[Libdbi-drivers-devel] Bugreport: `atoll` used for converting raw MySQL row data, even for unsigned types

[Rehbein, A. <ale...@fo...>]

Dear developers,


I stumbled across a problem where the queried value


`72623859790382856`  (in hex: `0xFF01020304050607`)


wasn't converted correctly when reading data from a `MYSQL_ROW`.

The cause:

In `_get_row_data`, no distinction is made between signed/unsigned integer types, so if a `MYSQL_ROW` holds, for instance, a string representation of a `uint64_t` that is too large for an `int64_t`, then `_get_row_data` will still call `atoll` to convert it, and we get undefined behavior.


I haven't encountered corresponding errors for other integer types, because the values I had been using so far were too small in those cases, but the problem persists for *any* integer type (a distinction needs to be made).


Regards

Alexander Rehbein