Fix / simplify CFX_FolderFontInfo::GetFontData() behavior.

core/src/fxge/ge/fx_ge_fontmap.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 <limits>
 
 #include "../fontdata/chromefontdata/chromefontdata.h"
 #include "core/include/fxge/fx_freetype.h"
 #include "core/include/fxge/fx_ge.h"
 #include "text_int.h"
+#include "third_party/base/stl_util.h"
 
 #define GET_TT_SHORT(w) (FX_WORD)(((w)[0] << 8) | (w)[1])
 #define GET_TT_LONG(w) \
   (FX_DWORD)(((w)[0] << 24) | ((w)[1] << 16) | ((w)[2] << 8) | (w)[3])
 
 #define FX_FONT_STYLE_None 0x00
 #define FX_FONT_STYLE_Bold 0x01
 #define FX_FONT_STYLE_Italic 0x02
 #define FX_FONT_STYLE_BoldBold 0x04
 
@@ skipping 178 matching lines @@
 } g_Codepage2CharsetTable[] = {
     {1, 0},      {2, 42},     {254, 437},  {255, 850},  {222, 874},
     {128, 932},  {134, 936},  {129, 949},  {136, 950},  {238, 1250},
     {204, 1251}, {0, 1252},   {161, 1253}, {162, 1254}, {177, 1255},
     {178, 1256}, {186, 1257}, {163, 1258}, {130, 1361}, {77, 10000},
     {78, 10001}, {79, 10003}, {80, 10008}, {81, 10002}, {83, 10005},
     {84, 10004}, {85, 10006}, {86, 10081}, {87, 10021}, {88, 10029},
     {89, 10007},
 };
 
+const FX_DWORD kTableNAME = FXDWORD_GET_MSBFIRST("name");
+const FX_DWORD kTableTTCF = FXDWORD_GET_MSBFIRST("ttcf");
+
 int CompareFontFamilyString(const void* key, const void* element) {
   CFX_ByteString str_key((const FX_CHAR*)key);
   if (str_key.Find(((AltFontFamily*)element)->m_pFontName) != -1) {
     return 0;
   }
   return FXSYS_stricmp((const FX_CHAR*)key,
                        ((AltFontFamily*)element)->m_pFontName);
 }
 
 int CompareString(const void* key, const void* element) {
@@ skipping 467 matching lines @@
         GET_TT_SHORT(ptr + 2) == 0) {
       return CFX_ByteStringC(string_ptr + GET_TT_SHORT(ptr + 10),
                              GET_TT_SHORT(ptr + 8));
     }
     ptr += 12;
   }
   return CFX_ByteString();
 }
 
