Added abandoned KDE3 version of kdiff3

git-svn-id: svn://anonsvn.kde.org/home/kde/branches/trinity/applications/kdiff3@1088041 283d02a7-25f6-0310-bc7c-ecb5cbfe19da

1 files changed, 1920 insertions, 0 deletions

diff --git a/src/diff.cpp b/src/diff.cpp
new file mode 100644
index 0000000..7875bc6
--- /dev/null
+++ b/src/diff.cpp
@@ -0,0 +1,1920 @@
+/***************************************************************************
+                          diff.cpp  -  description
+                             -------------------
+    begin                : Mon Mar 18 2002
+    copyright            : (C) 2002-2007 by Joachim Eibl
+    email                : joachim.eibl at gmx.de
+ ***************************************************************************/
+
+/***************************************************************************
+ *                                                                         *
+ *   This program is free software; you can redistribute it and/or modify  *
+ *   it under the terms of the GNU General Public License as published by  *
+ *   the Free Software Foundation; either version 2 of the License, or     *
+ *   (at your option) any later version.                                   *
+ *                                                                         *
+ ***************************************************************************/
+
+#include <cstdlib>
+#include <stdio.h>
+#include <iostream>
+
+#include "diff.h"
+#include "fileaccess.h"
+#include "optiondialog.h"
+
+#include <kmessagebox.h>
+#include <klocale.h>
+#include <qfileinfo.h>
+#include <qdir.h>
+#include <qtextcodec.h>
+
+#include <map>
+#include <assert.h>
+#include <ctype.h>
+//using namespace std;
+
+
+int LineData::width(int tabSize) const
+{
+   int w=0;
+   int j=0;
+   for( int i=0; i<size; ++i )
+   {
+      if ( pLine[i]=='\t' )
+      {
+         for(j %= tabSize; j<tabSize; ++j)
+            ++w;
+         j=0;
+      }
+      else
+      {
+         ++w;
+         ++j;
+      }
+   }
+   return w;
+}
+
+
+// The bStrict flag is true during the test where a nonmatching area ends.
+// Then the equal()-function requires that the match has more than 2 nonwhite characters.
+// This is to avoid matches on trivial lines (e.g. with white space only).
+// This choice is good for C/C++.
+bool equal( const LineData& l1, const LineData& l2, bool bStrict )
+{
+   if ( l1.pLine==0 || l2.pLine==0) return false;
+
+   if ( bStrict && g_bIgnoreTrivialMatches )//&& (l1.occurances>=5 || l2.occurances>=5) )
+      return false;
+
+   // Ignore white space diff
+   const QChar* p1 = l1.pLine;
+   const QChar* p1End = p1 + l1.size;
+
+   const QChar* p2 = l2.pLine;
+   const QChar* p2End = p2 + l2.size;
+
+   if ( g_bIgnoreWhiteSpace )
+   {
+      int nonWhite = 0;
+      for(;;)
+      {
+         while( isWhite( *p1 ) && p1!=p1End ) ++p1;
+         while( isWhite( *p2 ) && p2!=p2End ) ++p2;
+
+         if ( p1 == p1End  &&  p2 == p2End )
+         {
+            if ( bStrict && g_bIgnoreTrivialMatches )
+            {  // Then equality is not enough
+               return nonWhite>2;
+            }
+            else  // equality is enough
+               return true;
+         }
+         else if ( p1 == p1End || p2 == p2End )
+            return false;
+
+         if( *p1 != *p2 )
+            return false;
+         ++p1;
+         ++p2;
+         ++nonWhite;
+      }
+   }
+
+   else
+   {
+      if ( l1.size==l2.size && memcmp(p1, p2, l1.size)==0)
+         return true;
+      else
+         return false;
+   }
+}
+
+
+static bool isLineOrBufEnd( const QChar* p, int i, int size )
+{
+   return 
+      i>=size        // End of file
+      || p[i]=='\n'  // Normal end of line
+
+      // No support for Mac-end of line yet, because incompatible with GNU-diff-routines.      
+      // || ( p[i]=='\r' && (i>=size-1 || p[i+1]!='\n') 
+      //                 && (i==0        || p[i-1]!='\n') )  // Special case: '\r' without '\n'
+      ;
+}
+
+
+/* Features of class SourceData:
+- Read a file (from the given URL) or accept data via a string.
+- Allocate and free buffers as necessary.
+- Run a preprocessor, when specified.
+- Run the line-matching preprocessor, when specified.
+- Run other preprocessing steps: Uppercase, ignore comments,
+                                 remove carriage return, ignore numbers.
+
+Order of operation:
+ 1. If data was given via a string then save it to a temp file. (see setData())
+ 2. If the specified file is nonlocal (URL) copy it to a temp file.
+ 3. If a preprocessor was specified, run the input file through it.
+ 4. Read the output of the preprocessor.
+ 5. If Uppercase was specified: Turn the read data to uppercase.
+ 6. Write the result to a temp file.
+ 7. If a line-matching preprocessor was specified, run the temp file through it.
+ 8. Read the output of the line-matching preprocessor.
+ 9. If ignore numbers was specified, strip the LMPP-output of all numbers.
+10. If ignore comments was specified, strip the LMPP-output of comments.
+
+Optimizations: Skip unneeded steps.
+*/
+
+SourceData::SourceData()
+{
+   m_pOptionDialog = 0;
+   reset();
+}
+
+SourceData::~SourceData()
+{
+   reset();
+}
+
+void SourceData::reset()
+{
+   m_pEncoding = 0;
+   m_fileAccess = FileAccess();
+   m_normalData.reset();
+   m_lmppData.reset();
+   if ( !m_tempInputFileName.isEmpty() )
+   {
+      FileAccess::removeFile( m_tempInputFileName );
+      m_tempInputFileName = "";
+   }
+}
+
+void SourceData::setFilename( const QString& filename )
+{
+   if (filename.isEmpty())
+   {
+      reset();
+   }
+   else
+   {
+      FileAccess fa( filename );
+      setFileAccess( fa );
+   }
+}
+
+bool SourceData::isEmpty() 
+{ 
+   return getFilename().isEmpty(); 
+}
+
+bool SourceData::hasData() 
+{ 
+   return m_normalData.m_pBuf != 0;
+}
+
+bool SourceData::isValid()
+{
+   return isEmpty() || hasData();
+}
+
+void SourceData::setOptionDialog( OptionDialog* pOptionDialog )
+{
+   m_pOptionDialog = pOptionDialog;
+}
+
+QString SourceData::getFilename()
+{
+   return m_fileAccess.absFilePath();
+}
+
+QString SourceData::getAliasName()
+{
+   return m_aliasName.isEmpty() ? m_fileAccess.prettyAbsPath() : m_aliasName;
+}
+
+void SourceData::setAliasName( const QString& name )
+{
+   m_aliasName = name;
+}
+
+void SourceData::setFileAccess( const FileAccess& fileAccess )
+{
+   m_fileAccess = fileAccess;
+   m_aliasName = QString();
+   if ( !m_tempInputFileName.isEmpty() )
+   {
+      FileAccess::removeFile( m_tempInputFileName );
+      m_tempInputFileName = "";
+   }
+}
+
+void SourceData::setData( const QString& data )
+{
+   // Create a temp file for preprocessing:
+   if ( m_tempInputFileName.isEmpty() )
+   {
+      m_tempInputFileName = FileAccess::tempFileName();
+   }
+
+   FileAccess f( m_tempInputFileName );
+   bool bSuccess = f.writeFile( QTextCodec::codecForName("UTF-8")->fromUnicode(data), data.length() );
+   if ( !bSuccess )
+   {
+      KMessageBox::error( m_pOptionDialog, i18n("Writing clipboard data to temp file failed.") );
+      return;
+   }
+
+   m_aliasName = i18n("From Clipboard");
+   m_fileAccess = FileAccess("");  // Effect: m_fileAccess.isValid() is false
+}
+
+const LineData* SourceData::getLineDataForDiff() const
+{
+   if ( m_lmppData.m_pBuf==0 )
+      return m_normalData.m_v.size()>0 ? &m_normalData.m_v[0] : 0;
+   else
+      return m_lmppData.m_v.size()>0   ? &m_lmppData.m_v[0]   : 0;
+}
+
+const LineData* SourceData::getLineDataForDisplay() const
+{
+   return m_normalData.m_v.size()>0 ? &m_normalData.m_v[0] : 0;
+}
+
+int  SourceData::getSizeLines() const
+{
+   return m_normalData.m_vSize;
+}
+
+int SourceData::getSizeBytes() const
+{
+   return m_normalData.m_size;
+}
+
+const char* SourceData::getBuf() const
+{
+   return m_normalData.m_pBuf;
+}
+
+bool SourceData::isText()
+{
+   return m_normalData.m_bIsText;
+}
+ 
+bool SourceData::isFromBuffer()
+{
+   return !m_fileAccess.isValid();
+}
+
+
+bool SourceData::isBinaryEqualWith( const SourceData& other ) const
+{
+   return m_fileAccess.exists() && other.m_fileAccess.exists() &&
+          getSizeBytes() == other.getSizeBytes() && 
+          ( getSizeBytes()==0 || memcmp( getBuf(), other.getBuf(), getSizeBytes() )==0 );
+}
+
+void SourceData::FileData::reset()
+{
+   delete[] (char*)m_pBuf;
+   m_pBuf = 0;
+   m_v.clear();
+   m_size = 0;
+   m_vSize = 0;
+   m_bIsText = true;
+}
+
+bool SourceData::FileData::readFile( const QString& filename )
+{
+   reset();
+   if ( filename.isEmpty() )   { return true; }
+
+   FileAccess fa( filename );
+   m_size = fa.sizeForReading();
+   char* pBuf;
+   m_pBuf = pBuf = new char[m_size+100];  // Alloc 100 byte extra: Savety hack, not nice but does no harm.
