Remove "this==NULL" and adjust corresponding callers

BUG=
R=thakis@chromium.org

Review URL: https://codereview.chromium.org/361553002

7 files changed, 151 insertions, 191 deletions

diff --git a/core/src/fpdfapi/fpdf_parser/fpdf_parser_decode.cpp b/core/src/fpdfapi/fpdf_parser/fpdf_parser_decode.cpp
index 6b2483eda7..5854d71344 100644
--- a/core/src/fpdfapi/fpdf_parser/fpdf_parser_decode.cpp
+++ b/core/src/fpdfapi/fpdf_parser/fpdf_parser_decode.cpp
@@ -45,7 +45,7 @@ FX_DWORD _A85Decode(const FX_BYTE* src_buf, FX_DWORD src_size, FX_LPBYTE& dest_b
         return (FX_DWORD) - 1;
     }
     int state = 0;
-	FX_UINT32 res = 0;
+    FX_UINT32 res = 0;
     pos = dest_size = 0;
     while (pos < src_size) {
         FX_BYTE ch = src_buf[pos++];
@@ -281,11 +281,11 @@ FX_BOOL PDF_DataDecode(FX_LPCBYTE src_buf, FX_DWORD src_size, const CPDF_Diction
                        CPDF_Dictionary*& pImageParms, FX_DWORD last_estimated_size, FX_BOOL bImageAcc)
 
 {
-    CPDF_Object* pDecoder = pDict->GetElementValue(FX_BSTRC("Filter"));
+    CPDF_Object* pDecoder = pDict ? pDict->GetElementValue(FX_BSTRC("Filter")) : NULL;
     if (pDecoder == NULL || (pDecoder->GetType() != PDFOBJ_ARRAY && pDecoder->GetType() != PDFOBJ_NAME)) {
         return FALSE;
     }
-    CPDF_Object* pParams = pDict->GetElementValue(FX_BSTRC("DecodeParms"));
+    CPDF_Object* pParams = pDict ? pDict->GetElementValue(FX_BSTRC("DecodeParms")) : NULL;
     CFX_ByteStringArray DecoderList;
     CFX_PtrArray ParamList;
     if (pDecoder->GetType() == PDFOBJ_ARRAY) {
@@ -304,7 +304,7 @@ FX_BOOL PDF_DataDecode(FX_LPCBYTE src_buf, FX_DWORD src_size, const CPDF_Diction
         }
     } else {
         DecoderList.Add(pDecoder->GetConstString());
-        ParamList.Add(pParams->GetDict());
+        ParamList.Add(pParams ? pParams->GetDict() : NULL);
     }
     FX_LPBYTE last_buf = (FX_LPBYTE)src_buf;
     FX_DWORD last_size = src_size;
diff --git a/core/src/fpdfapi/fpdf_parser/fpdf_parser_document.cpp b/core/src/fpdfapi/fpdf_parser/fpdf_parser_document.cpp
index a4982040bf..cd100a80cc 100644
--- a/core/src/fpdfapi/fpdf_parser/fpdf_parser_document.cpp
+++ b/core/src/fpdfapi/fpdf_parser/fpdf_parser_document.cpp
@@ -61,11 +61,13 @@ void CPDF_Document::LoadAsynDoc(CPDF_Dictionary *pLinearized)
 {
     m_bLinearized = TRUE;
     m_LastObjNum = m_pParser->GetLastObjNum();
-    m_pRootDict = GetIndirectObject(m_pParser->GetRootObjNum())->GetDict();
+    CPDF_Object* indirectObj = GetIndirectObject(m_pParser->GetRootObjNum());
+    m_pRootDict = indirectObj ? indirectObj->GetDict() : NULL;
     if (m_pRootDict == NULL) {
         return;
     }
-    m_pInfoDict = GetIndirectObject(m_pParser->GetInfoObjNum())->GetDict();
+    indirectObj = GetIndirectObject(m_pParser->GetInfoObjNum());
+    m_pInfoDict = indirectObj ? indirectObj->GetDict() : NULL;
     CPDF_Array* pIDArray = m_pParser->GetIDArray();
     if (pIDArray) {
         m_ID1 = pIDArray->GetString(0);
@@ -336,7 +338,7 @@ FX_BOOL CPDF_Document::IsContentUsedElsewhere(FX_DWORD objnum, CPDF_Dictionary*
         if (pPageDict == pThisPageDict) {
             continue;
         }
-        CPDF_Object* pContents = pPageDict->GetElement(FX_BSTRC("Contents"));
+        CPDF_Object* pContents = pPageDict ? pPageDict->GetElement(FX_BSTRC("Contents")) : NULL;
         if (pContents == NULL) {
             continue;
         }
diff --git a/core/src/fpdfapi/fpdf_parser/fpdf_parser_encrypt.cpp b/core/src/fpdfapi/fpdf_parser/fpdf_parser_encrypt.cpp
index fadcd38b1b..e09bbbbb2e 100644
--- a/core/src/fpdfapi/fpdf_parser/fpdf_parser_encrypt.cpp
+++ b/core/src/fpdfapi/fpdf_parser/fpdf_parser_encrypt.cpp
@@ -292,11 +292,11 @@ void Revision6_Hash(FX_LPCBYTE password, FX_DWORD size, FX_LPCBYTE salt, FX_LPCB
 FX_BOOL CPDF_StandardSecurityHandler::AES256_CheckPassword(FX_LPCBYTE password, FX_DWORD size,
         FX_BOOL bOwner, FX_LPBYTE key)
 {
-    CFX_ByteString okey = m_pEncryptDict->GetString(FX_BSTRC("O"));
+    CFX_ByteString okey = m_pEncryptDict ? m_pEncryptDict->GetString(FX_BSTRC("O")) : CFX_ByteString();
     if (okey.GetLength() < 48) {
         return FALSE;
     }
-    CFX_ByteString ukey = m_pEncryptDict->GetString(FX_BSTRC("U"));
+    CFX_ByteString ukey = m_pEncryptDict ? m_pEncryptDict->GetString(FX_BSTRC("U")) : CFX_ByteString();
     if (ukey.GetLength() < 48) {
         return FALSE;
     }
@@ -331,7 +331,7 @@ FX_BOOL CPDF_StandardSecurityHandler::AES256_CheckPassword(FX_LPCBYTE password,
