Fix loading page using hint tables.

core/fpdfapi/parser/cpdf_document_unittest.cpp

+// Copyright 2016 PDFium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include "core/fpdfapi/parser/cpdf_document.h"
+
+#include <memory>
+
+#include "core/fpdfapi/parser/cpdf_parser.h"
+#include "core/fpdfapi/parser/cpdf_dictionary.h"
+#include "core/fxcrt/fx_memory.h"
+#include "testing/gtest/include/gtest/gtest.h"
+
+namespace {
+
+using ScopedDictionary =
+    std::unique_ptr<CPDF_Dictionary, ReleaseDeleter<CPDF_Dictionary>>;
+
+}  // namespace
+
+TEST(cpdf_document, UseCachedPageObjNumIfHaveNotPagesDict) {
+  // ObjNum can be added in CPDF_DataAvail::IsPageAvail, and PagesDict
+  // can be not exists in this case.
+  // (case, when hint table is used to page check in CPDF_DataAvail).
+  CPDF_Document document(std::make_unique<CPDF_Parser>());
+  ScopedDictionary dict(new CPDF_Dictionary());
+  const int page_count = 100;
+  dict->SetIntegerFor("N", page_count);
+  document.LoadLinearizedDoc(dict.get());
+  ASSERT_EQ(page_count, document.GetPageCount());
+  CPDF_Object* page_stub = new CPDF_Dictionary();
+  const uint32_t obj_num = document.AddIndirectObject(page_stub);
+  const int test_page_num = 33;
+
+  EXPECT_FALSE(document.IsPageLoaded(test_page_num));
+  EXPECT_EQ(nullptr, document.GetPage(test_page_num));
+
+  document.SetPageObjNum(test_page_num, obj_num);
+  EXPECT_TRUE(document.IsPageLoaded(test_page_num));
+  EXPECT_EQ(page_stub, document.GetPage(test_page_num));
+}