diff --git a/Src/Common/UnicodeString.cpp b/Src/Common/UnicodeString.cpp
index 7b6c8fd27ef..04f609a3a05 100644
--- a/Src/Common/UnicodeString.cpp
+++ b/Src/Common/UnicodeString.cpp
@@ -103,7 +103,7 @@ String to_charstr(TCHAR ch)
  * This function searches for a string inside another string an if found,
  * replaces it with another string. Function can replace several instances
  * of the string inside one string.
- * @param [in] target A string containing another string to replace.
+ * @param [in,out] target A string containing another string to replace.
  * @param [in] find A string to search and replace with another (@p replace).
  * @param [in] replace A string used to replace original (@p find).
  */
@@ -119,6 +119,27 @@ void replace(String &target, const String &find, const String &replace)
 	}
 }
 
+/**
+ * @brief Replace the characters that matche characters specified in its arguments
+ * @param [in,out] str - A string containing another string to replace.
+ * @param [in] chars - characters to search for
+ * @param [in] rep - String to replace
+ */
+void replace_chars(String& str, const TCHAR* chars, const TCHAR *rep)
+{
+	String::size_type pos = 0;
+	size_t replen = _tcslen(rep);
+	while ((pos = str.find_first_of(chars, pos)) != std::string::npos)
+	{
+		std::string::size_type posend = str.find_first_not_of(chars, pos);
+		if (posend != String::npos)
+			str.replace(pos, posend - pos, rep);
+		else
+			str.replace(pos, str.length() - pos, rep);
+		pos += replen;
+	}
+}
+
 /**
  * @brief Compare two strings ignoring the character casing.
  * @param [in] str1 First string to compare.
diff --git a/Src/Common/UnicodeString.h b/Src/Common/UnicodeString.h
index a4426a90a2d..b9f72070130 100644
--- a/Src/Common/UnicodeString.h
+++ b/Src/Common/UnicodeString.h
@@ -34,6 +34,7 @@ TCHAR from_charstr(const String& str);
 String to_charstr(TCHAR ch);
 
 void replace(String &target, const String &find, const String &replace);
+void replace_chars(String& str, const TCHAR* chars, const TCHAR* rep);
 
 // Comparing
 int compare_nocase(const String &str1, const String &str2);
diff --git a/Src/DiffWrapper.cpp b/Src/DiffWrapper.cpp
index 0debf5af60f..6ba0f8e692c 100644
--- a/Src/DiffWrapper.cpp
+++ b/Src/DiffWrapper.cpp
@@ -305,7 +305,7 @@ static void ReplaceSpaces(std::string & str, const char *rep)
 		if (posend != String::npos)
 			str.replace(pos, posend - pos, rep);
 		else
-			str.replace(pos, 1, rep);
+			str.replace(pos, str.length() - pos, rep);
 		pos += replen;
 	}
 }
@@ -325,7 +325,7 @@ static void ReplaceNumbers(std::string& str, const char* rep)
 		if (posend != String::npos)
 			str.replace(pos, posend - pos, rep);
 		else
-			str.replace(pos, 1, rep);
+			str.replace(pos, str.length() - pos, rep);
 		pos += replen;
 	}
 }
diff --git a/Src/MergeDoc.cpp b/Src/MergeDoc.cpp
index 74a70099222..dcf542e8680 100644
--- a/Src/MergeDoc.cpp
+++ b/Src/MergeDoc.cpp
@@ -538,8 +538,13 @@ int CMergeDoc::Rescan(bool &bBinary, IDENTLEVEL &identical,
 			m_ptBuf[nBuffer]->prepareForRescan();
 
 		// Divide diff blocks to match lines.