         }
         CRYPT_SHA256Finish(sha, digest);
     }
-    CFX_ByteString ekey = m_pEncryptDict->GetString(bOwner ? FX_BSTRC("OE") : FX_BSTRC("UE"));
+    CFX_ByteString ekey = m_pEncryptDict ? m_pEncryptDict->GetString(bOwner ? FX_BSTRC("OE") : FX_BSTRC("UE")) : CFX_ByteString();
     if (ekey.GetLength() < 32) {
         return FALSE;
     }
@@ -391,7 +391,7 @@ FX_BOOL CPDF_StandardSecurityHandler::CheckUserPassword(FX_LPCBYTE password, FX_
 {
     CalcEncryptKey(m_pEncryptDict, password, pass_size, key, key_len, bIgnoreEncryptMeta,
                    m_pParser->GetIDArray());
-    CFX_ByteString ukey = m_pEncryptDict->GetString(FX_BSTRC("U"));
+    CFX_ByteString ukey = m_pEncryptDict ? m_pEncryptDict->GetString(FX_BSTRC("U")) : CFX_ByteString();
     if (ukey.GetLength() < 16) {
         return FALSE;
     }
diff --git a/core/src/fpdfapi/fpdf_parser/fpdf_parser_fdf.cpp b/core/src/fpdfapi/fpdf_parser/fpdf_parser_fdf.cpp
index 36cc9db754..dd4eeddc17 100644
--- a/core/src/fpdfapi/fpdf_parser/fpdf_parser_fdf.cpp
+++ b/core/src/fpdfapi/fpdf_parser/fpdf_parser_fdf.cpp
@@ -111,7 +111,8 @@ FX_BOOL CFDF_Document::WriteBuf(CFX_ByteTextBuf& buf) const
 }
 CFX_WideString CFDF_Document::GetWin32Path() const
 {
-    CPDF_Object* pFileSpec = m_pRootDict->GetDict(FX_BSTRC("FDF"))->GetElementValue(FX_BSTRC("F"));
+    CPDF_Dictionary* pDict = m_pRootDict ? m_pRootDict->GetDict(FX_BSTRC("FDF")) : NULL;
+    CPDF_Object* pFileSpec = pDict ? pDict->GetElementValue(FX_BSTRC("F")) : NULL;
     if (pFileSpec == NULL) {
         return CFX_WideString();
     }
@@ -203,7 +204,10 @@ CFX_WideString	FPDF_FileSpec_GetWin32Path(const CPDF_Object* pFileSpec)
         if (wsFileName.IsEmpty() && pDict->KeyExist(FX_BSTRC("DOS"))) {
             wsFileName = CFX_WideString::FromLocal(pDict->GetString(FX_BSTRC("DOS")));
         }
-    } else {
+    }
+    else if (!pFileSpec)
+        wsFileName = CFX_WideString();
+    else {
         wsFileName = CFX_WideString::FromLocal(pFileSpec->GetString());
     }
     if (wsFileName[0] != '/') {
diff --git a/core/src/fpdfapi/fpdf_parser/fpdf_parser_filters.cpp b/core/src/fpdfapi/fpdf_parser/fpdf_parser_filters.cpp
index 1e4e1570df..610fb39781 100644
--- a/core/src/fpdfapi/fpdf_parser/fpdf_parser_filters.cpp
+++ b/core/src/fpdfapi/fpdf_parser/fpdf_parser_filters.cpp
@@ -76,11 +76,11 @@ CFX_DataFilter* FPDF_CreateFilter(FX_BSTR name, const CPDF_Dictionary* pParam, i
         case FXBSTR_ID('L', 'Z', 'W', 0): {
                 CFX_DataFilter* pFilter;
                 if (id == FXBSTR_ID('L', 'Z', 'W', 'D') || id == FXBSTR_ID('L', 'Z', 'W', 0)) {
-                    pFilter = FX_NEW CPDF_LzwFilter(pParam->GetInteger("EarlyChange", 1));
+                    pFilter = FX_NEW CPDF_LzwFilter(pParam ? pParam->GetInteger("EarlyChange", 1) : 1);
                 } else {
                     pFilter = FX_NEW CPDF_FlateFilter;
                 }
-                if (pParam->GetInteger("Predictor", 1) > 1) {
+                if ((pParam ? pParam->GetInteger("Predictor", 1) : 1) > 1) {
                     CFX_DataFilter* pPredictor = FX_NEW CPDF_PredictorFilter(pParam->GetInteger(FX_BSTRC("Predictor"), 1),
                                                  pParam->GetInteger(FX_BSTRC("Colors"), 1), pParam->GetInteger(FX_BSTRC("BitsPerComponent"), 8),
                                                  pParam->GetInteger(FX_BSTRC("Columns"), 1));
diff --git a/core/src/fpdfapi/fpdf_parser/fpdf_parser_objects.cpp b/core/src/fpdfapi/fpdf_parser/fpdf_parser_objects.cpp
index bd8b157bfa..6c93bcb39f 100644
--- a/core/src/fpdfapi/fpdf_parser/fpdf_parser_objects.cpp
+++ b/core/src/fpdfapi/fpdf_parser/fpdf_parser_objects.cpp
@@ -7,9 +7,6 @@
 #include "../../../include/fpdfapi/fpdf_parser.h"
 void CPDF_Object::Release()
 {
-    if (this == NULL) {
-        return;
-    }
     if (m_ObjNum) {
         return;
     }
@@ -39,9 +36,6 @@ void CPDF_Object::Destroy()
 }
 CFX_ByteString CPDF_Object::GetString() const
 {
-    if (this == NULL) {
-        return CFX_ByteString();
-    }
     switch (m_Type) {
         case PDFOBJ_BOOLEAN:
             return ((CPDF_Boolean*)this)->m_bValue ? "true" : "false";
@@ -67,9 +61,6 @@ CFX_ByteString CPDF_Object::GetString() const
 }
 CFX_ByteStringC CPDF_Object::GetConstString() const
 {
-    if (this == NULL) {
-        return CFX_ByteStringC();
-    }
     switch (m_Type) {
         case PDFOBJ_STRING:
