Prevent infinite looping in CPDF_Parser::LoadAllCrossRefV5().

fpdfsdk/src/fpdfview_embeddertest.cpp

Index: fpdfsdk/src/fpdfview_embeddertest.cpp
diff --git a/fpdfsdk/src/fpdfview_embeddertest.cpp b/fpdfsdk/src/fpdfview_embeddertest.cpp
index 35da9b6caf922816e8867cd7a430bd3c85585a4f..3be96e7aef278b412c408d17497db692f3dd4833 100644
--- a/fpdfsdk/src/fpdfview_embeddertest.cpp
+++ b/fpdfsdk/src/fpdfview_embeddertest.cpp
@@ -199,3 +199,8 @@ TEST_F(FPDFViewEmbeddertest, Crasher_454695) {
   // Document is damanged and can't be opened.
   EXPECT_FALSE(OpenDocument("bug_454695.pdf"));
 }
+
+// The following tests pass if the document opens without infinite looping.
+TEST_F(FPDFViewEmbeddertest, Hang_298) {
+  EXPECT_FALSE(OpenDocument("bug_298.pdf"));
+}