tree efb471042d8aa50faa54b5c542bfd116ad481d66
parent b5e19ba4a63668eb79081588aad5af9f4e7a0bc6
author Lei Zhang <thestig@chromium.org> 1731349918 +0000
committer Pdfium LUCI CQ <pdfium-scoped@luci-project-accounts.iam.gserviceaccount.com> 1731349918 +0000

Fix FPDFPageObj_SetIsActive() crash

When FPDFPageObj_SetIsActive() deactivates the sole page object,
FPDFPage_GenerateContent() may delete the page object's content stream.
When the page object gets reactivated, its content stream will have
unexpectedly disappeared by the time the next FPDFPage_GenerateContent()
call gets made. This leads to a CHECK() failure crash in
CPDF_PageContentManager::UpdateStream().

Fix this by adjusting CPDF_PageContentGenerator to avoid the crash.
By adding CPDF_PageContentManager::HasStreamAtIndex(),
CPDF_PageContentGenerator can now call it to see if the content stream
is gone. If it gone, call AddStream() instead of UpdateStream().

With the crash fixes, resolve a TODO and add the rest of the test case
that exercises FPDFPageObj_SetIsActive().

Bug: 378120423
Change-Id: I7523a8dac6be881ee520747f81b0730f815d3144
Reviewed-on: https://pdfium-review.googlesource.com/c/pdfium/+/125690
Reviewed-by: dan sinclair <dsinclair@google.com>
Commit-Queue: Lei Zhang <thestig@chromium.org>