Add proper const/non-const versions of CPDF_Dictionary::GetDictFor().

BUG=pdfium:234

Change-Id: I6fde00c976ad4bb9cab632f465cf292f5b1da3d2
Reviewed-on: https://pdfium-review.googlesource.com/32914
Commit-Queue: Lei Zhang <thestig@chromium.org>
Reviewed-by: dsinclair <dsinclair@chromium.org>

11 files changed, 74 insertions, 51 deletions

diff --git a/core/fpdfapi/font/cpdf_font.cpp b/core/fpdfapi/font/cpdf_font.cpp
index cc867d69d9..0bba1057e7 100644
--- a/core/fpdfapi/font/cpdf_font.cpp
+++ b/core/fpdfapi/font/cpdf_font.cpp
@@ -324,7 +324,8 @@ std::unique_ptr<CPDF_Font> CPDF_Font::Create(CPDF_Document* pDoc,
     ByteString tag = pFontDict->GetStringFor("BaseFont").Left(4);
     for (size_t i = 0; i < FX_ArraySize(kChineseFontNames); ++i) {
       if (tag == ByteString(kChineseFontNames[i], 4)) {
-        CPDF_Dictionary* pFontDesc = pFontDict->GetDictFor("FontDescriptor");
+        const CPDF_Dictionary* pFontDesc =
+            pFontDict->GetDictFor("FontDescriptor");
         if (!pFontDesc || !pFontDesc->KeyExist("FontFile2"))
           pFont = pdfium::MakeUnique<CPDF_CIDFont>();
         break;
diff --git a/core/fpdfapi/page/cpdf_docpagedata.cpp b/core/fpdfapi/page/cpdf_docpagedata.cpp
index 92dca138cf..37283b9d64 100644
--- a/core/fpdfapi/page/cpdf_docpagedata.cpp
+++ b/core/fpdfapi/page/cpdf_docpagedata.cpp
@@ -241,7 +241,7 @@ CPDF_ColorSpace* CPDF_DocPageData::GetColorSpaceInternal(
     ByteString name = pCSObj->GetString();
     CPDF_ColorSpace* pCS = CPDF_ColorSpace::ColorspaceFromName(name);
     if (!pCS && pResources) {
-      CPDF_Dictionary* pList = pResources->GetDictFor("ColorSpace");
+      const CPDF_Dictionary* pList = pResources->GetDictFor("ColorSpace");
       if (pList) {
         return GetColorSpaceInternal(pList->GetDirectObjectFor(name), nullptr,
                                      pVisited, pVisitedInternal);
@@ -250,7 +250,7 @@ CPDF_ColorSpace* CPDF_DocPageData::GetColorSpaceInternal(
     if (!pCS || !pResources)
       return pCS;
 
-    CPDF_Dictionary* pColorSpaces = pResources->GetDictFor("ColorSpace");
+    const CPDF_Dictionary* pColorSpaces = pResources->GetDictFor("ColorSpace");
     if (!pColorSpaces)
       return pCS;
 
diff --git a/core/fpdfapi/parser/cpdf_dictionary.cpp b/core/fpdfapi/parser/cpdf_dictionary.cpp
index 1ede5e707a..5257a20586 100644
--- a/core/fpdfapi/parser/cpdf_dictionary.cpp
+++ b/core/fpdfapi/parser/cpdf_dictionary.cpp
@@ -130,7 +130,19 @@ bool CPDF_Dictionary::GetBooleanFor(const ByteString& key,
   return ToBoolean(p) ? p->GetInteger() != 0 : bDefault;
 }
 
