Reland of lax a couple checks to allow certain non-standard PDF files. (patchset #1 id:1 of https://codereview.chromium.org/1946693002/ )

Reason for revert:
The culprit was found and confirmed, not this one.

Original issue's description:
> Revert of Relax a couple checks to allow certain non-standard PDF files. (patchset #1 id:1 of https://codereview.chromium.org/1926823002/ )
>
> Reason for revert:
> Speculatively revert due to high volume of crashes on Chromium.
>
> Original issue's description:
> > Relax a couple checks to allow certain non-standard PDF files.
> >
> > Some non-standard PDF files misuse the size of cross reference table,
> > and reuse some object number which the old one is still in use. PDFium
> > can relax the reusing of xref objects only since it is not referred in
> > the pdf document. When the size of cross reference table is larger
> > than defined, PDFium will try to continue other than abort.
> >
> > BUG=chromium:596947
> >
> > Committed: https://pdfium.googlesource.com/pdfium/+/cd1e9ff4f432cbc29ed279e6891fb7ddc2ea3734
>
> TBR=thestig@chromium.org,dsinclair@chromium.org
> # Not skipping CQ checks because original CL landed more than 1 days ago.
> BUG=chromium:596947
>
> Committed: https://pdfium.googlesource.com/pdfium/+/5fc4f31285c3a88fc157fd2d9b9cf2eb5c7cabed

TBR=thestig@chromium.org,dsinclair@chromium.org
# Skipping CQ checks because original CL landed less than 1 days ago.
NOPRESUBMIT=true
NOTREECHECKS=true
NOTRY=true
BUG=chromium:596947

Review-Url: https://codereview.chromium.org/1947983002

1 files changed, 16 insertions, 0 deletions

diff --git a/core/fpdfapi/fpdf_parser/cpdf_parser_embeddertest.cpp b/core/fpdfapi/fpdf_parser/cpdf_parser_embeddertest.cpp
index 042b221554..d070bd6a4c 100644
--- a/core/fpdfapi/fpdf_parser/cpdf_parser_embeddertest.cpp
+++ b/core/fpdfapi/fpdf_parser/cpdf_parser_embeddertest.cpp
@@ -54,3 +54,19 @@ TEST_F(CPDFParserEmbeddertest, Bug_602650) {
   FPDFText_ClosePage(text_page);
   UnloadPage(page);
 }
+
+TEST_F(CPDFParserEmbeddertest, Bug_596947) {
+  // Test the case that the size of cross reference entries doesn't match with
+  // what is defined, and a certain case of reuse object number for cross
+  // reference object.
+  EXPECT_TRUE(OpenDocument("bug_596947.pdf"));
+  FPDF_PAGE page = LoadPage(0);
+  EXPECT_NE(nullptr, page);
+  FPDF_TEXTPAGE text_page = FPDFText_LoadPage(page);
+  EXPECT_NE(nullptr, text_page);
+  // The page should not be blank.
+  EXPECT_LT(0, FPDFText_CountChars(text_page));
+
+  FPDFText_ClosePage(text_page);
+  UnloadPage(page);
+}