tree 1c90d4db4bad01fd554a4dd20628ac2dc9503d90
parent 48f923f8a9a88db2fca4d5cbaca60f7272aa6b76
author Lei Zhang <thestig@chromium.org> 1715705239 +0000
committer Tom Sepez <tsepez@chromium.org> 1715705239 +0000

M124: Fix yet another edited PDF that regressed

Rework CPDF_Parser cross reference table loading code yet again to make
the bug_335309995.pdf pixel test pass, while not causing any other tests
to regress.

For starters, get rid of the code where cross reference stream entries
do not overwrite existing entries. That logic forced cross reference
streams to be parsed in reverse order, which is awkward when the cross
reference tables are parsed in the normal order.

With that sorted out, LoadAllSecondaryCrossRefStreams() and
LoadAllCrossRefStreams() are no longer useful, as they parsed cross
reference data in reverse order. Instead, let LoadAllCrossRefTables()
take over their duties with more cross reference stream parsing logic.
As such, rename it to LoadAllCrossRefTablesAndStreams().

Then flip the ordering when reading cross reference data updates, so
tables have precedence over streams, per PDF spec.

Apply the same change to CPDF_Parser::LoadLinearizedAllCrossRefTable()
as well.

Bug: 330885080, 335309995, 336517370
Change-Id: I1f44cee17626104f78aaceca403f6bf1a3a09802
Reviewed-on: https://pdfium-review.googlesource.com/c/pdfium/+/118571
Reviewed-by: Thomas Sepez <tsepez@google.com>
Reviewed-by: Tom Sepez <tsepez@chromium.org>
Commit-Queue: Lei Zhang <thestig@chromium.org>
(cherry picked from commit 02ff1756cfb2c2b8d900d98efd54a4d726b805b6)
Reviewed-on: https://pdfium-review.googlesource.com/c/pdfium/+/119055