-CPDF_Dictionary* CPDF_Dictionary::GetDictFor(const ByteString& key) const {
+const CPDF_Dictionary* CPDF_Dictionary::GetDictFor(
+    const ByteString& key) const {
+  CPDF_Object* p = GetDirectObjectFor(key);
+  if (!p)
+    return nullptr;
+  if (CPDF_Dictionary* pDict = p->AsDictionary())
+    return pDict;
+  if (CPDF_Stream* pStream = p->AsStream())
+    return pStream->GetDict();
+  return nullptr;
+}
+
+CPDF_Dictionary* CPDF_Dictionary::GetDictFor(const ByteString& key) {
   CPDF_Object* p = GetDirectObjectFor(key);
   if (!p)
     return nullptr;
diff --git a/core/fpdfapi/parser/cpdf_dictionary.h b/core/fpdfapi/parser/cpdf_dictionary.h
index df789aa7b4..5240ab3b5c 100644
--- a/core/fpdfapi/parser/cpdf_dictionary.h
+++ b/core/fpdfapi/parser/cpdf_dictionary.h
@@ -51,7 +51,8 @@ class CPDF_Dictionary : public CPDF_Object {
   int GetIntegerFor(const ByteString& key, int default_int) const;
   bool GetBooleanFor(const ByteString& key, bool bDefault = false) const;
   float GetNumberFor(const ByteString& key) const;
-  CPDF_Dictionary* GetDictFor(const ByteString& key) const;
+  const CPDF_Dictionary* GetDictFor(const ByteString& key) const;
+  CPDF_Dictionary* GetDictFor(const ByteString& key);
   const CPDF_Stream* GetStreamFor(const ByteString& key) const;
   CPDF_Stream* GetStreamFor(const ByteString& key);
   const CPDF_Array* GetArrayFor(const ByteString& key) const;
diff --git a/core/fpdfapi/parser/cpdf_document.cpp b/core/fpdfapi/parser/cpdf_document.cpp
index 5264d4e795..5479a06174 100644
--- a/core/fpdfapi/parser/cpdf_document.cpp
+++ b/core/fpdfapi/parser/cpdf_document.cpp
@@ -322,11 +322,16 @@ void CPDF_Document::ResetTraversal() {
   m_pTreeTraversal.clear();
 }
 
-CPDF_Dictionary* CPDF_Document::GetPagesDict() const {
+const CPDF_Dictionary* CPDF_Document::GetPagesDict() const {
   const CPDF_Dictionary* pRoot = GetRoot();
   return pRoot ? pRoot->GetDictFor("Pages") : nullptr;
 }
 
+CPDF_Dictionary* CPDF_Document::GetPagesDict() {
+  CPDF_Dictionary* pRoot = GetRoot();
+  return pRoot ? pRoot->GetDictFor("Pages") : nullptr;
+}
+
 bool CPDF_Document::IsPageLoaded(int iPage) const {
   return !!m_PageList[iPage];
 }
@@ -363,7 +368,7 @@ void CPDF_Document::SetPageObjNum(int iPage, uint32_t objNum) {
   m_PageList[iPage] = objNum;
 }
 
-int CPDF_Document::FindPageIndex(CPDF_Dictionary* pNode,
+int CPDF_Document::FindPageIndex(const CPDF_Dictionary* pNode,
                                  uint32_t* skip_count,
                                  uint32_t objnum,
                                  int* index,
@@ -379,7 +384,7 @@ int CPDF_Document::FindPageIndex(CPDF_Dictionary* pNode,
     return -1;
   }
 
-  CPDF_Array* pKidList = pNode->GetArrayFor("Kids");
+  const CPDF_Array* pKidList = pNode->GetArrayFor("Kids");
   if (!pKidList)
     return -1;
 
@@ -395,14 +400,14 @@ int CPDF_Document::FindPageIndex(CPDF_Dictionary* pNode,
 
   if (count && count == pKidList->GetCount()) {
     for (size_t i = 0; i < count; i++) {
-      CPDF_Reference* pKid = ToReference(pKidList->GetObjectAt(i));
+      const CPDF_Reference* pKid = ToReference(pKidList->GetObjectAt(i));
       if (pKid && pKid->GetRefObjNum() == objnum)
         return static_cast<int>(*index + i);
     }
   }
 
   for (size_t i = 0; i < pKidList->GetCount(); i++) {
-    CPDF_Dictionary* pKid = pKidList->GetDictAt(i);
+    const CPDF_Dictionary* pKid = pKidList->GetDictAt(i);
     if (!pKid || pKid == pNode)
       continue;
 
