QT_DISTANCEFIELD_DEFAULT_BASEFONTSIZE=128 causes a QDistanceField crash

How to reproduce the issue:

• Run the attached reproducer with enabling the code in main() below :

  qputenv("QT_DISTANCEFIELD_DEFAULT_BASEFONTSIZE", "128"); 

Then the application crashes. 
The issue was reproduced with the value "86" or larger, while it is not reproduced with "85" or smaller.
The user, reported this issue, needs it to be 128.