+                                // Some extra bytes at the end of the buffer are needed by
+                                // the diff algorithm. See also GnuDiff::diff_2_files().
+   bool bSuccess = fa.readFile( pBuf, m_size );
+   if ( !bSuccess )
+   {
+      delete pBuf;
+      m_pBuf = 0;
+      m_size = 0;
+   }
+   return bSuccess;
+}
+
+bool SourceData::saveNormalDataAs( const QString& fileName )
+{
+   return m_normalData.writeFile( fileName );
+}
+
+bool SourceData::FileData::writeFile( const QString& filename )
+{
+   if ( filename.isEmpty() )   { return true; }
+
+   FileAccess fa( filename );
+   bool bSuccess = fa.writeFile(m_pBuf, m_size);
+   return bSuccess;
+}
+
+void SourceData::FileData::copyBufFrom( const FileData& src )
+{
+   reset();
+   char* pBuf;
+   m_size = src.m_size;
+   m_pBuf = pBuf = new char[m_size+100];
+   memcpy( pBuf, src.m_pBuf, m_size );
+}
+
+// Convert the input file from input encoding to output encoding and write it to the output file.
+static bool convertFileEncoding( const QString& fileNameIn, QTextCodec* pCodecIn,
+                                 const QString& fileNameOut, QTextCodec* pCodecOut )
+{
+   QFile in( fileNameIn );
+   if ( ! in.open(IO_ReadOnly ) )
+      return false;
+   QTextStream inStream( &in );
+   inStream.setCodec( pCodecIn );
+   //inStream.setAutoDetectUnicode( false ); //not available in Qt3, will always detect UCS2
+
+   QFile out( fileNameOut );
+   if ( ! out.open( IO_WriteOnly ) )
+      return false;
+   QTextStream outStream( &out );
+   outStream.setCodec( pCodecOut );
+
+   QString data = inStream.read();
+   outStream << data;
+
+   return true;
+}
+
+static QTextCodec* detectEncoding( const char* buf, long size, long& skipBytes )
+{
+   if (size>=2)
+   {
+      skipBytes = 0; // In Qt3 UTF-16LE can only be used if autodetected.
+      if (buf[0]=='\xFF' && buf[1]=='\xFE' )
+         return QTextCodec::codecForName( "ISO-10646-UCS2" );// "UTF-16LE"
+
+      if (buf[0]=='\xFE' && buf[1]=='\xFF' )
+         return QTextCodec::codecForName( "ISO-10646-UCS2" );// "UTF-16BE". Qt3 autodetects the difference but has no name for it.
+   }
+   if (size>=3)
+   {
+      skipBytes = 3;
+      if (buf[0]=='\xEF' && buf[1]=='\xBB' && buf[2]=='\xBF' )
+         return QTextCodec::codecForName( "UTF-8-BOM" );
+   }
+   skipBytes = 0;
+   return 0;
+}
+
+QTextCodec* SourceData::detectEncoding( const QString& fileName, QTextCodec* pFallbackCodec )
+{
+   QFile f(fileName);
+   if ( f.open(IO_ReadOnly) )
+   {
+      char buf[4];
+      long size = f.readBlock( buf, sizeof(buf) );
+      long skipBytes = 0;
+      QTextCodec* pCodec = ::detectEncoding( buf, size, skipBytes );
+      if (pCodec)
+         return pCodec;
+   }
+   return pFallbackCodec;
+}
+
+void SourceData::readAndPreprocess( QTextCodec* pEncoding, bool bAutoDetectUnicode )
+{
+   m_pEncoding = pEncoding;
+   QString fileNameIn1;
+   QString fileNameOut1;
+   QString fileNameIn2;
+   QString fileNameOut2;
+
+   bool bTempFileFromClipboard = !m_fileAccess.isValid();
+
+   // Detect the input for the preprocessing operations
+   if ( !bTempFileFromClipboard )
+   {
+      if ( m_fileAccess.isLocal() )
+      {
+         fileNameIn1 = m_fileAccess.absFilePath();
+      }
+      else    // File is not local: create a temporary local copy:
+      {
+         if ( m_tempInputFileName.isEmpty() )  { m_tempInputFileName = FileAccess::tempFileName(); }
+
+         m_fileAccess.copyFile(m_tempInputFileName);
+         fileNameIn1 = m_tempInputFileName;
+      }
+      if ( bAutoDetectUnicode )
+      {
+         m_pEncoding = detectEncoding( fileNameIn1, pEncoding );
+      }
+   }
+   else // The input was set via setData(), probably from clipboard.
+   {
+      fileNameIn1 = m_tempInputFileName;
+      m_pEncoding = QTextCodec::codecForName("UTF-8");
+   }
+   QTextCodec* pEncoding1 = m_pEncoding;
+   QTextCodec* pEncoding2 = m_pEncoding;
+
+   m_normalData.reset();
+   m_lmppData.reset();
+
+   FileAccess faIn(fileNameIn1);
+   int fileInSize = faIn.size();
+
+   if ( faIn.exists() ) // fileInSize > 0 )
+   {
+
+#ifdef _WIN32
+      QString catCmd = "type";
+      fileNameIn1.replace( '/', "\\" );
+#else
+      QString catCmd = "cat";
+#endif
+
+      // Run the first preprocessor
+      if ( m_pOptionDialog->m_PreProcessorCmd.isEmpty() )
+      {
+         // No preprocessing: Read the file directly:
+         m_normalData.readFile( fileNameIn1 );
+      }
+      else
+      {
+         QString fileNameInPP = fileNameIn1;
+
+         if ( pEncoding1 != m_pOptionDialog->m_pEncodingPP )
+         {
+            // Before running the preprocessor convert to the format that the preprocessor expects.
+            fileNameInPP = FileAccess::tempFileName();
+            pEncoding1 = m_pOptionDialog->m_pEncodingPP;
+            convertFileEncoding( fileNameIn1, pEncoding, fileNameInPP, pEncoding1 );
+         }
+
+         QString ppCmd = m_pOptionDialog->m_PreProcessorCmd;
+         fileNameOut1 = FileAccess::tempFileName();
+         QString cmd = catCmd + " \"" + fileNameInPP + "\" | " + ppCmd  + " >\"" + fileNameOut1+"\"";
+         ::system( encodeString(cmd) );
+         bool bSuccess = m_normalData.readFile( fileNameOut1 );
+         if ( fileInSize >0 && ( !bSuccess || m_normalData.m_size==0 ) )
+         {
+            KMessageBox::error(m_pOptionDialog, 
+               i18n("Preprocessing possibly failed. Check this command:\n\n  %1"
+                  "\n\nThe preprocessing command will be disabled now."