@@ -426,7 +431,7 @@ int CPDF_Document::GetPageIndex(uint32_t objnum) {
       bSkipped = true;
     }
   }
-  CPDF_Dictionary* pPages = GetPagesDict();
+  const CPDF_Dictionary* pPages = GetPagesDict();
   if (!pPages)
     return -1;
 
@@ -445,7 +450,7 @@ int CPDF_Document::GetPageCount() const {
   return pdfium::CollectionSize<int>(m_PageList);
 }
 
-int CPDF_Document::RetrievePageCount() const {
+int CPDF_Document::RetrievePageCount() {
   CPDF_Dictionary* pPages = GetPagesDict();
   if (!pPages)
     return 0;
@@ -576,7 +581,7 @@ bool CPDF_Document::InsertDeletePDFPage(CPDF_Dictionary* pPages,
 }
 
 bool CPDF_Document::InsertNewPage(int iPage, CPDF_Dictionary* pPageDict) {
-  const CPDF_Dictionary* pRoot = GetRoot();
+  CPDF_Dictionary* pRoot = GetRoot();
   CPDF_Dictionary* pPages = pRoot ? pRoot->GetDictFor("Pages") : nullptr;
   if (!pPages)
     return false;
diff --git a/core/fpdfapi/parser/cpdf_document.h b/core/fpdfapi/parser/cpdf_document.h
index b169175668..356d341302 100644
--- a/core/fpdfapi/parser/cpdf_document.h
+++ b/core/fpdfapi/parser/cpdf_document.h
@@ -115,10 +115,10 @@ class CPDF_Document : public CPDF_IndirectObjectHolder {
 
  protected:
   // Retrieve page count information by getting count value from the tree nodes
-  int RetrievePageCount() const;
+  int RetrievePageCount();
   // When this method is called, m_pTreeTraversal[level] exists.
   CPDF_Dictionary* TraversePDFPages(int iPage, int* nPagesToGo, size_t level);
-  int FindPageIndex(CPDF_Dictionary* pNode,
+  int FindPageIndex(const CPDF_Dictionary* pNode,
                     uint32_t* skip_count,
                     uint32_t objnum,
                     int* index,
@@ -126,7 +126,8 @@ class CPDF_Document : public CPDF_IndirectObjectHolder {
   std::unique_ptr<CPDF_Object> ParseIndirectObject(uint32_t objnum) override;
   void LoadDocInternal();
   size_t CalculateEncodingDict(int charset, CPDF_Dictionary* pBaseDict);
-  CPDF_Dictionary* GetPagesDict() const;
+  const CPDF_Dictionary* GetPagesDict() const;
+  CPDF_Dictionary* GetPagesDict();
   CPDF_Dictionary* ProcessbCJK(
       CPDF_Dictionary* pBaseDict,
       int charset,
diff --git a/core/fpdfapi/parser/cpdf_security_handler.cpp b/core/fpdfapi/parser/cpdf_security_handler.cpp
index 7eb5c42f72..eeba53ef34 100644
--- a/core/fpdfapi/parser/cpdf_security_handler.cpp
+++ b/core/fpdfapi/parser/cpdf_security_handler.cpp
@@ -130,17 +130,17 @@ static bool LoadCryptInfo(const CPDF_Dictionary* pEncryptDict,
   cipher = FXCIPHER_RC4;
   keylen = 0;
   if (Version >= 4) {
-    CPDF_Dictionary* pCryptFilters = pEncryptDict->GetDictFor("CF");
-    if (!pCryptFilters) {
+    const CPDF_Dictionary* pCryptFilters = pEncryptDict->GetDictFor("CF");
+    if (!pCryptFilters)
       return false;
-    }
+
     if (name == "Identity") {
       cipher = FXCIPHER_NONE;
     } else {
-      CPDF_Dictionary* pDefFilter = pCryptFilters->GetDictFor(name);
-      if (!pDefFilter) {
+      const CPDF_Dictionary* pDefFilter = pCryptFilters->GetDictFor(name);
+      if (!pDefFilter)
         return false;
-      }
+
       int nKeyBits = 0;
       if (Version == 4) {
         nKeyBits = pDefFilter->GetIntegerFor("Length", 0);
diff --git a/fpdfsdk/formfiller/cba_fontmap.cpp b/fpdfsdk/formfiller/cba_fontmap.cpp
index 6b31de7b37..d219ca40b7 100644
--- a/fpdfsdk/formfiller/cba_fontmap.cpp
+++ b/fpdfsdk/formfiller/cba_fontmap.cpp
@@ -93,11 +93,11 @@ CPDF_Font* CBA_FontMap::FindFontSameCharset(ByteString* sFontAlias,
   if (!pRootDict)
     return nullptr;
 
