Fix buffer management issues in CFX_SAXReader.

Re-write to use std::vectors rather than self-managed buffers.
Includes test case that breaks before patch.

Formerly, we had two independent buffers whose position were
tracked by the same variable, assuming that only one was
being written to at a given time.  This is a bad idea because
it's easy to forget to zero the index when switching buffers,
and start indexing into one using previously computed offsets
from the other.

Additionally, there were cases where the location of a partial
entity wasn't discarded when switching states thus clearing the
buffer tracking said entity.

Bug: 711459
Change-Id: I008f69517d4319a5fe8abda8d54c5b9975551697
Reviewed-on: https://pdfium-review.googlesource.com/4230
Reviewed-by: Lei Zhang <thestig@chromium.org>
Commit-Queue: Tom Sepez <tsepez@chromium.org>

0 files changed, 0 insertions, 0 deletions