Subject Subtle Bug in RequestLive setting
Author larrybaddock
Hi, All.

There is a subtle bug in the changing of requestlive, in IBO 4.3A. It
only seems to affect binary (AsRawString) parameters for the query, if
there is a Character 0 in the parameter. There may be other
circumstances as well that I am not aware of.

Example, assuming statement is already prepared, and the requestlive
was initially false for the prepare:

1 q.RequestLive:=true;
2 q.ParamByName('UOID').AsRawString:=#55#56#57#0#58#59;
3 q.Open;
4 Anything_you_like;

After line 2 is executed, all is still fine. Reading
'q.ParamByName('UOID').AsRawString' from the Delphi debugger reveals
the correct value, of #55#56#57#0#58#59.
However, as soon as line 3 is executed, the value of
'q.ParamByName('UOID').AsRawString' has been silently changed, and now
gets truncated at the 0, leaving a value of #55#56#57.
The net result is that at line 4, you assume you are looking at a
query that contains what you expect, but it actually contains
something else altogether. The parameter that is sent through to the
database engine is the truncated value.

Although it does not affect most people (I would imagine that there is
not a lot of binary data in most database columns outside blobs), it
is pretty serious if you have a binary GUID, for example, in a 16 byte
OCTETS field. This type of practice is increasing in popularity.

Anyone who is doing this, for now, be VERY careful, and unprepare the
query (if the requestlive was initially false, and needs to be true),
change the requestlive to true and reprepare the query. If you don't,
be prepared to be bitten.

Jonathan, please have a look into this.

Many thanks

Kind regards