-  CPDF_Dictionary* pAcroFormDict = pRootDict->GetDictFor("AcroForm");
+  const CPDF_Dictionary* pAcroFormDict = pRootDict->GetDictFor("AcroForm");
   if (!pAcroFormDict)
     return nullptr;
 
-  CPDF_Dictionary* pDRDict = pAcroFormDict->GetDictFor("DR");
+  const CPDF_Dictionary* pDRDict = pAcroFormDict->GetDictFor("DR");
   if (!pDRDict)
     return nullptr;
 
@@ -108,13 +108,13 @@ CPDF_Document* CBA_FontMap::GetDocument() {
   return m_pDocument.Get();
 }
 
-CPDF_Font* CBA_FontMap::FindResFontSameCharset(CPDF_Dictionary* pResDict,
+CPDF_Font* CBA_FontMap::FindResFontSameCharset(const CPDF_Dictionary* pResDict,
                                                ByteString* sFontAlias,
                                                int32_t nCharset) {
   if (!pResDict)
     return nullptr;
 
-  CPDF_Dictionary* pFonts = pResDict->GetDictFor("Font");
+  const CPDF_Dictionary* pFonts = pResDict->GetDictFor("Font");
   if (!pFonts)
     return nullptr;
 
@@ -197,7 +197,7 @@ CPDF_Font* CBA_FontMap::GetAnnotDefaultFont(ByteString* sAlias) {
   CPDF_Dictionary* pAcroFormDict = nullptr;
   const bool bWidget = (m_pAnnotDict->GetStringFor("Subtype") == "Widget");
   if (bWidget) {
-    const CPDF_Dictionary* pRootDict = m_pDocument->GetRoot();
+    CPDF_Dictionary* pRootDict = m_pDocument->GetRoot();
     if (pRootDict)
       pAcroFormDict = pRootDict->GetDictFor("AcroForm");
   }
diff --git a/fpdfsdk/formfiller/cba_fontmap.h b/fpdfsdk/formfiller/cba_fontmap.h
index 45df8c82ad..9d9f2e002a 100644
--- a/fpdfsdk/formfiller/cba_fontmap.h
+++ b/fpdfsdk/formfiller/cba_fontmap.h
@@ -30,7 +30,7 @@ class CBA_FontMap : public CPWL_FontMap {
                                  int32_t nCharset) override;
   void AddedFont(CPDF_Font* pFont, const ByteString& sFontAlias) override;
 
-  CPDF_Font* FindResFontSameCharset(CPDF_Dictionary* pResDict,
+  CPDF_Font* FindResFontSameCharset(const CPDF_Dictionary* pResDict,
                                     ByteString* sFontAlias,
                                     int32_t nCharset);
   CPDF_Font* GetAnnotDefaultFont(ByteString* csNameTag);
diff --git a/fpdfsdk/fpdf_edit_embeddertest.cpp b/fpdfsdk/fpdf_edit_embeddertest.cpp
index ebf356af45..458ae0022a 100644
--- a/fpdfsdk/fpdf_edit_embeddertest.cpp
+++ b/fpdfsdk/fpdf_edit_embeddertest.cpp
@@ -38,7 +38,7 @@ class FPDFEditEmbeddertest : public EmbedderTest {
                            bool italic,
                            uint32_t size,
                            const uint8_t* data) {
-    CPDF_Dictionary* font_desc = font_dict->GetDictFor("FontDescriptor");
+    const CPDF_Dictionary* font_desc = font_dict->GetDictFor("FontDescriptor");
     ASSERT_TRUE(font_desc);
     EXPECT_EQ("FontDescriptor", font_desc->GetStringFor("Type"));
     EXPECT_EQ(font_dict->GetStringFor("BaseFont"),
@@ -54,7 +54,7 @@ class FPDFEditEmbeddertest : public EmbedderTest {
     EXPECT_TRUE(FontStyleIsNonSymbolic(font_flags));
     ASSERT_TRUE(font_desc->KeyExist("FontBBox"));
 