             return CFX_ByteStringC((FX_LPCBYTE)((CPDF_String*)this)->m_String, ((CPDF_String*)this)->m_String.GetLength());
@@ -91,9 +82,6 @@ CFX_ByteStringC CPDF_Object::GetConstString() const
 }
 FX_FLOAT CPDF_Object::GetNumber() const
 {
-    if (this == NULL) {
-        return 0;
-    }
     switch (m_Type) {
         case PDFOBJ_NUMBER:
             return ((CPDF_Number*)this)->GetNumber();
@@ -117,9 +105,6 @@ FX_FLOAT CPDF_Object::GetNumber16() const
 }
 int CPDF_Object::GetInteger() const
 {
-    if (this == NULL) {
-        return 0;
-    }
     switch (m_Type) {
         case PDFOBJ_BOOLEAN:
             return ((CPDF_Boolean*)this)->m_bValue;
@@ -143,9 +128,6 @@ int CPDF_Object::GetInteger() const
 }
 CPDF_Dictionary* CPDF_Object::GetDict() const
 {
-    if (this == NULL) {
-        return NULL;
-    }
     switch (m_Type) {
         case PDFOBJ_DICTIONARY:
             return (CPDF_Dictionary*)this;
@@ -167,13 +149,10 @@ CPDF_Dictionary* CPDF_Object::GetDict() const
 }
 CPDF_Array* CPDF_Object::GetArray() const
 {
-    if (this == NULL) {
-        return NULL;
-    }
-    if (m_Type == PDFOBJ_ARRAY) {
+    if (m_Type == PDFOBJ_ARRAY) 
         return (CPDF_Array*)this;
-    }
-    return NULL;
+    else
+        return NULL;
 }
 void CPDF_Object::SetString(const CFX_ByteString& str)
 {
@@ -207,11 +186,11 @@ FX_BOOL CPDF_Object::IsIdentical(CPDF_Object* pOther) const
     if (this == pOther) {
         return TRUE;
     }
-    if (this == NULL || pOther == NULL) {
+    if (pOther == NULL) {
         return FALSE;
     }
     if (pOther->m_Type != m_Type) {
-        if (m_Type == PDFOBJ_REFERENCE) {
+        if (m_Type == PDFOBJ_REFERENCE && GetDirect()) {
             return GetDirect()->IsIdentical(pOther);
         } else if (pOther->m_Type == PDFOBJ_REFERENCE) {
             return IsIdentical(pOther->GetDirect());
@@ -242,9 +221,6 @@ FX_BOOL CPDF_Object::IsIdentical(CPDF_Object* pOther) const
 }
 CPDF_Object* CPDF_Object::GetDirect() const
 {
-    if (this == NULL) {
-        return NULL;
-    }
     if (m_Type != PDFOBJ_REFERENCE) {
         return (CPDF_Object*)this;
     }
@@ -261,9 +237,6 @@ CPDF_Object* CPDF_Object::Clone(FX_BOOL bDirect) const
 }
 CPDF_Object* CPDF_Object::CloneInternal(FX_BOOL bDirect, CFX_MapPtrToPtr* visited) const
 {
-    if (this == NULL) {
-        return NULL;
-    }
     switch (m_Type) {
         case PDFOBJ_BOOLEAN:
             return FX_NEW CPDF_Boolean(((CPDF_Boolean*)this)->m_bValue);
@@ -303,7 +276,11 @@ CPDF_Object* CPDF_Object::CloneInternal(FX_BOOL bDirect, CFX_MapPtrToPtr* visite
                 CPDF_StreamAcc acc;
                 acc.LoadAllData(pThis, TRUE);
                 FX_DWORD streamSize = acc.GetSize();
-                CPDF_Stream* pObj = FX_NEW CPDF_Stream(acc.DetachData(), streamSize, (CPDF_Dictionary*)((CPDF_Object*)pThis->GetDict())->CloneInternal(bDirect, visited));
+                CPDF_Stream* pObj;
+                if (pThis->GetDict())
+                    pObj = FX_NEW CPDF_Stream(acc.DetachData(), streamSize, (CPDF_Dictionary*)((CPDF_Object*)pThis->GetDict())->CloneInternal(bDirect, visited));
+                else
+                    pObj = FX_NEW CPDF_Stream(acc.DetachData(), streamSize, NULL);
                 return pObj;
             }
         case PDFOBJ_REFERENCE: {
@@ -311,7 +288,11 @@ CPDF_Object* CPDF_Object::CloneInternal(FX_BOOL bDirect, CFX_MapPtrToPtr* visite
                 FX_DWORD obj_num = pRef->m_RefObjNum;
                 if (bDirect && !visited->GetValueAt((void*)(FX_UINTPTR)obj_num)) {
                     visited->SetAt((void*)(FX_UINTPTR)obj_num, (void*)1);
-                    CPDF_Object* ret = pRef->GetDirect()->CloneInternal(TRUE, visited);
+                    CPDF_Object* ret;
+                    if (pRef->GetDirect())
+                        ret = pRef->GetDirect()->CloneInternal(TRUE, visited);
+                    else
+                        ret = NULL;
                     return ret;
                 } else {
                     return FX_NEW CPDF_Reference(pRef->m_pObjList, obj_num);
@@ -322,9 +303,6 @@ CPDF_Object* CPDF_Object::CloneInternal(FX_BOOL bDirect, CFX_MapPtrToPtr* visite
 }
 CPDF_Object* CPDF_Object::CloneRef(CPDF_IndirectObjects* pDoc) const
 {
-    if (this == NULL) {
-        return NULL;
-    }
     if (m_ObjNum) {
         return FX_NEW CPDF_Reference(pDoc, m_ObjNum);
     }
@@ -332,9 +310,6 @@ CPDF_Object* CPDF_Object::CloneRef(CPDF_IndirectObjects* pDoc) const
