Re: [PATCH] Avoid memcpy-from-NULL in apr_brigade_flatten

> Thanks for the patch, this is an interesting find. Can you say what
> bucket type was hit here - e.g. print b->type->name in gdb from inside
> apr_brigade_flatten()?

Sure thing. It's an EOS bucket.

> It looks like metadata bucket types tend to give NULL on read() so I'm
> guessing that's the case here. It would trip up other apr_brigade_*
> functions in similar ways, e.g. split_line looks wrong too. You can make
> a case that ignoring FLUSH is "safe" but it's probably undesirable, and
> trying to flatten across an EOS is almost certainly wrong.

> So I'm not sure, maybe a better/safer response is to catch metadata
> buckets and treat them as end-of-brigade or an error rather than
> zero-length data buckets. apr_brigade_split_boundary has an API
> condition for that to explicitly return APR_INCOMPLETE.

It might not be worth complicating the operation. I would think that
when someone wants to flatten a bucket brigade, they want the empty
buckets to be ignored, which is the current behavior with unoptimized
clang and gcc. You would know better than me, though :)

-Ben