Revert "Revert "Revert "Cleanup some numeric code."""

core/src/fpdfapi/fpdf_font/fpdf_font_cid.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_module.h"
 #include "../../../include/fpdfapi/fpdf_page.h"
 #include "../../../include/fpdfapi/fpdf_resource.h"
-#include "../../../include/fxcrt/fx_ext.h"
 #include "../../../include/fxge/fx_freetype.h"
 #include "../../../include/fxge/fx_ge.h"
 #include "../fpdf_cmaps/cmap_int.h"
 #include "font_int.h"
 
 namespace {
 
 const FX_CHAR* const g_CharsetNames[CIDSET_NUM_SETS] =
     {nullptr, "GB1", "CNS1", "Japan1", "Korea1", "UCS"};
 
@@ skipping 671 matching lines @@
         if (CMap_GetCodeRange(range, m_LastWord, word)) {
           m_CodeRanges.Add(range);
         }
       }
       m_CodeSeq++;
     }
   }
   m_LastWord = word;
 }
 
-// Static.
 FX_DWORD CPDF_CMapParser::CMap_GetCode(const CFX_ByteStringC& word) {
   int num = 0;
   if (word.GetAt(0) == '<') {
-    for (int i = 1; i < word.GetLength() && std::isxdigit(word.GetAt(i)); ++i)
-      num = num * 16 + FXSYS_toHexDigit(word.GetAt(i));
-    return num;
+    for (int i = 1; i < word.GetLength(); i++) {
+      uint8_t digit = word.GetAt(i);
+      if (digit >= '0' && digit <= '9') {
+        digit = digit - '0';
+      } else if (digit >= 'a' && digit <= 'f') {
+        digit = digit - 'a' + 10;
+      } else if (digit >= 'A' && digit <= 'F') {
+        digit = digit - 'A' + 10;
+      } else {
+        return num;
+      }
+      num = num * 16 + digit;
+    }
+  } else {
+    for (int i = 0; i < word.GetLength(); i++) {
+      if (word.GetAt(i) < '0' || word.GetAt(i) > '9') {
+        return num;
+      }
+      num = num * 10 + word.GetAt(i) - '0';
+    }
   }
-
-  for (int i = 0; i < word.GetLength() && std::isdigit(word.GetAt(i)); ++i)
-    num = num * 10 + FXSYS_toDecimalDigit(word.GetAt(i));
   return num;
 }
 
 // Static.
 bool CPDF_CMapParser::CMap_GetCodeRange(CMap_CodeRange& range,
                                         const CFX_ByteStringC& first,
                                         const CFX_ByteStringC& second) {
   if (first.GetLength() == 0 || first.GetAt(0) != '<')
     return false;
 
   int i;
   for (i = 1; i < first.GetLength(); ++i) {
     if (first.GetAt(i) == '>') {
       break;
     }
   }
   range.m_CharSize = (i - 1) / 2;
   if (range.m_CharSize > 4)
     return false;
 
   for (i = 0; i < range.m_CharSize; ++i) {
     uint8_t digit1 = first.GetAt(i * 2 + 1);
     uint8_t digit2 = first.GetAt(i * 2 + 2);
-    range.m_Lower[i] = FXSYS_toHexDigit(digit1) * 16 + FXSYS_toHexDigit(digit2);
+    uint8_t byte = (digit1 >= '0' && digit1 <= '9')
+                       ? (digit1 - '0')
+                       : ((digit1 & 0xdf) - 'A' + 10);
+    byte = byte * 16 + ((digit2 >= '0' && digit2 <= '9')
+                            ? (digit2 - '0')
+                            : ((digit2 & 0xdf) - 'A' + 10));
+    range.m_Lower[i] = byte;
   }
 
   FX_DWORD size = second.GetLength();
   for (i = 0; i < range.m_CharSize; ++i) {
     uint8_t digit1 = ((FX_DWORD)i * 2 + 1 < size)
                          ? second.GetAt((FX_STRSIZE)i * 2 + 1)
                          : '0';
     uint8_t digit2 = ((FX_DWORD)i * 2 + 2 < size)
                          ? second.GetAt((FX_STRSIZE)i * 2 + 2)
                          : '0';
-    range.m_Upper[i] = FXSYS_toHexDigit(digit1) * 16 + FXSYS_toHexDigit(digit2);
+    uint8_t byte = (digit1 >= '0' && digit1 <= '9')
+                       ? (digit1 - '0')
+                       : ((digit1 & 0xdf) - 'A' + 10);
+    byte = byte * 16 + ((digit2 >= '0' && digit2 <= '9')
+                            ? (digit2 - '0')
+                            : ((digit2 & 0xdf) - 'A' + 10));
+    range.m_Upper[i] = byte;
   }
   return true;
 }
 
 CPDF_CMap::CPDF_CMap() {
   m_Charset = CIDSET_UNKNOWN;
   m_Coding = CIDCODING_UNKNOWN;
   m_CodingScheme = TwoBytes;
   m_bVertical = 0;
   m_bLoaded = FALSE;
@@ skipping 963 matching lines @@
 
 const uint8_t* CPDF_CIDFont::GetCIDTransform(FX_WORD CID) const {
   if (m_Charset != CIDSET_JAPAN1 || m_pFontFile)
     return nullptr;
 
   const struct CIDTransform* found = (const struct CIDTransform*)FXSYS_bsearch(
       &CID, g_Japan1_VertCIDs, FX_ArraySize(g_Japan1_VertCIDs),
       sizeof(g_Japan1_VertCIDs[0]), CompareCIDTransform);
   return found ? &found->a : nullptr;
 }