+               ).arg(cmd) );
+            m_pOptionDialog->m_PreProcessorCmd = "";
+            m_normalData.readFile( fileNameIn1 );
+            pEncoding1 = m_pEncoding;
+         }
+         if (fileNameInPP != fileNameIn1)
+         {
+            FileAccess::removeTempFile( fileNameInPP );
+         }
+      }
+
+      // LineMatching Preprocessor
+      if ( ! m_pOptionDialog->m_LineMatchingPreProcessorCmd.isEmpty() )
+      {
+         fileNameIn2 = fileNameOut1.isEmpty() ? fileNameIn1 : fileNameOut1;
+         QString fileNameInPP = fileNameIn2;
+         pEncoding2 = pEncoding1;
+         if ( pEncoding2 != m_pOptionDialog->m_pEncodingPP )
+         {
+            // Before running the preprocessor convert to the format that the preprocessor expects.
+            fileNameInPP = FileAccess::tempFileName();
+            pEncoding2 = m_pOptionDialog->m_pEncodingPP;
+            convertFileEncoding( fileNameIn2, pEncoding1, fileNameInPP, pEncoding2 );
+         }
+
+         QString ppCmd = m_pOptionDialog->m_LineMatchingPreProcessorCmd;
+         fileNameOut2 = FileAccess::tempFileName();
+         QString cmd = catCmd + " \"" + fileNameInPP + "\" | " + ppCmd  + " >\"" + fileNameOut2 + "\"";
+         ::system( encodeString(cmd) );
+         bool bSuccess = m_lmppData.readFile( fileNameOut2 );
+         if ( FileAccess(fileNameIn2).size()>0 && ( !bSuccess || m_lmppData.m_size==0 ) )
+         {
+            KMessageBox::error(m_pOptionDialog, 
+               i18n("The line-matching-preprocessing possibly failed. Check this command:\n\n  %1"
+                    "\n\nThe line-matching-preprocessing command will be disabled now."
+                   ).arg(cmd) );
+            m_pOptionDialog->m_LineMatchingPreProcessorCmd = "";
+            m_lmppData.readFile( fileNameIn2 );
+         }
+         FileAccess::removeTempFile( fileNameOut2 );
+         if (fileNameInPP != fileNameIn2)
+         {
+            FileAccess::removeTempFile( fileNameInPP );
+         }
+      }
+      else if ( m_pOptionDialog->m_bIgnoreComments || m_pOptionDialog->m_bIgnoreCase )
+      {
+         // We need a copy of the normal data.
+         m_lmppData.copyBufFrom( m_normalData );
+      }
+      else
+      {  // We don't need any lmpp data at all.
+         m_lmppData.reset();
+      }
+   }
+
+   m_normalData.preprocess( m_pOptionDialog->m_bPreserveCarriageReturn, pEncoding1 );
+   m_lmppData.preprocess( false, pEncoding2 );
+
+   if ( m_lmppData.m_vSize < m_normalData.m_vSize )
+   {
+      // This probably is the fault of the LMPP-Command, but not worth reporting.
+      m_lmppData.m_v.resize( m_normalData.m_vSize );
+      for(int i=m_lmppData.m_vSize; i<m_normalData.m_vSize; ++i )
+      {  // Set all empty lines to point to the end of the buffer.
+         m_lmppData.m_v[i].pLine = m_lmppData.m_unicodeBuf.unicode()+m_lmppData.m_unicodeBuf.length();
+      }
+
+      m_lmppData.m_vSize = m_normalData.m_vSize;
+   }
+
+   // Internal Preprocessing: Uppercase-conversion   
+   if ( m_pOptionDialog->m_bIgnoreCase )
+   {
+      int i;
+      QChar* pBuf = const_cast<QChar*>(m_lmppData.m_unicodeBuf.unicode());
+      int ucSize = m_lmppData.m_unicodeBuf.length();
+      for(i=0; i<ucSize; ++i)
+      {
+         pBuf[i] = pBuf[i].upper();
+      }
+   }
+
+   // Ignore comments
+   if ( m_pOptionDialog->m_bIgnoreComments )
+   {
+      m_lmppData.removeComments();
+      int vSize = min2(m_normalData.m_vSize, m_lmppData.m_vSize);
+      for(int i=0; i<vSize; ++i )
+      {
+         m_normalData.m_v[i].bContainsPureComment = m_lmppData.m_v[i].bContainsPureComment;
+      }
+   }
+
+   // Remove unneeded temporary files. (A temp file from clipboard must not be deleted.)
+   if ( !bTempFileFromClipboard && !m_tempInputFileName.isEmpty() )
+   {
+      FileAccess::removeTempFile( m_tempInputFileName );
+      m_tempInputFileName = "";
+   }
+
+   if ( !fileNameOut1.isEmpty() )
+   {
+      FileAccess::removeTempFile( fileNameOut1 );
+      fileNameOut1="";
+   }
+}
+
+
+/** Prepare the linedata vector for every input line.*/
+void SourceData::FileData::preprocess( bool bPreserveCR, QTextCodec* pEncoding )
+{
+   //m_unicodeBuf = decodeString( m_pBuf, m_size, eEncoding );
+
+   long skipBytes = 0;
+   QTextCodec* pCodec = ::detectEncoding( m_pBuf, m_size, skipBytes );
+   if ( pCodec != pEncoding )
+      skipBytes=0;
+
+   QByteArray ba;
+   ba.setRawData( m_pBuf+skipBytes, m_size-skipBytes );
+   QTextStream ts( ba, IO_ReadOnly );
+   ts.setCodec( pEncoding);
+   //ts.setAutoDetectUnicode( false );
+   m_unicodeBuf = ts.read();
+   ba.resetRawData( m_pBuf+skipBytes, m_size-skipBytes );
+
+   int ucSize = m_unicodeBuf.length();
+   const QChar* p = m_unicodeBuf.unicode();
+
+   m_bIsText = true;
+   int lines = 1;
+   int i;
+   for( i=0; i<ucSize; ++i )
+   {
+      if ( isLineOrBufEnd(p,i,ucSize) )
+      {
+         ++lines;
+      }
+      if ( p[i]=='\0' )
+      {
+         m_bIsText = false;
+      }
+   }
+
+   m_v.resize( lines+5 );
+   int lineIdx=0;
+   int lineLength=0;
+   bool bNonWhiteFound = false;
+   int whiteLength = 0;
+   for( i=0; i<=ucSize; ++i )
+   {
+      if ( isLineOrBufEnd( p, i, ucSize ) )
+      {
+         m_v[lineIdx].pLine = &p[ i-lineLength ];
+         while ( !bPreserveCR  &&  lineLength>0  &&  m_v[lineIdx].pLine[lineLength-1]=='\r'  )
+         {
+            --lineLength;
+         }
+         m_v[lineIdx].pFirstNonWhiteChar = m_v[lineIdx].pLine + min2(whiteLength,lineLength);
+         m_v[lineIdx].size = lineLength;
+         lineLength = 0;
+         bNonWhiteFound = false;
+         whiteLength = 0;
+         ++lineIdx;
+      }
+      else
+      {
+         ++lineLength;
+
+         if ( ! bNonWhiteFound && isWhite( p[i] ) )
+            ++whiteLength;
+         else
+            bNonWhiteFound = true;
+      }
+   }
+   assert( lineIdx == lines );
+
+   m_vSize = lines;
+}
+
+
+// Must not be entered, when within a comment.
+// Returns either at a newline-character p[i]=='\n' or when i==size.
+// A line that contains only comments is still "white".
+// Comments in white lines must remain, while comments in
+// non-white lines are overwritten with spaces.
+static void checkLineForComments(
+   QChar* p,   // pointer to start of buffer
+   int& i,    // index of current position (in, out)
+   int size,  // size of buffer
+   bool& bWhite,          // false if this line contains nonwhite characters (in, out)
+   bool& bCommentInLine,  // true if any comment is within this line (in, out)
+   bool& bStartsOpenComment  // true if the line ends within an comment (out)
+   )
+{
+   bStartsOpenComment = false;
+   for(; i<size; ++i )
+   {
+      // A single apostroph ' has prio over a double apostroph " (e.g. '"')
+      // (if not in a string)
+      if ( p[i]=='\'' )
+      {
+         bWhite = false;
+         ++i;
+         for( ; !isLineOrBufEnd(p,i,size) && p[i]!='\''; ++i)
+            ;
+         if (p[i]=='\'') ++i;
+      }
+
+      // Strings have priority over comments: e.g. "/* Not a comment, but a string. */"
+      else if ( p[i]=='"' )
+      {
+         bWhite = false;
+         ++i;
+         for( ; !isLineOrBufEnd(p,i,size) && !(p[i]=='"' && p[i-1]!='\\'); ++i)
+            ;
+         if (p[i]=='"') ++i;
+      }
+
+      // C++-comment
+      else if ( p[i]=='/' && i+1<size && p[i+1] =='/' )
+      {
+         int commentStart = i;
+         bCommentInLine = true;
+         i+=2;
+         for( ; !isLineOrBufEnd(p,i,size); ++i)
+            ;
+         if ( !bWhite )
+         {
+            memset( &p[commentStart], ' ', i-commentStart );
+         }
+         return;
+      }
+
+      // C-comment
+      else if ( p[i]=='/' && i+1<size && p[i+1] =='*' )
+      {
+         int commentStart = i;
+         bCommentInLine = true;
+         i+=2;
+         for( ; !isLineOrBufEnd(p,i,size); ++i)
+         {
+            if ( i+1<size && p[i]=='*' && p[i+1]=='/')  // end of the comment
+            {
+               i+=2;
+
+               // More comments in the line?