-		if (GetOptionsMgr()->GetBool(OPT_CMP_MATCH_SIMILAR_LINES) && m_nBuffers < 3)
-			AdjustDiffBlocks();
+		if (GetOptionsMgr()->GetBool(OPT_CMP_MATCH_SIMILAR_LINES))
+		{
+			if (m_nBuffers < 3)
+				AdjustDiffBlocks();
+			else
+				AdjustDiffBlocks3way();
+		}
 
 		// Analyse diff-list (updating real line-numbers)
 		// this operation does not change the modified flag
diff --git a/Src/MergeDoc.h b/Src/MergeDoc.h
index 507cf9c4071..afa81345a45 100644
--- a/Src/MergeDoc.h
+++ b/Src/MergeDoc.h
@@ -269,7 +269,7 @@ class CMergeDoc : public CDocument, public IMergeDoc
 	void AddToSubstitutionFilters(CMergeEditView* pView, bool bReversed = false);
 	std::vector<WordDiff> GetWordDiffArrayInDiffBlock(int nDiff);
 	std::vector<WordDiff> GetWordDiffArray(int nLineIndex);
-	std::vector<WordDiff> GetWordDiffArrayInRange(const int begin[3], const int end[3]);
+	std::vector<WordDiff> GetWordDiffArrayInRange(const int begin[3], const int end[3], int pane1 = -1, int pane2 = -1);
 	void ClearWordDiffCache(int nDiff = -1);
 private:
 	void Computelinediff(CMergeEditView *pView, CRect rc[], bool bReversed);
@@ -431,8 +431,13 @@ class CMergeDoc : public CDocument, public IMergeDoc
 	void PrimeTextBuffers();
 	void HideLines();
 	void AdjustDiffBlocks();
-	void AdjustDiffBlock(DiffMap & diffmap, const DIFFRANGE & diffrange, const std::vector<WordDiff>& worddiffs, int lo0, int hi0, int lo1, int hi1);
-	int GetMatchCost(int line0, int line1, const std::vector<WordDiff>& worddiffs);
+	void AdjustDiffBlocks3way();
+	void AdjustDiffBlock(DiffMap & diffmap, const DIFFRANGE & diffrange,
+		const std::vector<WordDiff>& worddiffs,
+		int i0, int i1, int lo0, int hi0, int lo1, int hi1);
+	int GetMatchCost(const DIFFRANGE& dr, int i0, int i1, int line0, int line1, const std::vector<WordDiff>& worddiffs);
+	OP_TYPE ComputeOpType3way(const std::vector<std::array<int, 3>>& vlines, size_t index,
+		const DIFFRANGE& diffrange, const DIFFOPTIONS& diffOptions);
 	void FlagTrivialLines();
 	void FlagMovedLines();
 	String GetFileExt(LPCTSTR sFileName, LPCTSTR sDescription) const;
diff --git a/Src/MergeDocDiffSync.cpp b/Src/MergeDocDiffSync.cpp
index 445cc747b5b..939bbdd0e63 100644
--- a/Src/MergeDocDiffSync.cpp
+++ b/Src/MergeDocDiffSync.cpp
@@ -19,6 +19,287 @@
 
 using std::vector;
 
+static void
+ValidateDiffMap(const DiffMap& diffmap)
+{
+	for (const auto& line : diffmap.m_map)
+		assert(line != DiffMap::BAD_MAP_ENTRY);
+}
+
+template <int npanes>
+static void
+ValidateVirtualLineToRealLineMap(
+	const std::vector<std::array<int, npanes>>& vlines,
+	const std::array<int, npanes>& nlines)
+{
+	int line[npanes]{};
+	for (const auto& v : vlines)
+	{
+		for (int pane = 0; pane < npanes; ++pane)
+		{
+			if (v[pane] != DiffMap::GHOST_MAP_ENTRY)
+			{
+				assert(line[pane] == v[pane]);
+				++line[pane];
+			}
+		}
+	}
+	for (int pane = 0; pane < npanes; ++pane)
+		assert(line[pane] == nlines[pane]);
+}
+
+template <int npanes>
+static void 
+PrintVirtualLineToRealLineMap(
+	const String& name,
+	const std::vector<std::array<int, npanes>>& vlines)
+{
+	OutputDebugString((_T("[") + name + _T("]\n")).c_str());
+	for (size_t i = 0; i < vlines.size(); ++i)
+	{
+		String str = strutils::format(_T("vline%d: "), static_cast<int>(i));
+		std::vector<String> ary;
+		for (int j = 0; j < npanes; ++j)
+			ary.push_back(vlines[i][j] == DiffMap::GHOST_MAP_ENTRY ? _T("-----") : strutils::format(_T("%5d"), vlines[i][j]));
+		str += strutils::join(ary.begin(), ary.end(), _T(",")) + _T("\n");
+		OutputDebugString(str.c_str());
+	}
+}
+
+/**
+ * @brief Create map from virtual line to real line.
+ */
+static std::vector<std::array<int, 2>>
+CreateVirtualLineToRealLineMap(
+	const DiffMap& diffmap, int nlines0, int nlines1)
+{
+	std::vector<std::array<int, 2>> vlines;
+	int line0 = 0, line1 = 0;
+	while (line0 < nlines0)
+	{
+		const int map_line0 = diffmap.m_map[line0];
+		if (map_line0 == DiffMap::GHOST_MAP_ENTRY || map_line0 == DiffMap::BAD_MAP_ENTRY)
+		{
+			vlines.push_back({ line0++, DiffMap::GHOST_MAP_ENTRY });
+		}
+		else
+		{
+			while (line1 < map_line0)
+				vlines.push_back({ DiffMap::GHOST_MAP_ENTRY, line1++ });
+			vlines.push_back({ line0++, line1++ });
+		}
+	}
+	while (line1 < nlines1)
+		vlines.push_back({ DiffMap::GHOST_MAP_ENTRY, line1++ });
+	ValidateVirtualLineToRealLineMap(vlines, std::array<int, 2>{ nlines0, nlines1 });
+	return vlines;
+}
+
+/**
+ * @brief Create map from virtual line to real line. (3-way)
+ */
+static std::vector<std::array<int, 3>>
+CreateVirtualLineToRealLineMap3way(
+	const DiffMap& diffmap01, const DiffMap& diffmap12, const DiffMap& diffmap20,
+	int nlines0, int nlines1, int nlines2)
+{
+	std::vector<std::array<int, 2>> vlines01 = CreateVirtualLineToRealLineMap(diffmap01, nlines0, nlines1);
+	std::vector<std::array<int, 2>> vlines12 = CreateVirtualLineToRealLineMap(diffmap12, nlines1, nlines2);
+	std::vector<std::array<int, 2>> vlines20 = CreateVirtualLineToRealLineMap(diffmap20, nlines2, nlines0);
+	std::vector<std::array<int, 3>> vlines;
+	size_t i01 = 0, i12 = 0, i20 = 0;
+	int line0 = 0, line1 = 0, line2 = 0;
+	bool is_vlines20_usable = true;
+	// 1.
