mysql_fetch_lengths() returning array of Int64 on Lazarus/Linux

In Lazarus, I am loading libmariadb.so.3 v3.3.10 via LoadLibrary(). (Did another test with libmysqlclient.so.21 v8.0.41). When iterating through the fields of a query result, the length of a value is indicated by the items of the array returned from mysql_fetch_lengths():

type
  PMYSQL_LENGTHS = ^TMYSQL_LENGTHS;
  TMYSQL_LENGTHS = array[0..4095] of LongWord;

  mysql_fetch_lengths: function(Result: PMYSQL_RES): PMYSQL_LENGTHS; cdecl;

var
  LengthsPointer: PMYSQL_LENGTHS;
begin
  LengthsPointer := mysql_fetch_lengths(FCurrentResults);
  for i := 0 to NumFieldsInResult - 1 do
    ShowMessage(IntToStr(LengthsPointer^[i]));

That worked for years nicely, in Delphi and also in Lazarus with a Windows executable. I am using the same libmysql and libmariadb libraries on Windows as on Linux. Now when I compile the same code in Lazarus for Linux and run it, the TMYSQL_LENGTHS seems to contain Int64 items (with a size of 8 bytes), not LongWord/UInt32 (with a size of 4 bytes). When keeping the LongWord definition, the array loop shows twice as many items as columns exist in the table, with a 0 at each odd index, e.g.:

fieldno LengthsPointer[fieldno]
0       2
1       0
2       10
3       0
4       3
5       0
6       1024
7       0

The documentation clearly states these should be unsigned long integers, even for the newest versions. So I assume I am doing something wrong. Do I?