+               checkLineForComments( p, i, size, bWhite, bCommentInLine, bStartsOpenComment );
+               if ( !bWhite )
+               {
+                  memset( &p[commentStart], ' ', i-commentStart );
+               }
+               return;
+            }
+         }
+         bStartsOpenComment = true;
+         return;
+      }
+
+
+      if ( isLineOrBufEnd(p,i,size) )
+      {
+         return;
+      }
+      else if ( !p[i].isSpace() )
+      {
+         bWhite = false;
+      }
+   }
+}
+
+// Modifies the input data, and replaces C/C++ comments with whitespace
+// when the line contains other data too. If the line contains only
+// a comment or white data, remember this in the flag bContainsPureComment.
+void SourceData::FileData::removeComments()
+{
+   int line=0;
+   QChar* p = const_cast<QChar*>(m_unicodeBuf.unicode());
+   bool bWithinComment=false;
+   int size = m_unicodeBuf.length();
+   for(int i=0; i<size; ++i )
+   {
+//      std::cout << "2        " << std::string(&p[i], m_v[line].size) << std::endl;
+      bool bWhite = true;
+      bool bCommentInLine = false;
+
+      if ( bWithinComment )
+      {
+         int commentStart = i;
+         bCommentInLine = true;
+
+         for( ; !isLineOrBufEnd(p,i,size); ++i)
+         {
+            if ( i+1<size && p[i]=='*' && p[i+1]=='/')  // end of the comment
+            {
+               i+=2;
+
+               // More comments in the line?
+               checkLineForComments( p, i, size, bWhite, bCommentInLine, bWithinComment );
+               if ( !bWhite )
+               {
+                  memset( &p[commentStart], ' ', i-commentStart );
+               }
+               break;
+            }
+         }
+      }
+      else
+      {
+         checkLineForComments( p, i, size, bWhite, bCommentInLine, bWithinComment );
+      }
+
+      // end of line
+      assert( isLineOrBufEnd(p,i,size));
+      m_v[line].bContainsPureComment = bCommentInLine && bWhite;
+/*      std::cout << line << " : " <<
+       ( bCommentInLine ?  "c" : " " ) <<
+       ( bWhite ? "w " : "  ") <<
+       std::string(pLD[line].pLine, pLD[line].size) << std::endl;*/
+
+      ++line;
+   }
+}
+
+
+
+// First step
+void calcDiff3LineListUsingAB(
+   const DiffList* pDiffListAB,
+   Diff3LineList& d3ll
+   )
+{
+   // First make d3ll for AB (from pDiffListAB)
+
+   DiffList::const_iterator i=pDiffListAB->begin();
+   int lineA=0;
+   int lineB=0;
+   Diff d(0,0,0);
+
+   for(;;)
+   {
+      if ( d.nofEquals==0 && d.diff1==0 && d.diff2==0 )
+      {
+         if ( i!=pDiffListAB->end() )
+         {
+            d=*i;
+            ++i;
+         }
+         else
+            break;
+      }
+
+      Diff3Line d3l;
+      if( d.nofEquals>0 )
+      {
+         d3l.bAEqB = true;
+         d3l.lineA = lineA;
+         d3l.lineB = lineB;
+         --d.nofEquals;
+         ++lineA;
+         ++lineB;
+      }
+      else if ( d.diff1>0 && d.diff2>0 )
+      {
+         d3l.lineA = lineA;
+         d3l.lineB = lineB;
+         --d.diff1;
+         --d.diff2;
+         ++lineA;
+         ++lineB;
+      }
+      else if ( d.diff1>0 )
+      {
+         d3l.lineA = lineA;
+         --d.diff1;
+         ++lineA;
+      }
+      else if ( d.diff2>0 )
+      {
+         d3l.lineB = lineB;
+         --d.diff2;
+         ++lineB;
+      }
+
+      d3ll.push_back( d3l );
+   }
+}
+
+
+// Second step
+void calcDiff3LineListUsingAC(
+   const DiffList* pDiffListAC,
+   Diff3LineList& d3ll
+   )
+{
+   ////////////////
+   // Now insert data from C using pDiffListAC
+
+   DiffList::const_iterator i=pDiffListAC->begin();
+   Diff3LineList::iterator i3 = d3ll.begin();
+   int lineA=0;
+   int lineC=0;
+   Diff d(0,0,0);
+
+   for(;;)
+   {
+      if ( d.nofEquals==0 && d.diff1==0 && d.diff2==0 )
+      {
+         if ( i!=pDiffListAC->end() )
+         {
+            d=*i;
+            ++i;
+         }
+         else
+            break;
+      }
+
+      Diff3Line d3l;
+      if( d.nofEquals>0 )
+      {
+         // Find the corresponding lineA
+         while( (*i3).lineA!=lineA )
+            ++i3;
+
+         (*i3).lineC = lineC;
+         (*i3).bAEqC = true;
+         (*i3).bBEqC = (*i3).bAEqB;
+
+         --d.nofEquals;
+         ++lineA;
+         ++lineC;
+         ++i3;
+      }
+      else if ( d.diff1>0 && d.diff2>0 )
+      {
+         d3l.lineC = lineC;
+         d3ll.insert( i3, d3l );
+         --d.diff1;
+         --d.diff2;
+         ++lineA;
+         ++lineC;
+      }
+      else if ( d.diff1>0 )
+      {
+         --d.diff1;
+         ++lineA;
+      }
+      else if ( d.diff2>0 )
+      {
+         d3l.lineC = lineC;
+         d3ll.insert( i3, d3l );
+         --d.diff2;
+         ++lineC;
+      }
+   }
+}
+
+// Third step
+void calcDiff3LineListUsingBC(
+   const DiffList* pDiffListBC,
+   Diff3LineList& d3ll
+   )
+{
+   ////////////////
+   // Now improve the position of data from C using pDiffListBC
+   // If a line from C equals a line from A then it is in the
+   // same Diff3Line already.
+   // If a line from C equals a line from B but not A, this
+   // information will be used here.
+
+   DiffList::const_iterator i=pDiffListBC->begin();
+   Diff3LineList::iterator i3b = d3ll.begin();
+   Diff3LineList::iterator i3c = d3ll.begin();
+   int lineB=0;
+   int lineC=0;
+   Diff d(0,0,0);
+
+   for(;;)
+   {
+      if ( d.nofEquals==0 && d.diff1==0 && d.diff2==0 )
+      {
+         if ( i!=pDiffListBC->end() )
+         {
+            d=*i;
+            ++i;
+         }
+         else
+            break;
+      }
+
+      Diff3Line d3l;
+      if( d.nofEquals>0 )
+      {
+         // Find the corresponding lineB and lineC
+         while( i3b!=d3ll.end() && (*i3b).lineB!=lineB )
+            ++i3b;
+
+         while( i3c!=d3ll.end() && (*i3c).lineC!=lineC )
+            ++i3c;
+
+         assert(i3b!=d3ll.end());
+         assert(i3c!=d3ll.end());
+
+         if ( i3b==i3c )
+         {
+            assert( (*i3b).lineC == lineC );
+            (*i3b).bBEqC = true;
+         }
+         else
+         {
+            // Is it possible to move this line up?
+            // Test if no other B's are used between i3c and i3b
+
+            // First test which is before: i3c or i3b ?