 }
 CFX_WideString CPDF_Object::GetUnicodeText(CFX_CharMap* pCharMap) const
 {
-    if (this == NULL) {
-        return CFX_WideString();
-    }
     if (m_Type == PDFOBJ_STRING) {
         return PDF_DecodeText(((CPDF_String*)this)->m_String, pCharMap);
     } else if (m_Type == PDFOBJ_STREAM) {
@@ -349,9 +324,6 @@ CFX_WideString CPDF_Object::GetUnicodeText(CFX_CharMap* pCharMap) const
 }
 void CPDF_Object::SetUnicodeText(FX_LPCWSTR pUnicodes, int len)
 {
-    if (this == NULL) {
-        return;
-    }
     if (m_Type == PDFOBJ_STRING) {
         ((CPDF_String*)this)->m_String = PDF_EncodeText(pUnicodes, len);
     } else if (m_Type == PDFOBJ_STREAM) {
@@ -411,13 +383,14 @@ CPDF_Array::~CPDF_Array()
     int size = m_Objects.GetSize();
     CPDF_Object** pList = (CPDF_Object**)m_Objects.GetData();
     for (int i = 0; i < size; i ++) {
-        pList[i]->Release();
+        if (pList[i])
+            pList[i]->Release();
     }
 }
 CFX_FloatRect CPDF_Array::GetRect()
 {
     CFX_FloatRect rect;
-    if (this == NULL || m_Type != PDFOBJ_ARRAY || m_Objects.GetSize() != 4) {
+    if (m_Type != PDFOBJ_ARRAY || m_Objects.GetSize() != 4) {
         return rect;
     }
     rect.left = GetNumber(0);
@@ -429,7 +402,7 @@ CFX_FloatRect CPDF_Array::GetRect()
 CFX_AffineMatrix CPDF_Array::GetMatrix()
 {
     CFX_AffineMatrix matrix;
-    if (this == NULL || m_Type != PDFOBJ_ARRAY || m_Objects.GetSize() != 6) {
+    if (m_Type != PDFOBJ_ARRAY || m_Objects.GetSize() != 6) {
         return matrix;
     }
     matrix.Set(GetNumber(0), GetNumber(1), GetNumber(2), GetNumber(3), GetNumber(4), GetNumber(5));
@@ -437,9 +410,6 @@ CFX_AffineMatrix CPDF_Array::GetMatrix()
 }
 CPDF_Object* CPDF_Array::GetElement(FX_DWORD i) const
 {
-    if (this == NULL) {
-        return NULL;
-    }
     if (i >= (FX_DWORD)m_Objects.GetSize()) {
         return NULL;
     }
@@ -447,9 +417,6 @@ CPDF_Object* CPDF_Array::GetElement(FX_DWORD i) const
 }
 CPDF_Object* CPDF_Array::GetElementValue(FX_DWORD i) const
 {
-    if (this == NULL) {
-        return NULL;
-    }
     if (i >= (FX_DWORD)m_Objects.GetSize()) {
         return NULL;
     }
@@ -457,23 +424,25 @@ CPDF_Object* CPDF_Array::GetElementValue(FX_DWORD i) const
 }
 CFX_ByteString CPDF_Array::GetString(FX_DWORD i) const
 {
-    if (this && i < (FX_DWORD)m_Objects.GetSize()) {
+    if (i < (FX_DWORD)m_Objects.GetSize()) {
         CPDF_Object* p = (CPDF_Object*)m_Objects.GetAt(i);
         return p->GetString();
     }
-    return CFX_ByteString();
+    else
+        return CFX_ByteString();
 }
 CFX_ByteStringC CPDF_Array::GetConstString(FX_DWORD i) const
 {
-    if (this && i < (FX_DWORD)m_Objects.GetSize()) {
+    if (i < (FX_DWORD)m_Objects.GetSize()) {
         CPDF_Object* p = (CPDF_Object*)m_Objects.GetAt(i);
         return p->GetConstString();
     }
-    return CFX_ByteStringC();
+    else
+        return CFX_ByteStringC();
 }
 int CPDF_Array::GetInteger(FX_DWORD i) const
 {
-    if (this == NULL || i >= (FX_DWORD)m_Objects.GetSize()) {
+    if (i >= (FX_DWORD)m_Objects.GetSize()) {
         return 0;
     }
     CPDF_Object* p = (CPDF_Object*)m_Objects.GetAt(i);
@@ -481,7 +450,7 @@ int CPDF_Array::GetInteger(FX_DWORD i) const
 }
 FX_FLOAT CPDF_Array::GetNumber(FX_DWORD i) const
 {
-    if (this == NULL || i >= (FX_DWORD)m_Objects.GetSize()) {
+    if (i >= (FX_DWORD)m_Objects.GetSize()) {
         return 0;
     }
     CPDF_Object* p = (CPDF_Object*)m_Objects.GetAt(i);
@@ -517,23 +486,25 @@ CPDF_Array* CPDF_Array::GetArray(FX_DWORD i) const
 }
 void CPDF_Array::RemoveAt(FX_DWORD i)
 {
-    ASSERT(this != NULL && m_Type == PDFOBJ_ARRAY);
+    ASSERT(m_Type == PDFOBJ_ARRAY);
     if (i >= (FX_DWORD)m_Objects.GetSize()) {
         return;
     }
     CPDF_Object* p = (CPDF_Object*)m_Objects.GetAt(i);
-    p->Release();
+    if (p)
+        p->Release();
     m_Objects.RemoveAt(i);
 }
 void CPDF_Array::SetAt(FX_DWORD i, CPDF_Object* pObj, CPDF_IndirectObjects* pObjs)
 {
-    ASSERT(this != NULL && m_Type == PDFOBJ_ARRAY);
+    ASSERT(m_Type == PDFOBJ_ARRAY);
     ASSERT(i < (FX_DWORD)m_Objects.GetSize());
     if (i >= (FX_DWORD)m_Objects.GetSize()) {
         return;
     }
     CPDF_Object* pOld = (CPDF_Object*)m_Objects.GetAt(i);
-    pOld->Release();
+    if (pOld)
+        pOld->Release();
     if (pObj->GetObjNum()) {
         ASSERT(pObjs != NULL);
         pObj = CPDF_Reference::Create(pObjs, pObj->GetObjNum());
