;       the value of max is 20.