Avoid collisions in CPDF_IndirectObjectHolder::AddIndirectObject()

Avoid collisions in CPDF_IndirectObjectHolder::AddIndirectObject()

The change at 5b7c9bb differed from the original code in
that a pre-existing object would now be freed, which showed
that a collision could be possible if m_LastObjNum overflowed. 

BUG=649206
Committed: https://pdfium.googlesource.com/pdfium/+/7757143c12c972c9b0813b5b53cecba33544e7f8

[Tom Sepez, 2016-09-22 23:55:59]

The CQ bit was checked by tsepez@chromium.org to run a CQ dry run

[commit-bot: I haz the power, 2016-09-22 23:56:03]

Dry run: CQ is trying da patch. Follow status at
 
https://chromium-cq-status.appspot.com/v2/patch-status/codereview.chromium.or...

[Tom Sepez, 2016-09-22 23:56:34]

Description was changed from

==========
Preserve old object in CPDF_IndirectObjectHolder::AddIndirectObject()

The change at 5b7c9bb differed from the original code in
that a pre-existing object would now be freed. Leak it for
now until we find what mandates this behaviour.
==========

to

==========
Preserve old object in CPDF_IndirectObjectHolder::AddIndirectObject()

The change at 5b7c9bb differed from the original code in
that a pre-existing object would now be freed. Leak it for
now until we find what mandates this behaviour.

BUG=649209
==========

[Tom Sepez, 2016-09-22 23:56:35]

tsepez@chromium.org changed reviewers:
+ thestig@chromium.org

[Tom Sepez, 2016-09-22 23:57:09]

Lei, quick review.

[Tom Sepez, 2016-09-22 23:57:58]

Description was changed from

==========
Preserve old object in CPDF_IndirectObjectHolder::AddIndirectObject()

The change at 5b7c9bb differed from the original code in
that a pre-existing object would now be freed. Leak it for
now until we find what mandates this behaviour.

BUG=649209
==========

to

==========
Preserve old object in CPDF_IndirectObjectHolder::AddIndirectObject()

The change at 5b7c9bb differed from the original code in
that a pre-existing object would now be freed. Leak it for
now until we find what mandates this behaviour.

BUG=649206
==========

[commit-bot: I haz the power, 2016-09-23 00:06:36]

The CQ bit was unchecked by commit-bot@chromium.org

[commit-bot: I haz the power, 2016-09-23 00:06:39]

Dry run: This issue passed the CQ dry run.

[Tom Sepez, 2016-09-23 00:34:18]

Description was changed from

==========
Preserve old object in CPDF_IndirectObjectHolder::AddIndirectObject()

The change at 5b7c9bb differed from the original code in
that a pre-existing object would now be freed. Leak it for
now until we find what mandates this behaviour.

BUG=649206
==========

to

==========
Avoid collisions in CPDF_IndirectObjectHolder::AddIndirectObject()

The change at 5b7c9bb differed from the original code in
that a pre-existing object would now be freed, which showed
that a collision could be possible if m_LastObjNum overflowed. 

BUG=649206
==========

[Tom Sepez, 2016-09-23 00:34:27]

The CQ bit was checked by tsepez@chromium.org to run a CQ dry run

[commit-bot: I haz the power, 2016-09-23 00:34:34]

Dry run: CQ is trying da patch. Follow status at
 
https://chromium-cq-status.appspot.com/v2/patch-status/codereview.chromium.or...

[commit-bot: I haz the power, 2016-09-23 00:38:22]

The CQ bit was unchecked by commit-bot@chromium.org

[commit-bot: I haz the power, 2016-09-23 00:38:23]

Dry run: Try jobs failed on following builders:
  win on master.tryserver.client.pdfium (JOB_FAILED,
https://build.chromium.org/p/tryserver.client.pdfium/builders/win/builds/2174)

[Tom Sepez, 2016-09-23 16:06:29]

tsepez@chromium.org changed reviewers:
+ npm@chromium.org

[Tom Sepez, 2016-09-23 16:06:47]

+npm in case Lei is occupied ..

[Lei Zhang, 2016-09-23 17:19:07]

lgtm

[Tom Sepez, 2016-09-23 18:01:46]

The CQ bit was checked by tsepez@chromium.org

[commit-bot: I haz the power, 2016-09-23 18:01:55]

CQ is trying da patch. Follow status at
 
https://chromium-cq-status.appspot.com/v2/patch-status/codereview.chromium.or...

[commit-bot: I haz the power, 2016-09-23 18:13:24]

The CQ bit was unchecked by commit-bot@chromium.org

[commit-bot: I haz the power, 2016-09-23 18:13:25]

Try jobs failed on following builders:
  win_xfa_clang on master.tryserver.client.pdfium (JOB_FAILED,
https://build.chromium.org/p/tryserver.client.pdfium/builders/win_xfa_clang/b...)

[Tom Sepez, 2016-09-23 19:10:09]

Argh, introduced diffs by being clever.  Restore exact old behaviour.

[Tom Sepez, 2016-09-23 19:10:24]

The CQ bit was checked by tsepez@chromium.org

[Tom Sepez, 2016-09-23 19:10:25]

The patchset sent to the CQ was uploaded after l-g-t-m from thestig@chromium.org
Link to the patchset: https://codereview.chromium.org/2361303002/#ps60001
(title: "back to old solution.")

[commit-bot: I haz the power, 2016-09-23 19:10:36]

CQ is trying da patch. Follow status at
 
https://chromium-cq-status.appspot.com/v2/patch-status/codereview.chromium.or...

[commit-bot: I haz the power, 2016-09-23 19:21:12]

Description was changed from

==========
Avoid collisions in CPDF_IndirectObjectHolder::AddIndirectObject()

The change at 5b7c9bb differed from the original code in
that a pre-existing object would now be freed, which showed
that a collision could be possible if m_LastObjNum overflowed. 

BUG=649206
==========

to

==========
Avoid collisions in CPDF_IndirectObjectHolder::AddIndirectObject()

The change at 5b7c9bb differed from the original code in
that a pre-existing object would now be freed, which showed
that a collision could be possible if m_LastObjNum overflowed. 

BUG=649206

Committed:
https://pdfium.googlesource.com/pdfium/+/7757143c12c972c9b0813b5b53cecba33544...
==========

[commit-bot: I haz the power, 2016-09-23 19:21:13]

Committed patchset #4 (id:60001) as
https://pdfium.googlesource.com/pdfium/+/7757143c12c972c9b0813b5b53cecba33544...

[Lei Zhang, 2016-09-23 19:29:48]

whomp whomp