+            Diff3LineList::iterator i3c1 = i3c;
+            Diff3LineList::iterator i3b1 = i3b;
+            while( i3c1!=i3b  &&  i3b1!=i3c )
+            {
+               assert(i3b1!=d3ll.end() || i3c1!=d3ll.end());
+               if( i3c1!=d3ll.end() ) ++i3c1;
+               if( i3b1!=d3ll.end() ) ++i3b1;
+            }
+
+            if( i3c1==i3b  &&  !(*i3b).bAEqB ) // i3c before i3b
+            {
+               Diff3LineList::iterator i3 = i3c;
+               int nofDisturbingLines = 0;
+               while( i3 != i3b && i3!=d3ll.end() )
+               {
+                  if ( (*i3).lineB != -1 )
+                     ++nofDisturbingLines;
+                  ++i3;
+               }
+
+               if ( nofDisturbingLines>0 )//&& nofDisturbingLines < d.nofEquals*d.nofEquals+4 )
+               {
+                  // Move the disturbing lines up, out of sight.
+                  i3 = i3c;
+                  while( i3 != i3b )
+                  {
+                     if ( (*i3).lineB != -1 )
+                     {
+                        Diff3Line d3l;
+                        d3l.lineB = (*i3).lineB;
+                        (*i3).lineB = -1;
+                        (*i3).bAEqB = false;
+                        (*i3).bBEqC = false;
+                        d3ll.insert( i3c, d3l );
+                     }
+                     ++i3;
+                  }
+                  nofDisturbingLines=0;
+               }
+
+               if ( nofDisturbingLines == 0 )
+               {
+                  // Yes, the line from B can be moved.
+                  (*i3b).lineB = -1;   // This might leave an empty line: removed later.
+                  (*i3b).bAEqB = false;
+                  (*i3b).bAEqC = false;
+                  (*i3b).bBEqC = false;
+                  (*i3c).lineB = lineB;
+                  (*i3c).bBEqC = true;
+               }
+            }
+            else if( i3b1==i3c  &&  !(*i3c).bAEqC)
+            {
+               Diff3LineList::iterator i3 = i3b;
+               int nofDisturbingLines = 0;
+               while( i3 != i3c && i3!=d3ll.end() )
+               {
+                  if ( (*i3).lineC != -1 )
+                     ++nofDisturbingLines;
+                  ++i3;
+               }
+
+               if ( nofDisturbingLines>0 )//&& nofDisturbingLines < d.nofEquals*d.nofEquals+4 )
+               {
+                  // Move the disturbing lines up.
+                  i3 = i3b;
+                  while( i3 != i3c )
+                  {
+                     if ( (*i3).lineC != -1 )
+                     {
+                        Diff3Line d3l;
+                        d3l.lineC = (*i3).lineC;
+                        (*i3).lineC = -1;
+                        (*i3).bAEqC = false;
+                        (*i3).bBEqC = false;
+                        d3ll.insert( i3b, d3l );
+                     }
+                     ++i3;
+                  }
+                  nofDisturbingLines=0;
+               }
+
+               if ( nofDisturbingLines == 0 )
+               {
+                  // Yes, the line from C can be moved.
+                  (*i3c).lineC = -1;   // This might leave an empty line: removed later.
+                  (*i3c).bAEqC = false;
+                  (*i3c).bBEqC = false;
+                  (*i3b).lineC = lineC;
+                  (*i3b).bBEqC = true;
+               }
+            }
+         }
+
+         --d.nofEquals;
+         ++lineB;
+         ++lineC;
+         ++i3b;
+         ++i3c;
+      }
+      else if ( d.diff1>0 )
+      {
+         Diff3LineList::iterator i3 = i3b;
+         while( (*i3).lineB!=lineB )
+            ++i3;
+         if( i3 != i3b  &&  (*i3).bAEqB==false )
+         {
+            // Take B from this line and move it up as far as possible
+            d3l.lineB = lineB;
+            d3ll.insert( i3b, d3l );
+            (*i3).lineB = -1;
+         }
+         else
+         {
+            i3b=i3;
+         }
+         --d.diff1;
+         ++lineB;
+         ++i3b;
+
+         if( d.diff2>0 )
+         {
+            --d.diff2;
+            ++lineC;
+         }
+      }
+      else if ( d.diff2>0 )
+      {
+         --d.diff2;
+         ++lineC;
+      }
+   }
+/*
+   Diff3LineList::iterator it = d3ll.begin();
+   int li=0;
+   for( ; it!=d3ll.end(); ++it, ++li )
+   {
+      printf( "%4d %4d %4d %4d  A%c=B A%c=C B%c=C\n",
+         li, (*it).lineA, (*it).lineB, (*it).lineC,
+         (*it).bAEqB ? '=' : '!', (*it).bAEqC ? '=' : '!', (*it).bBEqC ? '=' : '!' );
+   }
+   printf("\n");*/
+}
+
+#ifdef _WIN32
+using ::equal;
+#endif
+
+// Test if the move would pass a barrier. Return true if not.
+static bool isValidMove( ManualDiffHelpList* pManualDiffHelpList, int line1, int line2, int winIdx1, int winIdx2 )
+{
+   if (line1>=0 && line2>=0)
+   {
+      ManualDiffHelpList::const_iterator i;
+      for( i = pManualDiffHelpList->begin(); i!=pManualDiffHelpList->end(); ++i )
+      {
+         const ManualDiffHelpEntry& mdhe = *i;
+
+         // Barrier
+         int l1 = winIdx1 == 1 ? mdhe.lineA1 : winIdx1==2 ? mdhe.lineB1 : mdhe.lineC1 ;
+         int l2 = winIdx2 == 1 ? mdhe.lineA1 : winIdx2==2 ? mdhe.lineB1 : mdhe.lineC1 ;
+
+         if ( l1>=0 && l2>=0 )
+         {
+            if ( line1>=l1 && line2<l2 || line1<l1 && line2>=l2 )
+               return false;
+            l1 = winIdx1 == 1 ? mdhe.lineA2 : winIdx1==2 ? mdhe.lineB2 : mdhe.lineC2 ;
+            l2 = winIdx2 == 1 ? mdhe.lineA2 : winIdx2==2 ? mdhe.lineB2 : mdhe.lineC2 ;
+            ++l1;
+            ++l2;
+            if ( line1>=l1 && line2<l2 || line1<l1 && line2>=l2 )
+               return false;
+         }
+      }
+   }
+   return true; // no barrier passed.
+}
+
+void correctManualDiffAlignment( Diff3LineList& d3ll, ManualDiffHelpList* pManualDiffHelpList )
+{
+   if ( pManualDiffHelpList->empty() )
+      return;
+
+   // If a line appears unaligned in comparison to the manual alignment, correct this.
+
+   ManualDiffHelpList::iterator iMDHL;
+   for( iMDHL =  pManualDiffHelpList->begin(); iMDHL != pManualDiffHelpList->end(); ++iMDHL )
+   {
+      Diff3LineList::iterator i3 = d3ll.begin();
+      int winIdxPreferred = 0;
+      int missingWinIdx = 0;
+      int alignedSum = (iMDHL->lineA1<0?0:1) + (iMDHL->lineB1<0?0:1) + (iMDHL->lineC1<0?0:1);
+      if (alignedSum==2)
+      {
+         // If only A & B are aligned then let C rather be aligned with A
+         // If only A & C are aligned then let B rather be aligned with A
+         // If only B & C are aligned then let A rather be aligned with B
+         missingWinIdx = iMDHL->lineA1<0 ? 1 : (iMDHL->lineB1<0 ? 2 : 3 );
+         winIdxPreferred = missingWinIdx == 1 ? 2 : 1; 
+      }
+      else if (alignedSum<=1)
+      {
+         return;
+      }
+
+      // At the first aligned line, move up the two other lines into new d3ls until the second input is aligned
+      // Then move up the third input until all three lines are aligned.
+      int wi=0;
+      for( ; i3!=d3ll.end(); ++i3 )
+      {
+         for ( wi=1; wi<=3; ++wi )
+         {
+            if ( i3->getLineInFile(wi) >= 0 && iMDHL->firstLine(wi) == i3->getLineInFile(wi) )
+               break;
+         }
+         if ( wi<=3 )
+            break;
+      }
+
+      if (wi>=1 && wi <= 3)
+      {
+         // Found manual alignment for one source
+         Diff3LineList::iterator iDest = i3;
+
+         // Move lines up until the next firstLine is found. Omit wi from move and search.
