Subject Re: [Firebird-Java] Re: Empty blob query problem
Author William L. Thomson Jr.
On Wed, 2002-07-24 at 16:14, rrokytskyy wrote:
> > To me that function looks strange since it can be passed a value, but
> > the value is not used in the function. So why pass anything?
> i noticed the same. it seems to me that i had some ideas, but did not
> implement them leaving the code somewhere in the middle... i'm really
> sad about that and will fix it as soon as i get some free time.

I will let you slide on that one. Are there other things like that,
which could possible hinder the drivers performance. Not saying that one
does, but if there are others?

> > Anyhow I am pretty sure I made the modification suggested in the
> > right place and do not know where to go or look from here.
> exception you get is thrown in org.firebirdsql.jdbc.FBBlob class. you
> can grep for that particular message. main idea was to prevent read
> access to a newly created blob that has id 0 (nothing was created in
> the database). but from what you write i conclude that id=0 can happen
> even in case of correct code. i'm not sure if id=0 means that blob is
> null or not, this must be found out experimentally.

Well it seems that the exception is only thrown when the blob id ==0 so
what that actually means will require me to dig further into the code to
see where and how that function is called. To know what it's purpose
would be. For the time being I am going to comment it out and see what
the results are.

> > So if you or anyone else has any ideas I will swap out the code,
> > compile, and test. As I am barely learning the C API, I do not think
> > I can be much help other than as a tester. But I will do my part to
> > test if needed.
> it would be really helpful if you could create a test case that
> reproduces this bug. test case should be able to reproduce the bug on
> empty database. in other words it must create table, populate data and
> actually reproduce data. this will allow us to concentrate on fixing
> the bug and not on trying to reproduce it.

I will look into that but no guarantees. I may have time later today or
tomorrow to do this, but if I do have the time. I will be nasty and ugly
and will not have to much error correction stuff. Just what it takes to
create that same error.

> thanks!
> roman

William L. Thomson Jr.
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