Resolve compilation error with G++ 4.9.

core/src/fpdfapi/fpdf_parser/fpdf_parser_parser.cpp

 // Copyright 2014 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.
  
 // Original code copyright 2014 Foxit Software Inc. http://www.foxitsoftware.com
 
 #include "../../../include/fpdfapi/fpdf_parser.h"
 #include "../../../include/fpdfapi/fpdf_module.h"
 #include "../../../include/fpdfapi/fpdf_page.h"
 #include "../../../../third_party/numerics/safe_math.h"
@@ skipping 2167 matching lines @@
             if (key == FX_BSTRC("endobj")) {
                 dwDictSize = m_Pos - 6 - saveDictOffset;
                 m_Pos = SavedPos;
                 break;
             }
             if (key[0] != '/') {
                 continue;
             }
             nKeys ++;
             key = PDF_NameDecode(key);
+            if (key.IsEmpty()) {

[jun_fang, 2014/10/29 18:21:50]

IsEmpty is checked at Ln2168. If key is not empty before Ln2187, it shall not be
empty after the function of PDF_NameDecode. Do you think it's necessary to add
another check here?

+                if (pDict)
+                    pDict->Release();
+                return NULL;
+            }
             if (key == FX_BSTRC("/Contents")) {
                 dwSignValuePos = m_Pos;
             }
             CPDF_Object* pObj = GetObject(pObjList, objnum, gennum, level + 1);
             if (pObj == NULL) {
                 continue;
             }
             if (key.GetLength() == 1) {

[Tom Sepez, 2014/10/29 18:49:41]

Maybe instead we just check here for key.GetLength() == 0?

[jun_fang, 2014/10/29 18:58:29]

I am checking the code here. I think that the current logic may not be correct.
It's easy to understand that we add to use addvalue when nKeys >= 32. When nKeys
< 32, we only needs to call SetAt(). For example, assume key.GetLength() = 1 and
nKeys = 33 here. I think Addvalue shall be called rather SetAt. So my suggestion
for change is :

if (key.GetLength() >= 1) {
    if (nKeys < 32) {
       pDict->SetAt(CFX_ByteStringC(((FX_LPCSTR)key) + 1, key.GetLength() - 1),
pObj);
     } else {
       pDict->AddValue(CFX_ByteStringC(((FX_LPCSTR)key) + 1, key.GetLength() -
1), pObj);
}

                 pDict->SetAt(CFX_ByteStringC(((FX_LPCSTR)key) + 1, key.GetLength() - 1), pObj);
             } else {
                 if (nKeys < 32) {
                     pDict->SetAt(CFX_ByteStringC(((FX_LPCSTR)key) + 1, key.GetLength() - 1), pObj);
                 } else {
                     pDict->AddValue(CFX_ByteStringC(((FX_LPCSTR)key) + 1, key.GetLength() - 1), pObj);
                 }
             }
         }
         if (IsSignatureDict(pDict)) {
@@ skipping 2227 matching lines @@
 {
     FX_INT32 iSize = m_childNode.GetSize();
     for (FX_INT32 i = 0; i < iSize; ++i) {
         CPDF_PageNode *pNode = (CPDF_PageNode*)m_childNode[i];
         if (pNode) {
             delete pNode;
         }
     }
     m_childNode.RemoveAll();
 }