+         int wi2=0;
+         for( ; i3!=d3ll.end(); ++i3 )
+         {
+            for ( wi2=1; wi2<=3; ++wi2 )
+            {
+               if ( wi!=wi2 && i3->getLineInFile(wi2) >= 0 && iMDHL->firstLine(wi2) == i3->getLineInFile(wi2) )
+                  break;
+            }
+            if (wi2>3)
+            {  // Not yet found
+               // Move both others up
+               Diff3Line d3l;
+               // Move both up
+               if (wi==1) // Move B and C up
+               {
+                  d3l.bBEqC = i3->bBEqC;
+                  d3l.lineB = i3->lineB;
+                  d3l.lineC = i3->lineC;
+                  i3->lineB = -1;
+                  i3->lineC = -1;
+               }
+               if (wi==2) // Move A and C up
+               {
+                  d3l.bAEqC = i3->bAEqC;
+                  d3l.lineA = i3->lineA;
+                  d3l.lineC = i3->lineC;
+                  i3->lineA = -1;
+                  i3->lineC = -1;
+               }
+               if (wi==3) // Move A and B up
+               {
+                  d3l.bAEqB = i3->bAEqB;
+                  d3l.lineA = i3->lineA;
+                  d3l.lineB = i3->lineB;
+                  i3->lineA = -1;
+                  i3->lineB = -1;
+               }
+               i3->bAEqB = false;
+               i3->bAEqC = false;
+               i3->bBEqC = false;
+               d3ll.insert( iDest, d3l );
+            }
+            else 
+            {
+               // align the found line with the line we already have here
+               if ( i3 != iDest )
+               {
+                  if (wi2==1)
+                  {
+                     iDest->lineA = i3->lineA;
+                     i3->lineA = -1;
+                     i3->bAEqB = false;
+                     i3->bAEqC = false;                   
+                  }
+                  else if (wi2==2)
+                  {
+                     iDest->lineB = i3->lineB;
+                     i3->lineB = -1;
+                     i3->bAEqB = false;
+                     i3->bBEqC = false;                   
+                  }
+                  else if (wi2==3)
+                  {
+                     iDest->lineC = i3->lineC;
+                     i3->lineC = -1;
+                     i3->bBEqC = false;
+                     i3->bAEqC = false;                   
+                  }
+               }
+
+               if ( missingWinIdx!=0 )
+               {
+                  for( ; i3!=d3ll.end(); ++i3 )
+                  {
+                     int wi3 = missingWinIdx;
+                     if ( i3->getLineInFile(wi3) >= 0 )
+                     {
+                        // not found, move the line before iDest
+                        Diff3Line d3l;
+                        if ( wi3==1 )
+                        {
+                           if (i3->bAEqB)  // Stop moving lines up if one equal is found.
+                              break;
+                           d3l.lineA = i3->lineA;
+                           i3->lineA = -1;
+                           i3->bAEqB = false;
+                           i3->bAEqC = false;
+                        }
+                        if ( wi3==2 )
+                        {
+                           if (i3->bAEqB)
+                              break;
+                           d3l.lineB = i3->lineB;
+                           i3->lineB = -1;
+                           i3->bAEqB = false;
+                           i3->bBEqC = false;
+                        }
+                        if ( wi3==3 )
+                        {
+                           if (i3->bAEqC)
+                              break;
+                           d3l.lineC = i3->lineC;
+                           i3->lineC = -1;
+                           i3->bAEqC = false;
+                           i3->bBEqC = false;
+                        }
+                        d3ll.insert( iDest, d3l );
+                     }
+                  } // for(), searching for wi3
+               }
+               break;
+            }
+         } // for(), searching for wi2
+      } // if, wi found
+   } // for (iMDHL)
+}
+
+// Fourth step
+void calcDiff3LineListTrim(
+   Diff3LineList& d3ll, const LineData* pldA, const LineData* pldB, const LineData* pldC, ManualDiffHelpList* pManualDiffHelpList
+   )
+{
+   const Diff3Line d3l_empty;
+   d3ll.remove( d3l_empty );
+
+   Diff3LineList::iterator i3 = d3ll.begin();
+   Diff3LineList::iterator i3A = d3ll.begin();
+   Diff3LineList::iterator i3B = d3ll.begin();
+   Diff3LineList::iterator i3C = d3ll.begin();
+
+   int line=0;  // diff3line counters
+   int lineA=0; // 
+   int lineB=0;
+   int lineC=0;
+
+   ManualDiffHelpList::iterator iMDHL = pManualDiffHelpList->begin();
+   // The iterator i3 and the variable line look ahead.
+   // The iterators i3A, i3B, i3C and corresponding lineA, lineB and lineC stop at empty lines, if found.
+   // If possible, then the texts from the look ahead will be moved back to the empty places.
+
+   for( ; i3!=d3ll.end(); ++i3, ++line )
+   {
+      if ( iMDHL!=pManualDiffHelpList->end() )
+      {
+         if ( i3->lineA >= 0 && i3->lineA==iMDHL->lineA1 || 
+              i3->lineB >= 0 && i3->lineB==iMDHL->lineB1 || 
+              i3->lineC >= 0 && i3->lineC==iMDHL->lineC1 )
+         {
+            i3A = i3;
+            i3B = i3;
+            i3C = i3;
+            lineA = line;
+            lineB = line;
+            lineC = line;
+            ++iMDHL;
+         }
+      }
+
+      if( line>lineA && (*i3).lineA != -1 && (*i3A).lineB!=-1 && (*i3A).bBEqC  &&
+          ::equal( pldA[(*i3).lineA], pldB[(*i3A).lineB], false ) &&
+          isValidMove( pManualDiffHelpList, (*i3).lineA, (*i3A).lineB, 1, 2 ) &&
+          isValidMove( pManualDiffHelpList, (*i3).lineA, (*i3A).lineC, 1, 3 ) )
+      {
+         // Empty space for A. A matches B and C in the empty line. Move it up.
+         (*i3A).lineA = (*i3).lineA;
+         (*i3A).bAEqB = true;
+         (*i3A).bAEqC = true;
+         (*i3).lineA = -1;
+         (*i3).bAEqB = false;
+         (*i3).bAEqC = false;
+         ++i3A;
+         ++lineA;
+      }
+
+      if( line>lineB && (*i3).lineB != -1 && (*i3B).lineA!=-1 && (*i3B).bAEqC  &&
+          ::equal( pldB[(*i3).lineB], pldA[(*i3B).lineA], false ) &&
+          isValidMove( pManualDiffHelpList, (*i3).lineB, (*i3B).lineA, 2, 1 ) &&
+          isValidMove( pManualDiffHelpList, (*i3).lineB, (*i3B).lineC, 2, 3 ) )
+      {
+         // Empty space for B. B matches A and C in the empty line. Move it up.
+         (*i3B).lineB = (*i3).lineB;
+         (*i3B).bAEqB = true;
+         (*i3B).bBEqC = true;
+         (*i3).lineB = -1;
+         (*i3).bAEqB = false;
+         (*i3).bBEqC = false;
+         ++i3B;
+         ++lineB;
+      }
+
+      if( line>lineC && (*i3).lineC != -1 && (*i3C).lineA!=-1 && (*i3C).bAEqB  &&
+          ::equal( pldC[(*i3).lineC], pldA[(*i3C).lineA], false )&&
+          isValidMove( pManualDiffHelpList, (*i3).lineC, (*i3C).lineA, 3, 1 ) &&
+          isValidMove( pManualDiffHelpList, (*i3).lineC, (*i3C).lineB, 3, 2 ) )
+      {
+         // Empty space for C. C matches A and B in the empty line. Move it up.
+         (*i3C).lineC = (*i3).lineC;
+         (*i3C).bAEqC = true;
+         (*i3C).bBEqC = true;
+         (*i3).lineC = -1;
+         (*i3).bAEqC = false;
+         (*i3).bBEqC = false;
+         ++i3C;
+         ++lineC;
+      }
+
+      if( line>lineA && (*i3).lineA != -1 && !(*i3).bAEqB && !(*i3).bAEqC && 
+          isValidMove( pManualDiffHelpList, (*i3).lineA, (*i3A).lineB, 1, 2 ) &&
+          isValidMove( pManualDiffHelpList, (*i3).lineA, (*i3A).lineC, 1, 3 ) )      {
+         // Empty space for A. A doesn't match B or C. Move it up.
+         (*i3A).lineA = (*i3).lineA;
+         (*i3).lineA = -1;
+         ++i3A;
+         ++lineA;
+      }
+
+      if( line>lineB && (*i3).lineB != -1 && !(*i3).bAEqB && !(*i3).bBEqC  &&
+          isValidMove( pManualDiffHelpList, (*i3).lineB, (*i3B).lineA, 2, 1 ) &&
+          isValidMove( pManualDiffHelpList, (*i3).lineB, (*i3B).lineC, 2, 3 ) )
+      {
+         // Empty space for B. B matches neither A nor C. Move B up.
