On 18 Jul 2019, at 23:18, Vladislav Shpilevoy <v.shpilevoy@tarantool.org> wrote:

Hi!

Thanks for the fixes!

-------------------------
vdbe.c:307

case FIELD_TYPE_INTEGER:
case FIELD_TYPE_UNSIGNED:
if ((record->flags & MEM_Int) == MEM_Int)
return 0;
if ((record->flags & MEM_UInt) == MEM_UInt)
return 0;
if ((record->flags & MEM_Real) == MEM_Real) {
int64_t i = (int64_t) record->u.r;
if (i == record->u.r)
mem_set_int(record, record->u.r,
    record->u.r <= -1);
return 0;
}

It is a part of function mem_apply_type. When target type is
UNSIGNED, and a value is MEM_Int, you do nothing. Why? Looks like
it is possible to pass here a negative value, and CAST UNSIGNED
would do nothing.

Basically, this function implements sort of implicit cast
which takes place before comparison/assignment.
For comparisons it makes no sense - we can compare
integer with unsigned value - the latter is always greater.
For assignment it is also meaningless: if we attempt
at inserting negative values to unsigned field appropriate
error will be raised anyway. If you can come up with
specific example, let’s discuss it.

I can't provide a test. But the function is named mem_apply_type,
and it doesn't apply type, when it is unsigned, and a value is
negative. Doesn't it look wrong to you?

If some code wants to get an integer, it can apply FIELD_TYPE_INTEGER
instead of FIELD_TYPE_UNSIGNED. IMO, an attempt to apply unsigned
to int should raise an error here. Otherwise this function can't
be named 'apply_type' because it ignores negative -> unsigned case.