Reset property so it doesn't leak to other models

[mfn]

If the FileValidation is used in multiple models which are validated within a single request, since Behaviours are effectively singletons, their internal state leaks over to the next model.

This prevents $_tmpFile still being set for the next model; otherwise this file would be tried to be deleted again in the next model validation which does not exist anymore.

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We observed this problem when saving two models successively which both used FileValidation. Only in the first model a file was attached, the second model had no file (but validation rules) and these were executed. The led to the leakage of _tempFile and this a duplicate deletion attempt which failed.

Implementation detail: although the Transit package uses the following code:

    public function delete() {
        $this->reset();

        return @unlink($this->_path);
    }

which actually prevents warnings being generated, this can change with custom error handlers and thus still generate warnings depending on the environment.

[milesj]

Nice catch! Thanks for the fix.

[mfn]

@milesj there have been a few fixes already, would you mind rolling a new release? thanks!

[milesj]

Thanks for reminding me. Will get to it later today.