Giving a Property as workersrcs to MultipleFileUpload breaks

[benallard]

This issue was introduced by 4173dac.

I give a Property parameter to MultipleFileUploads, the property resolves to a list.

Due to the mentioned commit, The value is now a list of list, and this breaks.

2017-05-02 12:55:50+0200 [-] MultipleFileUpload started, from worker [[u'build/filename']] to master '/home/buildsystem/master/public_html/destination'
2017-05-02 12:55:50+0200 [-] BuildStep.failed; traceback follows
        Traceback (most recent call last):
          File "/home/buildsystem/bb-master/local/lib/python2.7/site-packages/twisted/internet/defer.py", line 1357, in gotResult
            _inlineCallbacks(r, g, deferred)
          File "/home/buildsystem/bb-master/local/lib/python2.7/site-packages/twisted/internet/defer.py", line 1301, in _inlineCallbacks
            result = g.send(result)
          File "/home/buildsystem/bb-master/local/lib/python2.7/site-packages/buildbot/process/buildstep.py", line 547, in startStep
            self.results = yield self.run()
          File "/home/buildsystem/bb-master/local/lib/python2.7/site-packages/twisted/internet/defer.py", line 1447, in unwindGenerator
            return _inlineCallbacks(None, gen, Deferred())
        --- <exception caught here> ---
          File "/home/buildsystem/bb-master/local/lib/python2.7/site-packages/twisted/internet/defer.py", line 1301, in _inlineCallbacks
            result = g.send(result)
          File "/home/buildsystem/bb-master/local/lib/python2.7/site-packages/buildbot/process/buildstep.py", line 677, in run
            results = yield self._start_deferred
        exceptions.AttributeError: 'list' object has no attribute 'rfind'

[benallard]

@noc0lour

[benallard]

I'd be in favor of reverting the said commit. Why should MultipleFileUploads be able to magically behave as if it weren't Multiple ?

[tardyp]

I think we can easily add
and not IRenderable.providedBy(workersrc))
like in https://github.com/buildbot/buildbot/blob/master/master/buildbot/steps/cmake.py#L52

The commit is part of the more general and useful PR:

transfer: add glob parameter to MultipleFileUpload #2635

[benallard]

If we do that the given renderable will have to render as a list. Bypassing the magical part (i.e. a property that render as a string will not work). IMHO, glob support (granted, useful) doesn't require the type of the parameter to be a string. Additionally, it's not even documented that a string can be given as parameter. Lastly, even the tests don't exerce the combination glob + string.

[tardyp]

@benallard make sense. @noc0lour please defend your design :)

[noc0lour]

I don't see why MultipleFileUpload shouldn't be able to upload just one file. e.g. your renderable returns only one item or None.
Probably this check is better placed start().
Can you add the test? I'll submit a PR with a proposed fix which should resolve your issue.