+         (*i3B).lineB = (*i3).lineB;
+         (*i3).lineB = -1;
+         ++i3B;
+         ++lineB;
+      }
+
+      if( line>lineC && (*i3).lineC != -1 && !(*i3).bAEqC && !(*i3).bBEqC &&
+          isValidMove( pManualDiffHelpList, (*i3).lineC, (*i3C).lineA, 3, 1 ) &&
+          isValidMove( pManualDiffHelpList, (*i3).lineC, (*i3C).lineB, 3, 2 ) )
+      {
+         // Empty space for C. C matches neither A nor B. Move C up.
+         (*i3C).lineC = (*i3).lineC;
+         (*i3).lineC = -1;
+         ++i3C;
+         ++lineC;
+      }
+
+      if( line>lineA && line>lineB && (*i3).lineA != -1 && (*i3).bAEqB && !(*i3).bAEqC )
+      {
+         // Empty space for A and B. A matches B, but not C. Move A & B up.
+         Diff3LineList::iterator i = lineA > lineB ? i3A   : i3B;
+         int                     l = lineA > lineB ? lineA : lineB;
+
+         if ( isValidMove( pManualDiffHelpList, i->lineC, (*i3).lineA, 3, 1 ) &&
+              isValidMove( pManualDiffHelpList, i->lineC, (*i3).lineB, 3, 2 ) )
+         {
+            (*i).lineA = (*i3).lineA;
+            (*i).lineB = (*i3).lineB;
+            (*i).bAEqB = true;
+
+            (*i3).lineA = -1;
+            (*i3).lineB = -1;
+            (*i3).bAEqB = false;
+            i3A = i;
+            i3B = i;
+            ++i3A;
+            ++i3B;
+            lineA=l+1;
+            lineB=l+1;
+         }
+      }
+      else if( line>lineA && line>lineC && (*i3).lineA != -1 && (*i3).bAEqC && !(*i3).bAEqB )
+      {
+         // Empty space for A and C. A matches C, but not B. Move A & C up.
+         Diff3LineList::iterator i = lineA > lineC ? i3A   : i3C;
+         int                     l = lineA > lineC ? lineA : lineC;
+
+         if ( isValidMove( pManualDiffHelpList, i->lineB, (*i3).lineA, 2, 1 ) &&
+              isValidMove( pManualDiffHelpList, i->lineB, (*i3).lineC, 2, 3 ) )
+         {
+            (*i).lineA = (*i3).lineA;
+            (*i).lineC = (*i3).lineC;
+            (*i).bAEqC = true;
+
+            (*i3).lineA = -1;
+            (*i3).lineC = -1;
+            (*i3).bAEqC = false;
+            i3A = i;
+            i3C = i;
+            ++i3A;
+            ++i3C;
+            lineA=l+1;
+            lineC=l+1;
+         }
+      }
+      else if( line>lineB && line>lineC && (*i3).lineB != -1 && (*i3).bBEqC && !(*i3).bAEqC )
+      {
+         // Empty space for B and C. B matches C, but not A. Move B & C up.
+         Diff3LineList::iterator i = lineB > lineC ? i3B   : i3C;
+         int                     l = lineB > lineC ? lineB : lineC;
+
+         if ( isValidMove( pManualDiffHelpList, i->lineA, (*i3).lineB, 1, 2 ) &&
+              isValidMove( pManualDiffHelpList, i->lineA, (*i3).lineC, 1, 3 ) )
+         {
+            (*i).lineB = (*i3).lineB;
+            (*i).lineC = (*i3).lineC;
+            (*i).bBEqC = true;
+
+            (*i3).lineB = -1;
+            (*i3).lineC = -1;
+            (*i3).bBEqC = false;
+            i3B = i;
+            i3C = i;
+            ++i3B;
+            ++i3C;
+            lineB=l+1;
+            lineC=l+1;
+         }
+      }
+
+      if ( (*i3).lineA != -1 )
+      {
+         lineA = line+1;
+         i3A = i3;
+         ++i3A;
+      }
+      if ( (*i3).lineB != -1 )
+      {
+         lineB = line+1;
+         i3B = i3;
+         ++i3B;
+      }
+      if ( (*i3).lineC != -1 )
+      {
+         lineC = line+1;
+         i3C = i3;
+         ++i3C;
+      }
+   }
+
+   d3ll.remove( d3l_empty );
+
+/*
+
+   Diff3LineList::iterator it = d3ll.begin();
+   int li=0;
+   for( ; it!=d3ll.end(); ++it, ++li )
+   {
+      printf( "%4d %4d %4d %4d  A%c=B A%c=C B%c=C\n",
+         li, (*it).lineA, (*it).lineB, (*it).lineC,
+         (*it).bAEqB ? '=' : '!', (*it).bAEqC ? '=' : '!', (*it).bBEqC ? '=' : '!' );
+
+   }
+*/
+}
+
+void DiffBufferInfo::init( Diff3LineList* pD3ll, const Diff3LineVector* pD3lv,
+   const LineData* pldA, int sizeA, const LineData* pldB, int sizeB, const LineData* pldC, int sizeC )
+{
+   m_pDiff3LineList = pD3ll;
+   m_pDiff3LineVector = pD3lv;
+   m_pLineDataA = pldA;
+   m_pLineDataB = pldB;
+   m_pLineDataC = pldC;
+   m_sizeA = sizeA;
+   m_sizeB = sizeB;
+   m_sizeC = sizeC;
+   Diff3LineList::iterator i3 = pD3ll->begin();
+   for( ; i3!=pD3ll->end(); ++i3 )
+   {
+      i3->m_pDiffBufferInfo = this;
+   }
+}
+
+void calcWhiteDiff3Lines(
+   Diff3LineList& d3ll, const LineData* pldA, const LineData* pldB, const LineData* pldC
+   )
+{
+   Diff3LineList::iterator i3 = d3ll.begin();
+
+   for( ; i3!=d3ll.end(); ++i3 )
+   {
+      i3->bWhiteLineA = ( (*i3).lineA == -1  ||  pldA==0 ||  pldA[(*i3).lineA].whiteLine() || pldA[(*i3).lineA].bContainsPureComment );
+      i3->bWhiteLineB = ( (*i3).lineB == -1  ||  pldB==0 ||  pldB[(*i3).lineB].whiteLine() || pldB[(*i3).lineB].bContainsPureComment );
+      i3->bWhiteLineC = ( (*i3).lineC == -1  ||  pldC==0 ||  pldC[(*i3).lineC].whiteLine() || pldC[(*i3).lineC].bContainsPureComment );
+   }
+}
+
+// Just make sure that all input lines are in the output too, exactly once.
