Revert "Simplify CPDF_PageOrganizer::UpdateReference method."

This reverts commit 35ab1bd0328a244cc2f6dcde2822c8117738b01d.

Reason for revert: Causing crashes and bad flattening.

BUG=chromium:858921,chromium:858952

Original change's description:
> Simplify CPDF_PageOrganizer::UpdateReference method.
> 
> Change-Id: I52fe66472bdc2a61d7074f77627a3ee1d5646255
> Reviewed-on: https://pdfium-review.googlesource.com/35611
> Reviewed-by: dsinclair <dsinclair@chromium.org>
> Commit-Queue: Art Snake <art-snake@yandex-team.ru>

TBR=dsinclair@chromium.org,art-snake@yandex-team.ru

Change-Id: I9a3635140867793e7109c15b64d66ec1d1a8b1f9
No-Presubmit: true
No-Tree-Checks: true
No-Try: true
Reviewed-on: https://pdfium-review.googlesource.com/36550
Reviewed-by: Lei Zhang <thestig@chromium.org>
Commit-Queue: Lei Zhang <thestig@chromium.org>

1 files changed, 47 insertions, 18 deletions

diff --git a/fpdfsdk/fpdf_ppo.cpp b/fpdfsdk/fpdf_ppo.cpp
index a35702efd9..8bbae7258d 100644
--- a/fpdfsdk/fpdf_ppo.cpp
+++ b/fpdfsdk/fpdf_ppo.cpp
@@ -20,7 +20,6 @@
 #include "core/fpdfapi/parser/cpdf_name.h"
 #include "core/fpdfapi/parser/cpdf_number.h"
 #include "core/fpdfapi/parser/cpdf_object.h"
-#include "core/fpdfapi/parser/cpdf_object_walker.h"
 #include "core/fpdfapi/parser/cpdf_reference.h"
 #include "core/fpdfapi/parser/cpdf_stream.h"
 #include "core/fpdfapi/parser/cpdf_stream_acc.h"
@@ -356,25 +355,55 @@ bool CPDF_PageOrganizer::PDFDocInit() {
 
 bool CPDF_PageOrganizer::UpdateReference(CPDF_Object* pObj,
                                          ObjectNumberMap* pObjNumberMap) {
-  for (CPDF_NonConstObjectWalker walker(pObj);
-       CPDF_Object* child = walker.GetNext();) {
-    if (walker.dictionary_key() == "Parent" ||
-        walker.dictionary_key() == "Prev" ||
-        walker.dictionary_key() == "First") {
-      walker.SkipWalkIntoCurrentObject();
-      continue;
+  switch (pObj->GetType()) {
+    case CPDF_Object::REFERENCE: {
+      CPDF_Reference* pReference = pObj->AsReference();
+      uint32_t newobjnum = GetNewObjId(pObjNumberMap, pReference);
+      if (newobjnum == 0)
+        return false;
+      pReference->SetRef(dest(), newobjnum);
+      break;
     }
-    if (!child->IsReference())
-      continue;
-
-    CPDF_Reference* ref = ToReference(child);
-
-    const uint32_t newobjnum = GetNewObjId(pObjNumberMap, ref);
-    if (newobjnum == 0)
-      return false;
-
-    ref->SetRef(dest(), newobjnum);
+    case CPDF_Object::DICTIONARY: {
+      CPDF_Dictionary* pDict = pObj->AsDictionary();
+      auto it = pDict->begin();
+      while (it != pDict->end()) {
+        const ByteString& key = it->first;
+        CPDF_Object* pNextObj = it->second.get();
+        ++it;
+        if (key == "Parent" || key == "Prev" || key == "First")
+          continue;
+        if (!pNextObj)
+          return false;
+        if (!UpdateReference(pNextObj, pObjNumberMap))
+          pDict->RemoveFor(key);
+      }
+      break;
+    }
+    case CPDF_Object::ARRAY: {
+      CPDF_Array* pArray = pObj->AsArray();
+      for (size_t i = 0; i < pArray->GetCount(); ++i) {
+        CPDF_Object* pNextObj = pArray->GetObjectAt(i);
+        if (!pNextObj)
+          return false;
+        if (!UpdateReference(pNextObj, pObjNumberMap))
+          return false;
+      }
+      break;
+    }
+    case CPDF_Object::STREAM: {
+      CPDF_Stream* pStream = pObj->AsStream();
+      CPDF_Dictionary* pDict = pStream->GetDict();
+      if (!pDict)
+        return false;
+      if (!UpdateReference(pDict, pObjNumberMap))
+        return false;
+      break;
+    }
+    default:
+      break;
   }
+
   return true;
 }