@@ -560,29 +531,29 @@ void CPDF_Array::Add(CPDF_Object* pObj, CPDF_IndirectObjects* pObjs)
 }
 void CPDF_Array::AddName(const CFX_ByteString& str)
 {
-    ASSERT(this != NULL && m_Type == PDFOBJ_ARRAY);
+    ASSERT(m_Type == PDFOBJ_ARRAY);
     Add(FX_NEW CPDF_Name(str));
 }
 void CPDF_Array::AddString(const CFX_ByteString& str)
 {
-    ASSERT(this != NULL && m_Type == PDFOBJ_ARRAY);
+    ASSERT(m_Type == PDFOBJ_ARRAY);
     Add(FX_NEW CPDF_String(str));
 }
 void CPDF_Array::AddInteger(int i)
 {
-    ASSERT(this != NULL && m_Type == PDFOBJ_ARRAY);
+    ASSERT(m_Type == PDFOBJ_ARRAY);
     Add(FX_NEW CPDF_Number(i));
 }
 void CPDF_Array::AddNumber(FX_FLOAT f)
 {
-    ASSERT(this != NULL && m_Type == PDFOBJ_ARRAY);
+    ASSERT(m_Type == PDFOBJ_ARRAY);
     CPDF_Number* pNumber = FX_NEW CPDF_Number;
     pNumber->SetNumber(f);
     Add(pNumber);
 }
 void CPDF_Array::AddReference(CPDF_IndirectObjects* pDoc, FX_DWORD objnum)
 {
-    ASSERT(this != NULL && m_Type == PDFOBJ_ARRAY);
+    ASSERT(m_Type == PDFOBJ_ARRAY);
     Add(FX_NEW CPDF_Reference(pDoc, objnum));
 }
 FX_BOOL CPDF_Array::Identical(CPDF_Array* pOther) const
@@ -601,7 +572,8 @@ CPDF_Dictionary::~CPDF_Dictionary()
     FX_POSITION pos = m_Map.GetStartPosition();
     while (pos) {
         FX_LPVOID value = m_Map.GetNextValue(pos);
-        ((CPDF_Object*)value)->Release();
+        if (value)
+            ((CPDF_Object*)value)->Release();
     }
 }
 FX_POSITION CPDF_Dictionary::GetStartPos() const
@@ -619,123 +591,99 @@ CPDF_Object* CPDF_Dictionary::GetNextElement(FX_POSITION& pos, CFX_ByteString& k
 }
 CPDF_Object* CPDF_Dictionary::GetElement(FX_BSTR key) const
 {
-    if (this == NULL) {
-        return NULL;
-    }
     CPDF_Object* p = NULL;
     m_Map.Lookup(key, (void*&)p);
     return p;
 }
 CPDF_Object* CPDF_Dictionary::GetElementValue(FX_BSTR key) const
 {
-    if (this == NULL) {
-        return NULL;
-    }
     CPDF_Object* p = NULL;
     m_Map.Lookup(key, (void*&)p);
-    return p->GetDirect();
+    return p ? p->GetDirect() : NULL;
 }
 CFX_ByteString CPDF_Dictionary::GetString(FX_BSTR key) const
 {
-    if (this) {
-        CPDF_Object* p = NULL;
-        m_Map.Lookup(key, (void*&)p);
-        if (p) {
-            return p->GetString();
-        }
-    }
-    return CFX_ByteString();
+    CPDF_Object* p = NULL;
+    m_Map.Lookup(key, (void*&)p);
+    if (p)
+        return p->GetString();
+    else
+        return CFX_ByteString();
 }
 CFX_ByteStringC CPDF_Dictionary::GetConstString(FX_BSTR key) const
 {
-    if (this) {
-        CPDF_Object* p = NULL;
-        m_Map.Lookup(key, (void*&)p);
-        if (p) {
-            return p->GetConstString();
-        }
-    }
-    return CFX_ByteStringC();
+    CPDF_Object* p = NULL;
+    m_Map.Lookup(key, (void*&)p);
+    if (p)
+        return p->GetConstString();
+    else
+        return CFX_ByteStringC();
 }
 CFX_WideString CPDF_Dictionary::GetUnicodeText(FX_BSTR key, CFX_CharMap* pCharMap) const
 {
-    if (this) {
-        CPDF_Object* p = NULL;
-        m_Map.Lookup(key, (void*&)p);
-        if (p) {
-            if(p->GetType() == PDFOBJ_REFERENCE) {
-                p = ((CPDF_Reference*)p)->GetDirect();
-                return p->GetUnicodeText(pCharMap);
-            } else {
-                return p->GetUnicodeText(pCharMap);
-            }
+    CPDF_Object* p = NULL;
+    m_Map.Lookup(key, (void*&)p);
+    if (p) {
+        if(p->GetType() == PDFOBJ_REFERENCE) {
+            p = ((CPDF_Reference*)p)->GetDirect();
+            return p->GetUnicodeText(pCharMap);
+        } else {
+            return p->GetUnicodeText(pCharMap);
         }
     }
     return CFX_WideString();
 }
 CFX_ByteString CPDF_Dictionary::GetString(FX_BSTR key, FX_BSTR def) const
 {
-    if (this) {
-        CPDF_Object* p = NULL;
-        m_Map.Lookup(key, (void*&)p);
-        if (p) {
-            return p->GetString();
-        }
+    CPDF_Object* p = NULL;
+    m_Map.Lookup(key, (void*&)p);
+    if (p) {
+        return p->GetString();
     }
     return CFX_ByteString(def);
 }
 CFX_ByteStringC CPDF_Dictionary::GetConstString(FX_BSTR key, FX_BSTR def) const
 {
-    if (this) {
-        CPDF_Object* p = NULL;
-        m_Map.Lookup(key, (void*&)p);
-        if (p) {
-            return p->GetConstString();
-        }
-    }
-    return CFX_ByteStringC(def);
+    CPDF_Object* p = NULL;
+    m_Map.Lookup(key, (void*&)p);
+    if (p)
+        return p->GetConstString();
