Fix a regression from commit f3e6851.

core/fxge/android/fpf_skiafontmgr.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 "core/fxcrt/include/fx_system.h"
 
 #if _FX_OS_ == _FX_ANDROID_
 
@@ skipping 288 matching lines @@
     if ((dwStyle & FXFONT_SCRIPT) == (pFontDes->m_dwStyle & FXFONT_SCRIPT)) {
       nFind += FPF_SKIAMATCHWEIGHT_2;
     }
     if (dwSubst == dwSysFontName || dwSubstSans == dwSysFontName) {
       nFind += FPF_SKIAMATCHWEIGHT_NAME2;
       bMatchedName = true;
     }
     if (uCharset == FXFONT_DEFAULT_CHARSET || bMaybeSymbol) {
       if (nFind > nMax && bMatchedName) {
         nMax = nFind;
-        nItem = it - m_FontFaces.rbegin();
+        nItem = m_FontFaces.rend() - it - 1;

[olsen, 2016/06/28 00:53:18]

This will work, but it is prone to the same type of bugs as was introduced last
refactoring. Instead of nItem, an integer index or reverse index, consider
keeping a pointer to the best font so far eg:

CFPF_SkiaFontDescriptor* pBestFont;

[Lei Zhang, 2016/06/28 01:11:26]

Done.

       }
     } else if (FPF_SkiaIsCJK(uCharset)) {
       if (bMatchedName || pFontDes->m_iGlyphNum > nGlyphNum) {
-        nItem = it - m_FontFaces.rbegin();
+        nItem = m_FontFaces.rend() - it - 1;
         nGlyphNum = pFontDes->m_iGlyphNum;
       }
     } else if (nFind > nMax) {
       nMax = nFind;
-      nItem = it - m_FontFaces.rbegin();
+      nItem = m_FontFaces.rend() - it - 1;
     }
     if (nExpectVal <= nFind) {
-      nItem = it - m_FontFaces.rbegin();
+      nItem = m_FontFaces.rend() - it - 1;
       break;
     }
   }
   if (nItem > -1) {
     CFPF_SkiaFontDescriptor* pFontDes = m_FontFaces[nItem];
     CFPF_SkiaFont* pFont = new CFPF_SkiaFont;
     if (pFont->InitFont(this, pFontDes, bsFamilyname, dwStyle, uCharset)) {
       m_FamilyFonts[dwHash] = pFont;
       return pFont->Retain();
     }
@@ skipping 181 matching lines @@
   }
   if (pOS2 && (pOS2->ulCodePageRange1 & (1 << 31))) {
     pFontDesc->m_dwStyle |= FXFONT_SYMBOLIC;
   }
   pFontDesc->m_dwCharsets = FPF_SkiaGetFaceCharset(pOS2);
   pFontDesc->m_iFaceIndex = face->face_index;
   pFontDesc->m_iGlyphNum = face->num_glyphs;
 }
 void CFPF_SkiaFontMgr::OutputSystemFonts() {}
 #endif