-    CPDF_Array* fontBBox = font_desc->GetArrayFor("FontBBox");
+    const CPDF_Array* fontBBox = font_desc->GetArrayFor("FontBBox");
     ASSERT_TRUE(fontBBox);
     EXPECT_EQ(4U, fontBBox->GetCount());
     // Check that the coordinates are in the preferred order according to spec
@@ -75,7 +75,7 @@ class FPDFEditEmbeddertest : public EmbedderTest {
     EXPECT_FALSE(font_desc->KeyExist(absent));
 
     // Check that the font stream is the one that was provided
-    CPDF_Stream* font_stream = font_desc->GetStreamFor(present);
+    const CPDF_Stream* font_stream = font_desc->GetStreamFor(present);
     ASSERT_EQ(size, font_stream->GetRawSize());
     if (font_type == FPDF_FONT_TRUETYPE) {
       ASSERT_EQ(static_cast<int>(size),
@@ -1078,7 +1078,8 @@ TEST_F(FPDFEditEmbeddertest, LoadCIDType0Font) {
   EXPECT_EQ("Font", cidfont_dict->GetStringFor("Type"));
   EXPECT_EQ("CIDFontType0", cidfont_dict->GetStringFor("Subtype"));
   EXPECT_EQ("Times New Roman", cidfont_dict->GetStringFor("BaseFont"));
-  CPDF_Dictionary* cidinfo_dict = cidfont_dict->GetDictFor("CIDSystemInfo");
+  const CPDF_Dictionary* cidinfo_dict =
+      cidfont_dict->GetDictFor("CIDSystemInfo");
   ASSERT_TRUE(cidinfo_dict);
   EXPECT_EQ("Adobe", cidinfo_dict->GetStringFor("Registry"));
   EXPECT_EQ("Identity", cidinfo_dict->GetStringFor("Ordering"));
@@ -1121,7 +1122,8 @@ TEST_F(FPDFEditEmbeddertest, LoadCIDType2Font) {
   EXPECT_EQ("Font", cidfont_dict->GetStringFor("Type"));
   EXPECT_EQ("CIDFontType2", cidfont_dict->GetStringFor("Subtype"));
   EXPECT_EQ("Arial Italic", cidfont_dict->GetStringFor("BaseFont"));
-  CPDF_Dictionary* cidinfo_dict = cidfont_dict->GetDictFor("CIDSystemInfo");
+  const CPDF_Dictionary* cidinfo_dict =
+      cidfont_dict->GetDictFor("CIDSystemInfo");
   ASSERT_TRUE(cidinfo_dict);
   EXPECT_EQ("Adobe", cidinfo_dict->GetStringFor("Registry"));
   EXPECT_EQ("Identity", cidinfo_dict->GetStringFor("Ordering"));
diff --git a/fpdfsdk/fpdfxfa/cpdfxfa_docenvironment.cpp b/fpdfsdk/fpdfxfa/cpdfxfa_docenvironment.cpp
index cc7a8898e8..f9f5981efb 100644
--- a/fpdfsdk/fpdfxfa/cpdfxfa_docenvironment.cpp
+++ b/fpdfsdk/fpdfxfa/cpdfxfa_docenvironment.cpp
@@ -462,24 +462,24 @@ void CPDFXFA_DocEnvironment::ExportData(CXFA_FFDoc* hDoc,
     if (!pRoot)
       return;
 
-    CPDF_Dictionary* pAcroForm = pRoot->GetDictFor("AcroForm");
+    const CPDF_Dictionary* pAcroForm = pRoot->GetDictFor("AcroForm");
     if (!pAcroForm)
       return;
 
