Commented by: @mrotteveel

To check:
* Database characterset ISO8859_1 using NONE and UTF8 connection characterset

Commented by: @mrotteveel

With a database created with default characterset ISO8859_1, connection characterset NONE does work, UTF8 still returns an error.

Commented by: @mrotteveel

Simplified reproduction script using native library (see included readme.txt)

Commented by: @mrotteveel

Found the cause. The data array in the XSQLVAR was shorter than the sqllen defined, either reducing the sqllen to the actual length or padding the data array seems to fix it.

Padding might be the required course of action, because I believe the XSQLVARs are reused for multiple executions, and reducing the sqllen would break things.

Commented by: @mrotteveel

Found a workaround: Cast the parameter to a VARCHAR of the same type
eg change:
INSERT INTO TEST (TEST_FIELD) VALUES(?)
to:
INSERT INTO TEST (TEST_FIELD) VALUES(CAST(? AS VARCHAR(1)))

Commented by: @mrotteveel

It looks like the code in xsqlda_wrapper.cpp should take care of padding, I need to find out why it isn't actually being executed for the SQL_TEXT.

Commented by: @mrotteveel

That padding code also contains a (potential) bug for character set NONE: It seems to be padding use 0x20 always, while I think NONE should pad with 0x00.

Commented by: @mrotteveel

Found the problem. The code for copying the Java XSQLVAR to a native XSQLVAR would first assign the (java) byte array size (two bytes) to the sqldata field, and then overwrite it with the bytearray. This poses no problem for any structure longer than two bytes, but in the case of single byte characters (in any encoding), this would cause a buffer overflow. In the case of single byte encodings this would not be a big problem (as the data area is 1 byte bigger then needed), but for UTF8 it would cause the padding to be overwritten by an unexpected byte value (eg for 'W' it would write out 0x57 0x00 0x20 0x20 instead of the expected 0x57 0x20 0x20 0x20.

I also expect this could introduce unexpected characters in CHAR fields with a size longer than 1 when a single character is assigned.