Invalid cast on nullable custom type with Linq

[gokhanabatay]

Hi,
We are trying to upgrade NH 5.3, that we have been waiting for along time.
We come across an issue, I implemented below test cases

https://github.com/gokhanabatay/NHibernateBugTest/blob/master/NHibernateBugTest/CustomTypeSelectFailsTest.cs

Get_DateCustomType_NullableDateValueEquals_IncorrectCast

select usersessio0_.GUID as guid1_5_, usersessio0_.MBR_ID as mbr2_5_, usersessio0_.USER_CODE as user3_5_, 
    usersessio0_.OPEN_DATE as open4_5_, usersessio0_.EXPIRE_DATE_TIME as expire5_5_,
    usersessio0_.IS_OPEN as is6_5_, usersessio0_.REMOTE_IP_ADDRESS as remote7_5_,
    usersessio0_.REMOTE_PORT as remote8_5_, usersessio0_.LOCAL_IP_ADDRESS as local9_5_,
    usersessio0_.LOCAL_PORT as local10_5_, usersessio0_.DEVICE_ID as device11_5_,
    usersessio0_.CLAIMS as claims12_5_ 
  from USER_SESSION usersessio0_
  where usersessio0_.MBR_ID = :p0 and cast(usersessio0_.OPEN_DATE as timestamp)=:p1 ]

Above sql includes cast(usersessio0_.OPEN_DATE as timestamp) but open_date is a number field in database. It is working with 5.2.7 and previous versions.

Get_BooleanCustomType_Fails_IncorrectCast

select cast(user1_.IS_OPEN as boolean) as col_0_0_
  from USER_SESSION usersessio0_
  left outer join ALL_USER user1_ on usersessio0_.USER_CODE=user1_.USER_CODE
  where usersessio0_.MBR_ID = :p0 and usersessio0_.OPEN_DATE=:p1 

Above sql includes cast(user1_.IS_OPEN as boolean) as col_0_0_ but is_open field is a number field. It is also working with 5.2.7 and previous versions.

[hazzik]

Fixed by #2438