-    CPDF_Array* pArray = ToArray(pAcroForm->GetObjectFor("XFA"));
+    const CPDF_Array* pArray = ToArray(pAcroForm->GetObjectFor("XFA"));
     if (!pArray)
       return;
 
     int size = pArray->GetCount();
     for (int i = 1; i < size; i += 2) {
-      CPDF_Object* pPDFObj = pArray->GetObjectAt(i);
-      CPDF_Object* pPrePDFObj = pArray->GetObjectAt(i - 1);
+      const CPDF_Object* pPDFObj = pArray->GetObjectAt(i);
+      const CPDF_Object* pPrePDFObj = pArray->GetObjectAt(i - 1);
       if (!pPrePDFObj->IsString())
         continue;
       if (!pPDFObj->IsReference())
         continue;
 
-      CPDF_Stream* pStream = ToStream(pPDFObj->GetDirect());
+      const CPDF_Stream* pStream = ToStream(pPDFObj->GetDirect());
       if (!pStream)
         continue;
       if (pPrePDFObj->GetString() == "form") {
@@ -761,13 +761,13 @@ bool CPDFXFA_DocEnvironment::ExportSubmitFile(FPDF_FILEHANDLER* pFileHandler,
     return false;
   }
 
-  CPDF_Dictionary* pAcroForm = pRoot->GetDictFor("AcroForm");
+  const CPDF_Dictionary* pAcroForm = pRoot->GetDictFor("AcroForm");
   if (!pAcroForm) {
     fileStream->Flush();
     return false;
   }
 
-  CPDF_Array* pArray = ToArray(pAcroForm->GetObjectFor("XFA"));
+  const CPDF_Array* pArray = ToArray(pAcroForm->GetObjectFor("XFA"));
   if (!pArray) {
     fileStream->Flush();
     return false;
@@ -775,32 +775,33 @@ bool CPDFXFA_DocEnvironment::ExportSubmitFile(FPDF_FILEHANDLER* pFileHandler,
 
   int size = pArray->GetCount();
   for (int i = 1; i < size; i += 2) {
-    CPDF_Object* pPDFObj = pArray->GetObjectAt(i);
-    CPDF_Object* pPrePDFObj = pArray->GetObjectAt(i - 1);
+    const CPDF_Object* pPDFObj = pArray->GetObjectAt(i);
+    const CPDF_Object* pPrePDFObj = pArray->GetObjectAt(i - 1);
     if (!pPrePDFObj->IsString())
       continue;
     if (!pPDFObj->IsReference())
       continue;
 
-    CPDF_Object* pDirectObj = pPDFObj->GetDirect();
+    const CPDF_Object* pDirectObj = pPDFObj->GetDirect();
     if (!pDirectObj->IsStream())
       continue;
-    if (pPrePDFObj->GetString() == "config" && !(flag & FXFA_CONFIG))
+    ByteString bsType = pPrePDFObj->GetString();
+    if (bsType == "config" && !(flag & FXFA_CONFIG))
       continue;
-    if (pPrePDFObj->GetString() == "template" && !(flag & FXFA_TEMPLATE))
+    if (bsType == "template" && !(flag & FXFA_TEMPLATE))
       continue;
-    if (pPrePDFObj->GetString() == "localeSet" && !(flag & FXFA_LOCALESET))
+    if (bsType == "localeSet" && !(flag & FXFA_LOCALESET))
       continue;
-    if (pPrePDFObj->GetString() == "datasets" && !(flag & FXFA_DATASETS))
+    if (bsType == "datasets" && !(flag & FXFA_DATASETS))
       continue;
-    if (pPrePDFObj->GetString() == "xmpmeta" && !(flag & FXFA_XMPMETA))
+    if (bsType == "xmpmeta" && !(flag & FXFA_XMPMETA))
       continue;
-    if (pPrePDFObj->GetString() == "xfdf" && !(flag & FXFA_XFDF))
+    if (bsType == "xfdf" && !(flag & FXFA_XFDF))
       continue;
-    if (pPrePDFObj->GetString() == "form" && !(flag & FXFA_FORM))
+    if (bsType == "form" && !(flag & FXFA_FORM))
       continue;
 
-    if (pPrePDFObj->GetString() == "form") {
+    if (bsType == "form") {
       ffdoc->SavePackage(
           ToNode(ffdoc->GetXFADoc()->GetXFAObject(XFA_HASHCODE_Form)),
           fileStream);