+void debugLineCheck( Diff3LineList& d3ll, int size, int idx )
+{
+   Diff3LineList::iterator it = d3ll.begin();
+   int i=0;
+
+   for ( it = d3ll.begin(); it!= d3ll.end(); ++it )
+   {
+      int l=0;
+      if      (idx==1) l=(*it).lineA;
+      else if (idx==2) l=(*it).lineB;
+      else if (idx==3) l=(*it).lineC;
+      else assert(false);
+
+      if ( l!=-1 )
+      {
+         if( l!=i )
+         {
+            KMessageBox::error(0, i18n(
+               "Data loss error:\n"
+               "If it is reproducable please contact the author.\n"
+               ), i18n("Severe Internal Error") );
+            assert(false);
+            std::cerr << "Severe Internal Error.\n";
+            ::exit(-1);
+         }
+         ++i;
+      }
+   }
+
+   if( size!=i )
+   {
+      KMessageBox::error(0, i18n(
+         "Data loss error:\n"
+         "If it is reproducable please contact the author.\n"
+         ), i18n("Severe Internal Error") );
+      assert(false);
+      std::cerr << "Severe Internal Error.\n";
+      ::exit(-1);
+   }
+}
+
+inline bool equal( QChar c1, QChar c2, bool /*bStrict*/ )
+{
+   // If bStrict then white space doesn't match
+
+   //if ( bStrict &&  ( c1==' ' || c1=='\t' ) )
+   //   return false;
+
+   return c1==c2;
+}
+
+
+// My own diff-invention:
+template <class T>
+void calcDiff( const T* p1, int size1, const T* p2, int size2, DiffList& diffList, int match, int maxSearchRange )
+{
+   diffList.clear();
+
+   const T* p1start = p1;
+   const T* p2start = p2;
+   const T* p1end=p1+size1;
+   const T* p2end=p2+size2;
+   for(;;)
+   {
+      int nofEquals = 0;
+      while( p1!=p1end &&  p2!=p2end && equal(*p1, *p2, false) )
+      {
+         ++p1;
+         ++p2;
+         ++nofEquals;
+      }
+
+      bool bBestValid=false;
+      int bestI1=0;
+      int bestI2=0;
+      int i1=0;
+      int i2=0;
+      for( i1=0; ; ++i1 )
+      {
+         if ( &p1[i1]==p1end || ( bBestValid && i1>= bestI1+bestI2))
+         {
+            break;
+         }
+         for(i2=0;i2<maxSearchRange;++i2)
+         {
+            if( &p2[i2]==p2end ||  ( bBestValid && i1+i2>=bestI1+bestI2) )
+            {
+               break;
+            }
+            else if(  equal( p2[i2], p1[i1], true ) &&
+                      ( match==1 ||  abs(i1-i2)<3  || ( &p2[i2+1]==p2end  &&  &p1[i1+1]==p1end ) ||
+                         ( &p2[i2+1]!=p2end  &&  &p1[i1+1]!=p1end  && equal( p2[i2+1], p1[i1+1], false ))
+                      )
+                   )
+            {
+               if ( i1+i2 < bestI1+bestI2 || bBestValid==false )
+               {
+                  bestI1 = i1;
+                  bestI2 = i2;
+                  bBestValid = true;
+                  break;
+               }
+            }
+         }
+      }
+
+      // The match was found using the strict search. Go back if there are non-strict
+      // matches.
+      while( bestI1>=1 && bestI2>=1 && equal( p1[bestI1-1], p2[bestI2-1], false ) )
+      {
+         --bestI1;
+         --bestI2;
+      }
+
+
+      bool bEndReached = false;
+      if (bBestValid)
+      {
+         // continue somehow
+         Diff d(nofEquals, bestI1, bestI2);
+         diffList.push_back( d );
+
+         p1 += bestI1;
+         p2 += bestI2;
+      }
+      else
+      {
+         // Nothing else to match.
+         Diff d(nofEquals, p1end-p1, p2end-p2);
+         diffList.push_back( d );
+
+         bEndReached = true; //break;
+      }
+
+      // Sometimes the algorithm that chooses the first match unfortunately chooses
+      // a match where later actually equal parts don't match anymore.
+      // A different match could be achieved, if we start at the end.
+      // Do it, if it would be a better match.
+      int nofUnmatched = 0;
+      const T* pu1 = p1-1;
+      const T* pu2 = p2-1;
+      while ( pu1>=p1start && pu2>=p2start && equal( *pu1, *pu2, false ) )
+      {
+         ++nofUnmatched;
+         --pu1;
+         --pu2;
+      }
+
+      Diff d = diffList.back();
+      if ( nofUnmatched > 0 )
+      {
+         // We want to go backwards the nofUnmatched elements and redo
+         // the matching
+         d = diffList.back();
+         Diff origBack = d;
+         diffList.pop_back();
+
+         while (  nofUnmatched > 0 )
+         {
+            if ( d.diff1 > 0  &&  d.diff2 > 0 )
+            {
+               --d.diff1;
+               --d.diff2;
+               --nofUnmatched;
+            }
+            else if ( d.nofEquals > 0 )
+            {
+               --d.nofEquals;
+               --nofUnmatched;
+            }
+
+            if ( d.nofEquals==0 && (d.diff1==0 || d.diff2==0) &&  nofUnmatched>0 )
+            {
+               if ( diffList.empty() )
+                  break;
+               d.nofEquals += diffList.back().nofEquals;
+               d.diff1 += diffList.back().diff1;
+               d.diff2 += diffList.back().diff2;
+               diffList.pop_back();
+               bEndReached = false;
+            }
+         }
+
+         if ( bEndReached )
+            diffList.push_back( origBack );
+         else
+         {
+
+            p1 = pu1 + 1 + nofUnmatched;
+            p2 = pu2 + 1 + nofUnmatched;
+            diffList.push_back( d );
+         }
+      }
+      if ( bEndReached )
+         break;
+   }
+
+#ifndef NDEBUG
+   // Verify difflist
+   {
+      int l1=0;
+      int l2=0;
+      DiffList::iterator i;
+      for( i = diffList.begin(); i!=diffList.end(); ++i )
+      {
+         l1+= i->nofEquals + i->diff1;
+         l2+= i->nofEquals + i->diff2;
+      }
+
+      //if( l1!=p1-p1start || l2!=p2-p2start )
+      if( l1!=size1 || l2!=size2 )
+         assert( false );
+   }
+#endif
+}
+
+void fineDiff(
+   Diff3LineList& diff3LineList,
+   int selector,
+   const LineData* v1,
+   const LineData* v2,
+   bool& bTextsTotalEqual
+   )
+{
+   // Finetuning: Diff each line with deltas
+   ProgressProxy pp;
+   int maxSearchLength=500;
+   Diff3LineList::iterator i;
+   int k1=0;
+   int k2=0;
+   bTextsTotalEqual = true;
+   int listSize = diff3LineList.size();
+   int listIdx = 0;
+   for( i= diff3LineList.begin(); i!= diff3LineList.end(); ++i)
+   {
+      if      (selector==1){ k1=i->lineA; k2=i->lineB; }
+      else if (selector==2){ k1=i->lineB; k2=i->lineC; }
+      else if (selector==3){ k1=i->lineC; k2=i->lineA; }
+      else assert(false);
+      if( k1==-1 && k2!=-1  ||  k1!=-1 && k2==-1 ) bTextsTotalEqual=false;
+      if( k1!=-1 && k2!=-1 )
+      {
+         if ( v1[k1].size != v2[k2].size || memcmp( v1[k1].pLine, v2[k2].pLine, v1[k1].size<<1)!=0 )
+         {
+            bTextsTotalEqual = false;
+            DiffList* pDiffList = new DiffList;
+            calcDiff( v1[k1].pLine, v1[k1].size, v2[k2].pLine, v2[k2].size, *pDiffList, 2, maxSearchLength );
+
+            // Optimize the diff list.
+            DiffList::iterator dli;
+            bool bUsefulFineDiff = false;
+            for( dli = pDiffList->begin(); dli!=pDiffList->end(); ++dli)
+            {
+               if( dli->nofEquals >= 4 )
+               {
+                  bUsefulFineDiff = true;
+                  break;
+               }
+            }
+
+            for( dli = pDiffList->begin(); dli!=pDiffList->end(); ++dli)
+            {
+               if( dli->nofEquals < 4  &&  (dli->diff1>0 || dli->diff2>0) 
+                  && !( bUsefulFineDiff && dli==pDiffList->begin() )
+               )
+               {
+                  dli->diff1 += dli->nofEquals;
+                  dli->diff2 += dli->nofEquals;
+                  dli->nofEquals = 0;
+               }
+            }
+
+            if      (selector==1){ delete (*i).pFineAB; (*i).pFineAB = pDiffList; }
+            else if (selector==2){ delete (*i).pFineBC; (*i).pFineBC = pDiffList; }
+            else if (selector==3){ delete (*i).pFineCA; (*i).pFineCA = pDiffList; }
+            else assert(false);
+         }
+
+         if ( (v1[k1].bContainsPureComment || v1[k1].whiteLine()) && (v2[k2].bContainsPureComment || v2[k2].whiteLine()))
+         {
+            if      (selector==1){ i->bAEqB = true; }
+            else if (selector==2){ i->bBEqC = true; }
+            else if (selector==3){ i->bAEqC = true; }
+            else assert(false);
+         }
+      }
+      ++listIdx;
+      pp.setCurrent(double(listIdx)/listSize);
+   }
+}
+
+
+// Convert the list to a vector of pointers
+void calcDiff3LineVector( Diff3LineList& d3ll, Diff3LineVector& d3lv )
+{
+   d3lv.resize( d3ll.size() );
+   Diff3LineList::iterator i;
+   int j=0;
+   for( i= d3ll.begin(); i!= d3ll.end(); ++i, ++j)
+   {
+      d3lv[j] = &(*i);
+   }
+   assert( j==(int)d3lv.size() );
+}
+
+