+    else
+        return CFX_ByteStringC(def);
 }
 int CPDF_Dictionary::GetInteger(FX_BSTR key) const
 {
-    if (this) {
-        CPDF_Object* p = NULL;
-        m_Map.Lookup(key, (void*&)p);
-        if (p) {
-            return p->GetInteger();
-        }
+    CPDF_Object* p = NULL;
+    m_Map.Lookup(key, (void*&)p);
+    if (p) {
+        return p->GetInteger();
     }
     return 0;
 }
 int CPDF_Dictionary::GetInteger(FX_BSTR key, int def) const
 {
-    if (this) {
-        CPDF_Object* p = NULL;
-        m_Map.Lookup(key, (void*&)p);
-        if (p) {
-            return p->GetInteger();
-        }
+    CPDF_Object* p = NULL;
+    m_Map.Lookup(key, (void*&)p);
+    if (p) {
+        return p->GetInteger();
     }
     return def;
 }
 FX_FLOAT CPDF_Dictionary::GetNumber(FX_BSTR key) const
 {
-    if (this) {
-        CPDF_Object* p = NULL;
-        m_Map.Lookup(key, (void*&)p);
-        if (p) {
-            return p->GetNumber();
-        }
+    CPDF_Object* p = NULL;
+    m_Map.Lookup(key, (void*&)p);
+    if (p) {
+        return p->GetNumber();
     }
     return 0;
 }
 FX_BOOL CPDF_Dictionary::GetBoolean(FX_BSTR key, FX_BOOL bDefault) const
 {
-    if (this) {
-        CPDF_Object* p = NULL;
-        m_Map.Lookup(key, (void*&)p);
-        if (p && p->GetType() == PDFOBJ_BOOLEAN) {
-            return p->GetInteger();
-        }
+    CPDF_Object* p = NULL;
+    m_Map.Lookup(key, (void*&)p);
+    if (p && p->GetType() == PDFOBJ_BOOLEAN) {
+        return p->GetInteger();
     }
     return bDefault;
 }
@@ -787,23 +735,19 @@ CFX_AffineMatrix CPDF_Dictionary::GetMatrix(FX_BSTR key) const
 }
 FX_BOOL CPDF_Dictionary::KeyExist(FX_BSTR key) const
 {
-    if (this == NULL) {
-        return FALSE;
-    }
     FX_LPVOID value;
     return m_Map.Lookup(key, value);
 }
 void CPDF_Dictionary::SetAt(FX_BSTR key, CPDF_Object* pObj, CPDF_IndirectObjects* pObjs)
 {
-    ASSERT(this != NULL && m_Type == PDFOBJ_DICTIONARY);
+    ASSERT(m_Type == PDFOBJ_DICTIONARY);
     CPDF_Object* p = NULL;
     m_Map.Lookup(key, (void*&)p);
     if (p == pObj) {
         return;
     }
-    if (p) {
+    if (p)
         p->Release();
-    }
     if (pObj) {
         if (pObj->GetObjNum()) {
             ASSERT(pObjs != NULL);
@@ -816,12 +760,12 @@ void CPDF_Dictionary::SetAt(FX_BSTR key, CPDF_Object* pObj, CPDF_IndirectObjects
 }
 void CPDF_Dictionary::AddValue(FX_BSTR key, CPDF_Object* pObj)
 {
-    ASSERT(this != NULL && m_Type == PDFOBJ_DICTIONARY);
+    ASSERT(m_Type == PDFOBJ_DICTIONARY);
     m_Map.AddValue(key, pObj);
 }
 void CPDF_Dictionary::RemoveAt(FX_BSTR key)
 {
-    ASSERT(this != NULL && m_Type == PDFOBJ_DICTIONARY);
+    ASSERT(m_Type == PDFOBJ_DICTIONARY);
     CPDF_Object* p = NULL;
     m_Map.Lookup(key, (void*&)p);
     if (p == NULL) {
@@ -832,7 +776,7 @@ void CPDF_Dictionary::RemoveAt(FX_BSTR key)
 }
 void CPDF_Dictionary::ReplaceKey(FX_BSTR oldkey, FX_BSTR newkey)
 {
-    ASSERT(this != NULL && m_Type == PDFOBJ_DICTIONARY);
+    ASSERT(m_Type == PDFOBJ_DICTIONARY);
     CPDF_Object* p = NULL;
     m_Map.Lookup(oldkey, (void*&)p);
     if (p == NULL) {
@@ -843,12 +787,6 @@ void CPDF_Dictionary::ReplaceKey(FX_BSTR oldkey, FX_BSTR newkey)
 }
 FX_BOOL CPDF_Dictionary::Identical(CPDF_Dictionary* pOther) const
 {
-    if (this == NULL) {
-        if (pOther == NULL) {
-            return TRUE;
-        }
-        return FALSE;
-    }
     if (pOther == NULL) {
         return FALSE;
     }
@@ -860,6 +798,8 @@ FX_BOOL CPDF_Dictionary::Identical(CPDF_Dictionary* pOther) const
         CFX_ByteString key;
         FX_LPVOID value;
         m_Map.GetNextAssoc(pos, key, value);
+        if (!value)
+            return FALSE;
         if (!((CPDF_Object*)value)->IsIdentical(pOther->GetElement(key))) {
             return FALSE;
         }
@@ -1014,6 +954,9 @@ void CPDF_Stream::InitStream(IFX_FileRead *pFile, CPDF_Dictionary* pDict)
 }
 FX_BOOL CPDF_Stream::Identical(CPDF_Stream* pOther) const
 {
+    if (!m_pDict)
+        return pOther->m_pDict ? FALSE : TRUE;
+
     if (!m_pDict->Identical(pOther->m_pDict)) {
         return FALSE;
     }
diff --git a/core/src/fpdfapi/fpdf_parser/fpdf_parser_parser.cpp b/core/src/fpdfapi/fpdf_parser/fpdf_parser_parser.cpp
index c705ea7357..5e926c31b9 100644
--- a/core/src/fpdfapi/fpdf_parser/fpdf_parser_parser.cpp
+++ b/core/src/fpdfapi/fpdf_parser/fpdf_parser_parser.cpp
@@ -78,7 +78,7 @@ void CPDF_Parser::CloseParser(FX_BOOL bReParse)