+	for (line1 = 0; line1 < nlines1; ++line1)
+	{
+		size_t i01b = i01;
+		size_t i12b = i12;
+		size_t i20b = i20;
+		// 1.1
+		for (; i01 < vlines01.size(); ++i01)
+			if (vlines01[i01][1] == line1)
+				break;
+		for (; i12 < vlines12.size(); ++i12)
+			if (vlines12[i12][0] == line1)
+				break;
+		assert(i01 < vlines01.size() && i12 < vlines12.size());
+		// 1.2 
+		bool used_vlines20 = false;
+		if (is_vlines20_usable)
+		{
+			if (vlines12[i12][1] != DiffMap::GHOST_MAP_ENTRY && vlines01[i01][0] != DiffMap::GHOST_MAP_ENTRY)
+			{
+				// 1.2.1
+				line2 = vlines12[i12][1];
+				line0 = vlines01[i01][0];
+				size_t i20tmp;
+				for (i20tmp = i20b; i20tmp < vlines20.size(); ++i20tmp)
+					if (vlines20[i20tmp][0] == line2 && vlines20[i20tmp][1] == line0)
+						break;
+				if (i20tmp < vlines20.size())
+				{
+					// 1.2.1.1
+					for (; i20 < i20tmp; ++i20)
+						vlines.push_back({ vlines20[i20][1], DiffMap::GHOST_MAP_ENTRY, vlines20[i20][0] });
+					++i20;
+					used_vlines20 = true;
+				}
+				else
+				{
+					// 1.2.1.2
+					is_vlines20_usable = false;
+				}
+			}
+			else
+			{
+				// 1.2.2
+				is_vlines20_usable = false;
+			}
+		}
+		// 1.3
+		if (!used_vlines20)
+		{
+			size_t i01tmp, i12tmp;
+			for (i01tmp = i01b, i12tmp = i12b; i01tmp < i01 && i12tmp < i12; ++i01tmp, ++i12tmp)
+				vlines.push_back({ vlines01[i01tmp][0], DiffMap::GHOST_MAP_ENTRY, vlines12[i12tmp][1] });
+			if (i01 - i01b < i12 - i12b)
+			{
+				// 1.3.1
+				for (; i12tmp < i12; ++i12tmp)
+					vlines.push_back({ DiffMap::GHOST_MAP_ENTRY, DiffMap::GHOST_MAP_ENTRY, vlines12[i12tmp][1] });
+			}
+			else if (i01 - i01b > i12 - i12b)
+			{
+				// 1.3.2
+				for (; i01tmp < i01; ++i01tmp)
+					vlines.push_back({ vlines01[i01tmp][0], DiffMap::GHOST_MAP_ENTRY, DiffMap::GHOST_MAP_ENTRY });
+			}
+		}
+		vlines.push_back({ vlines01[i01++][0], line1, vlines12[i12++][1]});
+	}
+	// 2. 
