IF() is incorrect when using hex constant

Consider the following:

select  IF(r_regionkey >= 0x40000000, r_regionkey+10, r_regionkey)   page from region cc order by 1 ;

This returns r_regionkey+10, even though all r_regionkey are < 5.

Replacing 0x40000000 with it's base 10 equivalent (1073741824) does not exhibit the bug.

Debugging shows that the constant column is malformed when it reaches the IF function.

This is a regression in 1.5. columnstore 1.4.4 returns the correct response, and debugging shows the constant column is correct.