Transform font size to user space for valid text size comparison.

core/src/fpdftext/fpdf_text_int.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_resource.h"
 #include "../../include/fpdfapi/fpdf_pageobj.h"
 #include "../../include/fpdftext/fpdf_text.h"
 #include "../../include/fpdfapi/fpdf_page.h"
@@ skipping 1826 matching lines @@
         charinfo.m_Matrix.Copy(matrix);
         if (wstrItem.IsEmpty()) {
             charinfo.m_Unicode = 0;
             m_TempCharList.Add(charinfo);
             m_TempTextBuf.AppendChar(0xfffe);
             continue;
         } else {
             int nTotal = wstrItem.GetLength();
             int n = 0;
             FX_BOOL bDel = FALSE;
+            FX_FLOAT threshold = charinfo.m_Matrix.TransformXDistance((FX_FLOAT)TEXT_CHARRATIO_GAPDELTA * pTextObj->GetFontSize());
             while (n < m_TempCharList.GetSize() && n < 7) {
                 n++;
                 PAGECHAR_INFO* charinfo1 = (PAGECHAR_INFO*)m_TempCharList.GetAt(m_TempCharList.GetSize() - n);
                 if(charinfo1->m_CharCode == charinfo.m_CharCode &&
                         charinfo1->m_pTextObj->GetFont() == charinfo.m_pTextObj->GetFont()  &&
-                        FXSYS_fabs(charinfo1->m_OriginX - charinfo.m_OriginX) < TEXT_CHARRATIO_GAPDELTA * pTextObj->GetFontSize()  &&
-                        FXSYS_fabs(charinfo1->m_OriginY - charinfo.m_OriginY) < TEXT_CHARRATIO_GAPDELTA * pTextObj->GetFontSize() ) {
+                        FXSYS_fabs(charinfo1->m_OriginX - charinfo.m_OriginX) < threshold  &&
+                        FXSYS_fabs(charinfo1->m_OriginY - charinfo.m_OriginY) < threshold) {
                     bDel = TRUE;
                     break;
                 }
             }
             if(!bDel) {
                 for (int nIndex = 0; nIndex < nTotal; nIndex++) {
                     charinfo.m_Unicode = wstrItem.GetAt(nIndex);
                     if (charinfo.m_Unicode) {
                         charinfo.m_Index = m_TextBuf.GetLength();
                         m_TempTextBuf.AppendChar(charinfo.m_Unicode);
@@ skipping 984 matching lines @@
     if (!m_IsParserd || index < 0 || index >= m_LinkList.GetSize()) {
         return;
     }
     CPDF_LinkExt* link = NULL;
     link = m_LinkList.GetAt(index);
     if (!link) {
         return ;
     }
     m_pTextPage->GetRectArray(link->m_Start, link->m_Count, rects);
 }