+	if (i01 < vlines01.size() || i12 < vlines12.size())
+	{
+		if (is_vlines20_usable)
+		{
+			// 2.1
+			for (; i20 < vlines20.size(); ++i20)
+				vlines.push_back({ vlines20[i20][1], DiffMap::GHOST_MAP_ENTRY, vlines20[i20][0] });
+		}
+		else
+		{
+			// 2.2
+			for (; i01 < vlines01.size() && i12 < vlines12.size(); ++i01, ++i12)
+				vlines.push_back({ vlines01[i01][0], DiffMap::GHOST_MAP_ENTRY, vlines12[i12][1] });
+			if (vlines01.size() - i01 < vlines12.size() - i12)
+			{
+				// 2.2.1
+				for (; i12 < vlines12.size(); ++i12)
+					vlines.push_back({ DiffMap::GHOST_MAP_ENTRY, DiffMap::GHOST_MAP_ENTRY, vlines12[i12][1] });
+			}
+			else if (vlines01.size() - i01 > vlines12.size() - i12)
+			{
+				// 2.2.2
+				for (; i01 < vlines01.size(); ++i01)
+					vlines.push_back({ vlines01[i01][0], DiffMap::GHOST_MAP_ENTRY, DiffMap::GHOST_MAP_ENTRY });
+			}
+		}
+	}
+	ValidateVirtualLineToRealLineMap(vlines, std::array<int, 3>{ nlines0, nlines1, nlines2 });
+#ifdef _DEBUG
+	PrintVirtualLineToRealLineMap(_T("vline01"), vlines01);
+	PrintVirtualLineToRealLineMap(_T("vline12"), vlines12);
+	PrintVirtualLineToRealLineMap(_T("vline20"), vlines20);
+	PrintVirtualLineToRealLineMap(_T("vline3way"), vlines);
+#endif
+	return vlines;
+}
+
+OP_TYPE CMergeDoc::ComputeOpType3way(
+	const std::vector<std::array<int, 3>>& vlines, size_t index,
+	const DIFFRANGE& diffrange, const DIFFOPTIONS& diffOptions)
+{
+	if (vlines[index][0] != DiffMap::GHOST_MAP_ENTRY &&
+	    vlines[index][1] == DiffMap::GHOST_MAP_ENTRY &&
+	    vlines[index][2] == DiffMap::GHOST_MAP_ENTRY)
+	{
+		return OP_1STONLY;
+	}
+	else if (vlines[index][0] == DiffMap::GHOST_MAP_ENTRY &&
+             vlines[index][1] != DiffMap::GHOST_MAP_ENTRY &&
+		     vlines[index][2] == DiffMap::GHOST_MAP_ENTRY)
+	{
+		return OP_2NDONLY;
+	}
+	else if (vlines[index][0] == DiffMap::GHOST_MAP_ENTRY &&
+	         vlines[index][1] == DiffMap::GHOST_MAP_ENTRY &&
+	         vlines[index][2] != DiffMap::GHOST_MAP_ENTRY)
+	{
+		return OP_3RDONLY;
+	}
+
+	int line0 = diffrange.begin[0] + vlines[index][0];
+	int line1 = diffrange.begin[1] + vlines[index][1];
+	int line2 = diffrange.begin[2] + vlines[index][2];
+
+	if (vlines[index][0] != DiffMap::GHOST_MAP_ENTRY &&
+	    vlines[index][1] != DiffMap::GHOST_MAP_ENTRY &&
+	    vlines[index][2] == DiffMap::GHOST_MAP_ENTRY)
+	{
+		String strLine0(m_ptBuf[0]->GetLineChars(line0), m_ptBuf[0]->GetFullLineLength(line0));
+		String strLine1(m_ptBuf[1]->GetLineChars(line1), m_ptBuf[1]->GetFullLineLength(line1));
+		if (strdiff::Compare(strLine0, strLine1,
+			!diffOptions.bIgnoreCase, !diffOptions.bIgnoreEol,
+			diffOptions.nIgnoreWhitespace, diffOptions.bIgnoreNumbers) == 0)
+			return OP_3RDONLY;
+		return OP_DIFF;
+	}
+	else if (vlines[index][0] != DiffMap::GHOST_MAP_ENTRY &&
+	         vlines[index][1] == DiffMap::GHOST_MAP_ENTRY &&
+	         vlines[index][2] != DiffMap::GHOST_MAP_ENTRY)
+	{
+		String strLine0(m_ptBuf[0]->GetLineChars(line0), m_ptBuf[0]->GetFullLineLength(line0));
+		String strLine2(m_ptBuf[2]->GetLineChars(line2), m_ptBuf[2]->GetFullLineLength(line2));
+		if (strdiff::Compare(strLine0, strLine2,
+			!diffOptions.bIgnoreCase, !diffOptions.bIgnoreEol,
+			diffOptions.nIgnoreWhitespace, diffOptions.bIgnoreNumbers) == 0)
+			return OP_2NDONLY;
+		return OP_DIFF;
+	}
+	else if (vlines[index][0] == DiffMap::GHOST_MAP_ENTRY &&
+	         vlines[index][1] != DiffMap::GHOST_MAP_ENTRY &&
+	         vlines[index][2] != DiffMap::GHOST_MAP_ENTRY)
+	{
+		String strLine1(m_ptBuf[1]->GetLineChars(line1), m_ptBuf[1]->GetFullLineLength(line1));
+		String strLine2(m_ptBuf[2]->GetLineChars(line2), m_ptBuf[2]->GetFullLineLength(line2));
