BUG/MINOR: quic: Safer QUIC frame builders

Do not rely on the fact the callers of qc_build_frm() handle their
buffer passed to function the correct way (without leaving garbage).
Make qc_build_frm() update the buffer passed as argument only if
the frame it builds is well formed.

As far as I sse, there is no such callers which does not handle
carefully such buffers.

Must be backported to 2.6.
2 files changed