[osmosis-dev] API 0.6 and unique keys

[marcus.wolschon at googlemail.com]

On Tue, 3 Feb 2009 10:48:26 +1100, Brett Henderson <brett at bretth.com>
wrote:
> On Tue, Feb 3, 2009 at 1:38 AM, <marcus.wolschon at googlemail.com> wrote:
> 
>> On Mon, 2 Feb 2009 15:21:53 +0100, Jochen Topf <jochen at remote.org>
wrote:
>>
>> > I am not sure any more that this JPF magic is the right way to go. At
>> > least not in this current form. We would at least need some kind of
>> > versioning mechanism so that I can get a proper message: "Found plugin
>> > xyz which conflicts bla bla" instead of just giving a null pointer
>> > exception. I rarely use Osmosis from the command line, normally I have
>> > scripts calling it, so I don't mind having some extra command line
>> > options.
>>
>> Actually your NullPointerException is still an mystery.
>> It should never happen even if there where broken plugins and things.
>> There is a version-mechanism that can be used to specify that
>> a plugin requires a specific version of osmosis.
> 
> 
> We'll need to make this more robust.  It would be good enough to isolate
> the
> problem to a single plugin so the user knows where the problem lies.
> Hopefully this isn't impossible with JPF.

That's the problem.
What what I have reat and seen in the stack-trace:
a) no plugin was present. It was giving an empty array of plugin-locations
to the registerPlugins()-method.
   My on-line-patch should avoid calling the jpf-code at all in this case
to
   avoid the issue altogether.
b) the NullPointerException is inside jpf.jar and lookin at the source-code
in that line
   there can be no NullPointerException without already having encountered
one.
c) Up to now it can only be reproduced on Jochen's 64bit-machine and the
same
   code works fine everywhere else.
So, how can we debug something we cannot reproduce?

Jochen: Care to run the problematic command-line with a debugger attached
to find out what is actually null here? I compiled the jpf.jar myself from
the latest stable code to make sure it includes debug-symbols just for such
cases.

Marcus