+		if (strdiff::Compare(strLine1, strLine2,
+			!diffOptions.bIgnoreCase, !diffOptions.bIgnoreEol,
+			diffOptions.nIgnoreWhitespace, diffOptions.bIgnoreNumbers) == 0)
+			return OP_1STONLY;
+		return OP_DIFF;
+	}
+	else
+	{
+		String strLine0(m_ptBuf[0]->GetLineChars(line0), m_ptBuf[0]->GetFullLineLength(line0));
+		String strLine1(m_ptBuf[1]->GetLineChars(line1), m_ptBuf[1]->GetFullLineLength(line1));
+		String strLine2(m_ptBuf[2]->GetLineChars(line2), m_ptBuf[2]->GetFullLineLength(line2));
+		if (strdiff::Compare(strLine0, strLine1,
+			!diffOptions.bIgnoreCase, !diffOptions.bIgnoreEol,
+			diffOptions.nIgnoreWhitespace, diffOptions.bIgnoreNumbers) == 0)
+			return OP_3RDONLY;
+		if (strdiff::Compare(strLine0, strLine2,
+			!diffOptions.bIgnoreCase, !diffOptions.bIgnoreEol,
+			diffOptions.nIgnoreWhitespace, diffOptions.bIgnoreNumbers) == 0)
+			return OP_2NDONLY;
+		if (strdiff::Compare(strLine1, strLine2,
+			!diffOptions.bIgnoreCase, !diffOptions.bIgnoreEol,
+			diffOptions.nIgnoreWhitespace, diffOptions.bIgnoreNumbers) == 0)
+			return OP_1STONLY;
+		return OP_DIFF;
+	}
+}
+
 /**
  * @brief Divide diff blocks to match lines in diff blocks.
  */
@@ -45,72 +326,314 @@ void CMergeDoc::AdjustDiffBlocks()
 			const std::vector<WordDiff> worddiffs = GetWordDiffArrayInRange(diffrange.begin, diffrange.end);
 			DiffMap diffmap;
 			diffmap.InitDiffMap(nlines0);
-			AdjustDiffBlock(diffmap, diffrange, worddiffs, lo0, hi0, lo1, hi1);
+			AdjustDiffBlock(diffmap, diffrange, worddiffs, 0, 1, lo0, hi0, lo1, hi1);
+			ValidateDiffMap(diffmap);
+			std::vector<std::array<int, 2>> vlines = CreateVirtualLineToRealLineMap(diffmap, nlines0, nlines1);
 
 			// divide diff blocks
-			DIFFRANGE dr;
-			int line0, line1, lineend0;
-			for (line0 = 0, line1 = 0; line0 < nlines0;)
+			int line0 = 0, line1 = 0;
+			for (size_t i = 0; i < vlines.size();)
 			{
-				const int map_line0 = diffmap.m_map[line0];
-				if (map_line0 == DiffMap::GHOST_MAP_ENTRY ||
-						map_line0 == DiffMap::BAD_MAP_ENTRY)
+				DIFFRANGE dr;
+				size_t ib = i;
+				if ((vlines[i][0] != DiffMap::GHOST_MAP_ENTRY) &&
+					(vlines[i][1] != DiffMap::GHOST_MAP_ENTRY))
+				{
+					while (i < vlines.size() &&
+						(vlines[i][0] != DiffMap::GHOST_MAP_ENTRY) &&
+						(vlines[i][1] != DiffMap::GHOST_MAP_ENTRY))
+					{
+						line0++;
+						line1++;
+						i++;
+					}
+					dr.begin[0]  = diffrange.begin[0] + vlines[ib][0];
+					dr.begin[1]  = diffrange.begin[1] + vlines[ib][1];
+					dr.end[0]    = diffrange.begin[0] + vlines[i - 1][0];
+					dr.end[1]    = diffrange.begin[1] + vlines[i - 1][1];
+					dr.blank[0]  = dr.blank[1] = -1;
+					dr.op        = diffrange.op;
+					newDiffList.AddDiff(dr);
+				}
+				else if ((vlines[i][0] == DiffMap::GHOST_MAP_ENTRY) &&
+				         (vlines[i][1] != DiffMap::GHOST_MAP_ENTRY))
 				{
-					for (lineend0 = line0; lineend0 < nlines0; lineend0++)
+					while (i < vlines.size() &&
+					     (vlines[i][0] == DiffMap::GHOST_MAP_ENTRY) &&
+					     (vlines[i][1] != DiffMap::GHOST_MAP_ENTRY))
 					{
-						const int map_lineend0 = diffmap.m_map[lineend0];
-						if (map_lineend0 != DiffMap::GHOST_MAP_ENTRY &&
-								map_lineend0 != DiffMap::BAD_MAP_ENTRY)
-							break;
+						line1++;
+						i++;
 					}
 					dr.begin[0]  = diffrange.begin[0] + line0;
+					dr.begin[1]  = diffrange.begin[1] + vlines[ib][1];
+					dr.end[0]    = diffrange.begin[0] + line0 - 1;
+					dr.end[1]    = diffrange.begin[1] + vlines[i - 1][1];
+					dr.blank[0]  = dr.blank[1] = -1;
+					dr.op        = diffrange.op;
+					newDiffList.AddDiff(dr);
+				}