 CFX_ByteString CFX_FontMapper::GetPSNameFromTT(void* hFont) {
-  if (m_pFontInfo == NULL) {
+  if (!m_pFontInfo)
     return CFX_ByteString();
-  }
-  CFX_ByteString result;
-  FX_DWORD size = m_pFontInfo->GetFontData(hFont, 0x6e616d65, NULL, 0);
-  if (size) {
-    uint8_t* buffer = FX_Alloc(uint8_t, size);
-    m_pFontInfo->GetFontData(hFont, 0x6e616d65, buffer, size);
-    result = GetNameFromTT(buffer, 6);
-    FX_Free(buffer);
-  }
-  return result;
+
+  FX_DWORD size = m_pFontInfo->GetFontData(hFont, kTableNAME, nullptr, 0);
+  if (!size)
+    return CFX_ByteString();
+
+  std::vector<uint8_t> buffer(size);
+  uint8_t* buffer_ptr = pdfium::vector_as_array(&buffer);
+  FX_DWORD bytes_read =
+      m_pFontInfo->GetFontData(hFont, kTableNAME, buffer_ptr, size);
+  return (bytes_read == size) ? GetNameFromTT(buffer_ptr, 6) : CFX_ByteString();
 }
+
 void CFX_FontMapper::AddInstalledFont(const CFX_ByteString& name, int charset) {
   if (m_pFontInfo == NULL) {
     return;
   }
   if (m_CharsetArray.Find((FX_DWORD)charset) == -1) {
     m_CharsetArray.Add((FX_DWORD)charset);
     m_FaceArray.Add(name);
   }
   if (name == m_LastFamily) {
     return;
@@ skipping 400 matching lines @@
       }
       int index = m_CharsetArray.Find(Charset);
       if (index < 0) {
         return UseInternalSubst(pSubstFont, iBaseFont, italic_angle, old_weight,
                                 PitchFamily);
       }
       hFont = m_pFontInfo->GetFont(m_FaceArray[index]);
     }
   }
   pSubstFont->m_ExtHandle = m_pFontInfo->RetainFont(hFont);
-  if (hFont == NULL) {
-    return NULL;
-  }
+  if (!hFont)
+    return nullptr;
+
   m_pFontInfo->GetFaceName(hFont, SubstName);
   if (Charset == FXFONT_DEFAULT_CHARSET) {
     m_pFontInfo->GetFontCharset(hFont, Charset);
   }
-  FX_DWORD ttc_size = m_pFontInfo->GetFontData(hFont, 0x74746366, NULL, 0);
-  FX_DWORD font_size = m_pFontInfo->GetFontData(hFont, 0, NULL, 0);
+  FX_DWORD ttc_size = m_pFontInfo->GetFontData(hFont, kTableTTCF, nullptr, 0);
+  FX_DWORD font_size = m_pFontInfo->GetFontData(hFont, 0, nullptr, 0);
   if (font_size == 0 && ttc_size == 0) {
     m_pFontInfo->DeleteFont(hFont);
-    return NULL;
+    return nullptr;
   }
-  FXFT_Face face = NULL;
+  FXFT_Face face = nullptr;
   if (ttc_size) {
     uint8_t temp[1024];
-    m_pFontInfo->GetFontData(hFont, 0x74746366, temp, 1024);
+    m_pFontInfo->GetFontData(hFont, kTableTTCF, temp, 1024);
     FX_DWORD checksum = 0;
     for (int i = 0; i < 256; i++) {
       checksum += ((FX_DWORD*)temp)[i];
     }
     uint8_t* pFontData;
     face = m_pFontMgr->GetCachedTTCFace(ttc_size, checksum,
                                         ttc_size - font_size, pFontData);
     if (face == NULL) {
       pFontData = FX_Alloc(uint8_t, ttc_size);
-      m_pFontInfo->GetFontData(hFont, 0x74746366, pFontData, ttc_size);
+      m_pFontInfo->GetFontData(hFont, kTableTTCF, pFontData, ttc_size);
       face = m_pFontMgr->AddCachedTTCFace(ttc_size, checksum, pFontData,
                                           ttc_size, ttc_size - font_size);
     }
   } else {
     uint8_t* pFontData;
     face = m_pFontMgr->GetCachedFace(SubstName, weight, bItalic, pFontData);
     if (face == NULL) {
       pFontData = FX_Alloc(uint8_t, font_size);
       m_pFontInfo->GetFontData(hFont, 0, pFontData, font_size);
       face = m_pFontMgr->AddCachedFace(SubstName, weight, bItalic, pFontData,
@@ skipping 108 matching lines @@
   FXSYS_fseek(pFile, 0, FXSYS_SEEK_END);
   FX_DWORD filesize = FXSYS_ftell(pFile);
   uint8_t buffer[16];
   FXSYS_fseek(pFile, 0, FXSYS_SEEK_SET);
   size_t readCnt = FXSYS_fread(buffer, 12, 1, pFile);
   if (readCnt != 1) {
     FXSYS_fclose(pFile);
     return;
   }
 
