This bug was initially noticed by GLDS using IBO componnets an then reproduced by me using pure API. Attached test program must output:

conversion error from string "--2"
Dynamic SQL Error
-SQL error code = -104
-Token unknown - line 1, column 9
-*
Dynamic SQL Error
-SQL error code = -104
-Token unknown - line 1, column 9
-*
conversion error from string "--2"
Second OK

Though correct one must be:

conversion error from string "--2"
Dynamic SQL Error
-SQL error code = -104
-Token unknown - line 1, column 9
-*
Dynamic SQL Error
-SQL error code = -104
-Token unknown - line 1, column 9
-*
First OK
Second OK