+				else if ((vlines[i][0] != DiffMap::GHOST_MAP_ENTRY) &&
+				         (vlines[i][1] == DiffMap::GHOST_MAP_ENTRY))
+				{
+					while (i < vlines.size() &&
+					     (vlines[i][0] != DiffMap::GHOST_MAP_ENTRY) &&
+					     (vlines[i][1] == DiffMap::GHOST_MAP_ENTRY))
+					{
+						line0++;
+						i++;
+					}
+					dr.begin[0]  = diffrange.begin[0] + vlines[ib][0];
 					dr.begin[1]  = diffrange.begin[1] + line1;
-					dr.end[0]    = diffrange.begin[0] + lineend0 - 1;
-					dr.end[1]    = dr.begin[1] - 1;
+					dr.end[0]    = diffrange.begin[0] + vlines[i - 1][0];
+					dr.end[1]    = diffrange.begin[1] + line1 - 1;
 					dr.blank[0]  = dr.blank[1] = -1;
-					dr.op        = OP_DIFF;
+					dr.op        = diffrange.op;
 					newDiffList.AddDiff(dr);
-					line0 = lineend0;
 				}
 				else
 				{
-					if (map_line0 > line1)
-					{
-						dr.begin[0]  = diffrange.begin[0] + line0;
-						dr.begin[1]  = diffrange.begin[1] + line1;
-						dr.end[0]    = dr.begin[0] - 1;
-						dr.end[1]    = diffrange.begin[1] + map_line0 - 1;
-						dr.blank[0]  = dr.blank[1] = -1;
-						dr.op        = OP_DIFF;
-						newDiffList.AddDiff(dr);
-						line1 = map_line0;
-					} 
+					assert(0);
+				}
+			}
+		}
+		else
+		{
+			newDiffList.AddDiff(diffrange);
+		}
+	}
 
-					for (lineend0 = line0 + 1; lineend0 < nlines0; lineend0++)
+	// recreate m_diffList
+	m_diffList.Clear();
+	nDiffCount = newDiffList.GetSize();
+	for (nDiff = 0; nDiff < nDiffCount; nDiff++)
+		m_diffList.AddDiff(*newDiffList.DiffRangeAt(nDiff));
+}
+
+/**
+ * @brief Divide diff blocks to match lines in diff blocks. (3-way)
+ */
+void CMergeDoc::AdjustDiffBlocks3way()
+{
+	int nDiff;
+	int nDiffCount = m_diffList.GetSize();
+
+	// Go through and do our best to line up lines within each diff block
+	// between left side and right side
+	DiffList newDiffList;
+	newDiffList.Clear();
+	for (nDiff = 0; nDiff < nDiffCount; nDiff++)
+	{
+		const DIFFRANGE & diffrange = *m_diffList.DiffRangeAt(nDiff);
+		// size map correctly (it will hold one entry for each left-side line
+		int nlines0 = diffrange.end[0] - diffrange.begin[0] + 1;
+		int nlines1 = diffrange.end[1] - diffrange.begin[1] + 1;
+		int nlines2 = diffrange.end[2] - diffrange.begin[2] + 1;
+		if ((nlines0 > 0) + (nlines1 > 0) + (nlines2 > 0) > 1)
+		{
+			// Call worker to do all lines in block
+			int lo0 = 0, hi0 = nlines0 - 1;
+			int lo1 = 0, hi1 = nlines1 - 1;
+			int lo2 = 0, hi2 = nlines2 - 1;
+			const std::vector<WordDiff> worddiffs01 = GetWordDiffArrayInRange(diffrange.begin, diffrange.end, 0, 1);
+			const std::vector<WordDiff> worddiffs12 = GetWordDiffArrayInRange(diffrange.begin, diffrange.end, 1, 2);
+			const std::vector<WordDiff> worddiffs20 = GetWordDiffArrayInRange(diffrange.begin, diffrange.end, 2, 0);
+			DiffMap diffmap01, diffmap12, diffmap20;
+			diffmap01.InitDiffMap(nlines0);
+			diffmap12.InitDiffMap(nlines1);
+			diffmap20.InitDiffMap(nlines2);
+			AdjustDiffBlock(diffmap01, diffrange, worddiffs01, 0, 1, lo0, hi0, lo1, hi1);
+			AdjustDiffBlock(diffmap12, diffrange, worddiffs12, 1, 2, lo1, hi1, lo2, hi2);
+			AdjustDiffBlock(diffmap20, diffrange, worddiffs20, 2, 0, lo2, hi2, lo0, hi0);
+			ValidateDiffMap(diffmap01);
+			ValidateDiffMap(diffmap12);
+			ValidateDiffMap(diffmap20);
+			std::vector<std::array<int, 3>> vlines = CreateVirtualLineToRealLineMap3way(diffmap01, diffmap12, diffmap20, nlines0, nlines1, nlines2);
+
+			DIFFOPTIONS diffOptions = {0};
+			m_diffWrapper.GetOptions(&diffOptions);
+			std::vector<OP_TYPE> opary(vlines.size());
+			for (size_t i = 0; i < vlines.size(); ++i)
+				opary[i] = (diffrange.op == OP_TRIVIAL) ?