-  if (GET_TT_LONG(buffer) == 0x74746366) {
+  if (GET_TT_LONG(buffer) == kTableTTCF) {
     FX_DWORD nFaces = GET_TT_LONG(buffer + 8);
     if (nFaces > std::numeric_limits<FX_DWORD>::max() / 4) {
       FXSYS_fclose(pFile);
       return;
     }
     FX_DWORD face_bytes = nFaces * 4;
     uint8_t* offsets = FX_Alloc(uint8_t, face_bytes);
     readCnt = FXSYS_fread(offsets, 1, face_bytes, pFile);
     if (readCnt != face_bytes) {
       FX_Free(offsets);
@@ skipping 124 matching lines @@
                                   int charset,
                                   int pitch_family,
                                   const FX_CHAR* family,
                                   int& iExact) {
   return NULL;
 }
 void* CFX_FolderFontInfo::GetFont(const FX_CHAR* face) {
   auto it = m_FontList.find(face);
   return it != m_FontList.end() ? it->second : nullptr;
 }
+
 FX_DWORD CFX_FolderFontInfo::GetFontData(void* hFont,
                                          FX_DWORD table,
                                          uint8_t* buffer,
                                          FX_DWORD size) {
-  if (hFont == NULL) {
+  if (!hFont)
     return 0;
-  }
-  CFX_FontFaceInfo* pFont = (CFX_FontFaceInfo*)hFont;
-  FXSYS_FILE* pFile = NULL;
-  if (size > 0) {
-    pFile = FXSYS_fopen(pFont->m_FilePath, "rb");
-    if (pFile == NULL) {
-      return 0;
-    }
-  }
+
+  const CFX_FontFaceInfo* pFont = static_cast<CFX_FontFaceInfo*>(hFont);
   FX_DWORD datasize = 0;
   FX_DWORD offset = 0;
   if (table == 0) {
     datasize = pFont->m_FontOffset ? 0 : pFont->m_FileSize;
-  } else if (table == 0x74746366) {
+  } else if (table == kTableTTCF) {
     datasize = pFont->m_FontOffset ? pFont->m_FileSize : 0;
   } else {
     FX_DWORD nTables = pFont->m_FontTables.GetLength() / 16;
     for (FX_DWORD i = 0; i < nTables; i++) {
-      const uint8_t* p = (const uint8_t*)pFont->m_FontTables + i * 16;
+      const uint8_t* p =
+          static_cast<const uint8_t*>(pFont->m_FontTables) + i * 16;
       if (GET_TT_LONG(p) == table) {
         offset = GET_TT_LONG(p + 8);
         datasize = GET_TT_LONG(p + 12);
       }
     }
   }
-  if (datasize && size >= datasize && pFile) {
-    if (FXSYS_fseek(pFile, offset, FXSYS_SEEK_SET) < 0 ||
-        FXSYS_fread(buffer, datasize, 1, pFile) != 1) {
-      datasize = 0;
-    }
+
+  if (!datasize || size < datasize)
+    return datasize;
+
+  FXSYS_FILE* pFile = FXSYS_fopen(pFont->m_FilePath, "rb");
+  if (!pFile)
+    return 0;
+
+  if (FXSYS_fseek(pFile, offset, FXSYS_SEEK_SET) < 0 ||
+      FXSYS_fread(buffer, datasize, 1, pFile) != 1) {
+    datasize = 0;
   }
-  if (pFile) {
-    FXSYS_fclose(pFile);
-  }
+  FXSYS_fclose(pFile);
   return datasize;
 }
+
 void CFX_FolderFontInfo::DeleteFont(void* hFont) {}
 FX_BOOL CFX_FolderFontInfo::GetFaceName(void* hFont, CFX_ByteString& name) {
   if (hFont == NULL) {
     return FALSE;
   }
   CFX_FontFaceInfo* pFont = (CFX_FontFaceInfo*)hFont;
   name = pFont->m_FaceName;
   return TRUE;
 }
 FX_BOOL CFX_FolderFontInfo::GetFontCharset(void* hFont, int& charset) {
   return FALSE;
 }
 
 int PDF_GetStandardFontName(CFX_ByteString* name) {
   AltFontName* found = static_cast<AltFontName*>(
       FXSYS_bsearch(name->c_str(), g_AltFontNames, FX_ArraySize(g_AltFontNames),
                     sizeof(AltFontName), CompareString));
   if (!found)
     return -1;
 
   *name = g_Base14FontNames[found->m_Index];
   return found->m_Index;
 }