     }
     ReleaseEncryptHandler();
     SetEncryptDictionary(NULL);
-    if (m_bOwnFileRead && m_Syntax.m_pFileAccess != NULL) {
+    if (m_bOwnFileRead && m_Syntax.m_pFileAccess) {
         m_Syntax.m_pFileAccess->Release();
         m_Syntax.m_pFileAccess = NULL;
     }
@@ -96,7 +96,8 @@ void CPDF_Parser::CloseParser(FX_BOOL bReParse)
     m_ObjVersion.RemoveAll();
     FX_INT32 iLen = m_Trailers.GetSize();
     for (FX_INT32 i = 0; i < iLen; ++i) {
-        m_Trailers.GetAt(i)->Release();
+        if (CPDF_Dictionary* trailer = m_Trailers.GetAt(i))
+            trailer->Release();
     }
     m_Trailers.RemoveAll();
     if (m_pLinearized) {
@@ -1110,7 +1111,7 @@ FX_BOOL CPDF_Parser::LoadCrossRefV5(FX_FILESIZE pos, FX_FILESIZE& prev, FX_BOOL
 }
 CPDF_Array* CPDF_Parser::GetIDArray()
 {
-    CPDF_Object* pID = m_pTrailer->GetElement(FX_BSTRC("ID"));
+    CPDF_Object* pID = m_pTrailer ? m_pTrailer->GetElement(FX_BSTRC("ID")) : NULL;
     if (pID == NULL) {
         return NULL;
     }
@@ -1125,7 +1126,7 @@ CPDF_Array* CPDF_Parser::GetIDArray()
 }
 FX_DWORD CPDF_Parser::GetRootObjNum()
 {
-    CPDF_Reference* pRef = (CPDF_Reference*)m_pTrailer->GetElement(FX_BSTRC("Root"));
+    CPDF_Reference* pRef = m_pTrailer ? (CPDF_Reference*)m_pTrailer->GetElement(FX_BSTRC("Root")) : NULL;
     if (pRef == NULL || pRef->GetType() != PDFOBJ_REFERENCE) {
         return 0;
     }
@@ -1133,7 +1134,7 @@ FX_DWORD CPDF_Parser::GetRootObjNum()
 }
 FX_DWORD CPDF_Parser::GetInfoObjNum()
 {
-    CPDF_Reference* pRef = (CPDF_Reference*)m_pTrailer->GetElement(FX_BSTRC("Info"));
+    CPDF_Reference* pRef = m_pTrailer ? (CPDF_Reference*)m_pTrailer->GetElement(FX_BSTRC("Info")) : NULL;
     if (pRef == NULL || pRef->GetType() != PDFOBJ_REFERENCE) {
         return 0;
     }
@@ -1491,7 +1492,7 @@ FX_BOOL CPDF_Parser::IsLinearizedFile(IFX_FileRead* pFileAccess, FX_DWORD offset
     if (!m_pLinearized) {
         return FALSE;
     }
-    if (m_pLinearized->GetDict()->GetElement(FX_BSTRC("Linearized"))) {
+    if (m_pLinearized->GetDict() && m_pLinearized->GetDict()->GetElement(FX_BSTRC("Linearized"))) {
         m_Syntax.GetNextWord(bIsNumber);
         CPDF_Object *pLen = m_pLinearized->GetDict()->GetElement(FX_BSTRC("L"));
         if (!pLen) {
@@ -2150,7 +2151,8 @@ CPDF_Object* CPDF_SyntaxParser::GetObject(CPDF_IndirectObjects* pObjList, FX_DWO
             FX_BOOL bIsNumber;
             CFX_ByteString key = GetNextWord(bIsNumber);
             if (key.IsEmpty()) {
-                pDict->Release();
+                if (pDict)
+                    pDict->Release();
                 return NULL;
             }
             FX_FILESIZE SavedPos = m_Pos - key.GetLength();
@@ -2206,7 +2208,8 @@ CPDF_Object* CPDF_SyntaxParser::GetObject(CPDF_IndirectObjects* pObjList, FX_DWO
             if (pStream) {
                 return pStream;
             }
-            pDict->Release();
+            if (pDict)
+                pDict->Release();
             return NULL;
         } else {
             m_Pos = SavedPos;
@@ -2307,7 +2310,8 @@ CPDF_Object* CPDF_SyntaxParser::GetObjectByStrict(CPDF_IndirectObjects* pObjList
                 if (m_WordBuffer[0] == ']') {
                     return pArray;
                 }
-                pArray->Release();
+                if (pArray)
+                    pArray->Release();
                 return NULL;
             }
             pArray->Add(pObj);
@@ -2332,7 +2336,8 @@ CPDF_Object* CPDF_SyntaxParser::GetObjectByStrict(CPDF_IndirectObjects* pObjList
             FX_FILESIZE SavedPos = m_Pos;
             CFX_ByteString key = GetNextWord(bIsNumber);
             if (key.IsEmpty()) {
-                pDict->Release();
+                if (pDict)
+                    pDict->Release();
                 return NULL;
             }
             if (key == FX_BSTRC(">>")) {
@@ -2348,7 +2353,8 @@ CPDF_Object* CPDF_SyntaxParser::GetObjectByStrict(CPDF_IndirectObjects* pObjList
             key = PDF_NameDecode(key);
             CPDF_Object* pObj = GetObject(pObjList, objnum, gennum, level + 1);
             if (pObj == NULL) {
-                pDict->Release();
+                if (pDict)
+                    pDict->Release();
                 FX_BYTE ch;
                 while (1) {
                     if (!GetNextChar(ch)) {
@@ -2380,7 +2386,8 @@ CPDF_Object* CPDF_SyntaxParser::GetObjectByStrict(CPDF_IndirectObjects* pObjList