+					OP_TRIVIAL :
+					ComputeOpType3way(vlines, i, diffrange, diffOptions);
+			// divide diff blocks
+			int line0 = 0, line1 = 0, line2 = 0;
+			for (size_t i = 0; i < vlines.size();)
+			{
+				DIFFRANGE dr;
+				size_t ib = i;
+				OP_TYPE op = opary[i];
+				if ((vlines[i][0] != DiffMap::GHOST_MAP_ENTRY) &&
+					(vlines[i][1] != DiffMap::GHOST_MAP_ENTRY) &&
+					(vlines[i][2] != DiffMap::GHOST_MAP_ENTRY))
+				{
+					while (i < vlines.size() &&
+						(vlines[i][0] != DiffMap::GHOST_MAP_ENTRY) &&
+						(vlines[i][1] != DiffMap::GHOST_MAP_ENTRY) &&
+						(vlines[i][2] != DiffMap::GHOST_MAP_ENTRY) &&
+						op == opary[i])
 					{
-						if (map_line0 != diffmap.m_map[lineend0 - 1] + 1)
-							break;
+						line0++;
+						line1++;
+						line2++;
+						i++;
+					}
+					dr.begin[0]  = diffrange.begin[0] + vlines[ib][0];
+					dr.begin[1]  = diffrange.begin[1] + vlines[ib][1];
+					dr.begin[2]  = diffrange.begin[2] + vlines[ib][2];
+					dr.end[0]    = diffrange.begin[0] + vlines[i - 1][0];
+					dr.end[1]    = diffrange.begin[1] + vlines[i - 1][1];
+					dr.end[2]    = diffrange.begin[2] + vlines[i - 1][2];
+					dr.blank[0]  = dr.blank[1] = dr.blank[2] = -1;
+					dr.op        = op;
+					newDiffList.AddDiff(dr);
+				}
+				else if ((vlines[i][0] == DiffMap::GHOST_MAP_ENTRY) &&
+				         (vlines[i][1] != DiffMap::GHOST_MAP_ENTRY) &&
+				         (vlines[i][2] != DiffMap::GHOST_MAP_ENTRY))
+				{
+					while (i < vlines.size() &&
+					     (vlines[i][0] == DiffMap::GHOST_MAP_ENTRY) &&
+					     (vlines[i][1] != DiffMap::GHOST_MAP_ENTRY) &&
+					     (vlines[i][2] != DiffMap::GHOST_MAP_ENTRY) &&
+						 op == opary[i])
+					{
+						line1++;
+						line2++;
+						i++;
 					}
 					dr.begin[0]  = diffrange.begin[0] + line0;
+					dr.begin[1]  = diffrange.begin[1] + vlines[ib][1];
+					dr.begin[2]  = diffrange.begin[2] + vlines[ib][2];
+					dr.end[0]    = diffrange.begin[0] + line0 - 1;
+					dr.end[1]    = diffrange.begin[1] + vlines[i - 1][1];
+					dr.end[2]    = diffrange.begin[2] + vlines[i - 1][2];
+					dr.blank[0]  = dr.blank[1] = dr.blank[2] = -1;
+					dr.op        = op;
+					newDiffList.AddDiff(dr);
+				}
+				else if ((vlines[i][0] != DiffMap::GHOST_MAP_ENTRY) &&
+				         (vlines[i][1] == DiffMap::GHOST_MAP_ENTRY) &&
+				         (vlines[i][2] != DiffMap::GHOST_MAP_ENTRY))
+				{
+					while (i < vlines.size() &&
+					     (vlines[i][0] != DiffMap::GHOST_MAP_ENTRY) &&
+					     (vlines[i][1] == DiffMap::GHOST_MAP_ENTRY) &&
+					     (vlines[i][2] != DiffMap::GHOST_MAP_ENTRY) &&
+						 op == opary[i])
+					{
+						line0++;
+						line2++;
+						i++;
+					}
+					dr.begin[0]  = diffrange.begin[0] + vlines[ib][0];
 					dr.begin[1]  = diffrange.begin[1] + line1;
-					dr.end[0]    = diffrange.begin[0] + lineend0 - 1;
-					dr.end[1]    = diffrange.begin[1] + diffmap.m_map[lineend0 - 1];
-					dr.blank[0]  = dr.blank[1] = -1;
-					dr.op        = diffrange.op == OP_TRIVIAL ? OP_TRIVIAL : OP_DIFF;
+					dr.begin[2]  = diffrange.begin[2] + vlines[ib][2];
+					dr.end[0]    = diffrange.begin[0] + vlines[i - 1][0];