             if (pStream) {
                 return pStream;
             }
-            pDict->Release();
+            if (pDict)
+                pDict->Release();
             return NULL;
         } else {
             m_Pos = SavedPos;
@@ -2835,7 +2842,7 @@ FX_BOOL CPDF_DataAvail::IsObjectsAvail(CFX_PtrArray& obj_array, FX_BOOL bParsePa
                 pObj = pObj->GetDict();
             case PDFOBJ_DICTIONARY: {
                     CPDF_Dictionary *pDict = pObj->GetDict();
-                    if (pDict->GetString("Type") == "Page" && !bParsePage) {
+                    if (pDict && pDict->GetString("Type") == "Page" && !bParsePage) {
                         continue;
                     }
                     FX_POSITION pos = pDict->GetStartPos();
@@ -3157,7 +3164,7 @@ FX_BOOL CPDF_DataAvail::CheckRoot(IFX_DownloadHints* pHints)
 FX_BOOL CPDF_DataAvail::PreparePageItem()
 {
     CPDF_Dictionary *pRoot = m_pDocument->GetRoot();
-    CPDF_Reference* pRef = (CPDF_Reference*)pRoot->GetElement(FX_BSTRC("Pages"));
+    CPDF_Reference* pRef = pRoot ? (CPDF_Reference*)pRoot->GetElement(FX_BSTRC("Pages")) : NULL;
     if (pRef == NULL || pRef->GetType() != PDFOBJ_REFERENCE) {
         m_docStatus = PDF_DATAAVAIL_ERROR;
         return FALSE;
@@ -3270,7 +3277,8 @@ FX_BOOL CPDF_DataAvail::GetPageKids(CPDF_Parser *pParser, CPDF_Object *pPages)
         m_docStatus = PDF_DATAAVAIL_ERROR;
         return FALSE;
     }
-    CPDF_Object *pKids = pPages->GetDict()->GetElement(FX_BSTRC("Kids"));
+    CPDF_Dictionary* pDict = pPages->GetDict();
+    CPDF_Object *pKids = pDict ? pDict->GetElement(FX_BSTRC("Kids")) : NULL;
     if (!pKids) {
         return TRUE;
     }
@@ -3344,17 +3352,18 @@ FX_BOOL CPDF_DataAvail::CheckHeader(IFX_DownloadHints* pHints)
 FX_BOOL CPDF_DataAvail::CheckFirstPage(IFX_DownloadHints *pHints)
 {
     FX_DWORD dwFirstPageEndOffset = 0;
-    CPDF_Object *pEndOffSet = m_pLinearized->GetDict()->GetElement(FX_BSTRC("E"));
+    CPDF_Dictionary* pDict = m_pLinearized->GetDict();
+    CPDF_Object *pEndOffSet = pDict ? pDict->GetElement(FX_BSTRC("E")) : NULL;
     if (!pEndOffSet) {
         m_docStatus = PDF_DATAAVAIL_ERROR;
         return FALSE;
     }
-    CPDF_Object *pXRefOffset  = m_pLinearized->GetDict()->GetElement(FX_BSTRC("T"));
+    CPDF_Object *pXRefOffset = pDict ? pDict->GetElement(FX_BSTRC("T")) : NULL;
     if (!pXRefOffset) {
         m_docStatus = PDF_DATAAVAIL_ERROR;
         return FALSE;
     }
-    CPDF_Object *pFileLen = m_pLinearized->GetDict()->GetElement(FX_BSTRC("L"));
+    CPDF_Object *pFileLen = pDict ? pDict->GetElement(FX_BSTRC("L")) : NULL;
     if (!pFileLen) {
         m_docStatus = PDF_DATAAVAIL_ERROR;
         return FALSE;
@@ -3473,7 +3482,7 @@ FX_BOOL CPDF_DataAvail::IsLinearizedFile(FX_LPBYTE pData, FX_DWORD dwLen)
     if (!m_pLinearized) {
         return FALSE;
     }
-    if (m_pLinearized->GetDict()->GetElement(FX_BSTRC("Linearized"))) {
+    if (m_pLinearized->GetDict() && m_pLinearized->GetDict()->GetElement(FX_BSTRC("Linearized"))) {
         CPDF_Object *pLen = m_pLinearized->GetDict()->GetElement(FX_BSTRC("L"));
         if (!pLen) {
             return FALSE;
@@ -3548,7 +3557,8 @@ FX_DWORD CPDF_DataAvail::CheckCrossRefStream(IFX_DownloadHints* pHints, FX_FILES
             m_Pos += m_parser.m_Syntax.SavePos();
             return 0;
         }
-        CPDF_Object *pName = pObj->GetDict()->GetElement(FX_BSTRC("Type"));
+        CPDF_Dictionary* pDict = pObj->GetDict();
+        CPDF_Object *pName = pDict ? pDict->GetElement(FX_BSTRC("Type")) : NULL;
         if (pName && pName->GetType() == PDFOBJ_NAME) {
             if (pName->GetString() == FX_BSTRC("XRef")) {
                 m_Pos += m_parser.m_Syntax.SavePos();
@@ -3908,10 +3918,11 @@ FX_BOOL CPDF_DataAvail::CheckUnkownPageNode(FX_DWORD dwPageNo, CPDF_PageNode *pP
         return FALSE;
     }
     pPageNode->m_dwPageNo = dwPageNo;
-    CFX_ByteString type = pPage->GetDict()->GetString(FX_BSTRC("Type"));
+    CPDF_Dictionary* pDict = pPage->GetDict();
+    CFX_ByteString type = pDict ? pDict->GetString(FX_BSTRC("Type")) : CFX_ByteString();
     if (type == FX_BSTRC("Pages")) {
         pPageNode->m_type = PDF_PAGENODE_PAGES;
-        CPDF_Object *pKids = pPage->GetDict()->GetElement(FX_BSTRC("Kids"));
+        CPDF_Object *pKids = pDict->GetElement(FX_BSTRC("Kids"));
         if (!pKids) {
             m_docStatus = PDF_DATAAVAIL_PAGE;
             return TRUE;