+					dr.end[1]    = diffrange.begin[1] + line1 - 1;
+					dr.end[2]    = diffrange.begin[2] + vlines[i - 1][2];
+					dr.blank[0]  = dr.blank[1] = dr.blank[2] = -1;
+					dr.op        = op;
 					newDiffList.AddDiff(dr);
-					line0 = lineend0;
-					line1 = diffmap.m_map[lineend0 - 1] + 1;
 				}
-			}
-			if (line1 <= hi1)
-			{
-				dr.begin[0]  = diffrange.begin[0] + line0;
-				dr.begin[1]  = diffrange.begin[1] + line1;
-				dr.end[0]    = dr.begin[0] - 1;
-				dr.end[1]    = diffrange.begin[1] + hi1;
-				dr.blank[0]  = dr.blank[1] = -1;
-				dr.op        = diffrange.op == OP_TRIVIAL ? OP_TRIVIAL : OP_DIFF;
-				newDiffList.AddDiff(dr);
+				else if ((vlines[i][0] != DiffMap::GHOST_MAP_ENTRY) &&
+				         (vlines[i][1] != DiffMap::GHOST_MAP_ENTRY) &&
+				         (vlines[i][2] == DiffMap::GHOST_MAP_ENTRY))
+				{
+					while (i < vlines.size() &&
+					     (vlines[i][0] != DiffMap::GHOST_MAP_ENTRY) &&
+					     (vlines[i][1] != DiffMap::GHOST_MAP_ENTRY) &&
+					     (vlines[i][2] == DiffMap::GHOST_MAP_ENTRY) &&
+						 op == opary[i])
+					{
+						line0++;
+						line1++;
+						i++;
+					}
+					dr.begin[0]  = diffrange.begin[0] + vlines[ib][0];
+					dr.begin[1]  = diffrange.begin[1] + vlines[ib][1];
+					dr.begin[2]  = diffrange.begin[2] + line2;
+					dr.end[0]    = diffrange.begin[0] + vlines[i - 1][0];
+					dr.end[1]    = diffrange.begin[1] + vlines[i - 1][1];
+					dr.end[2]    = diffrange.begin[2] + line2 - 1;
+					dr.blank[0]  = dr.blank[1] = dr.blank[2] = -1;
+					dr.op        = op;
+					newDiffList.AddDiff(dr);
+				}
+				else if ((vlines[i][0] != DiffMap::GHOST_MAP_ENTRY) &&
+				         (vlines[i][1] == DiffMap::GHOST_MAP_ENTRY) &&
+				         (vlines[i][2] == DiffMap::GHOST_MAP_ENTRY))
+				{
+					while (i < vlines.size() &&
+					     (vlines[i][0] != DiffMap::GHOST_MAP_ENTRY) &&
+					     (vlines[i][1] == DiffMap::GHOST_MAP_ENTRY) &&
+				         (vlines[i][2] == DiffMap::GHOST_MAP_ENTRY) &&
+						 op == opary[i])
+					{
+						line0++;
+						i++;
+					}
+					dr.begin[0]  = diffrange.begin[0] + vlines[ib][0];
+					dr.begin[1]  = diffrange.begin[1] + line1;
+					dr.begin[2]  = diffrange.begin[2] + line2;
+					dr.end[0]    = diffrange.begin[0] + vlines[i - 1][0];
+					dr.end[1]    = diffrange.begin[1] + line1 - 1;
+					dr.end[2]    = diffrange.begin[2] + line2 - 1;
+					dr.blank[0]  = dr.blank[1] = dr.blank[2] = -1;
+					dr.op        = op;
+					newDiffList.AddDiff(dr);
+				}
+				else if ((vlines[i][0] == DiffMap::GHOST_MAP_ENTRY) &&
+				         (vlines[i][1] != DiffMap::GHOST_MAP_ENTRY) &&
+				         (vlines[i][2] == DiffMap::GHOST_MAP_ENTRY))
+				{
+					while (i < vlines.size() &&
+					     (vlines[i][0] == DiffMap::GHOST_MAP_ENTRY) &&
+					     (vlines[i][1] != DiffMap::GHOST_MAP_ENTRY) &&
+					     (vlines[i][2] == DiffMap::GHOST_MAP_ENTRY) &&
+						 op == opary[i])
+					{
+						line1++;
+						i++;
+					}
+					dr.begin[0]  = diffrange.begin[0] + line0;
+					dr.begin[1]  = diffrange.begin[1] + vlines[ib][1];
+					dr.begin[2]  = diffrange.begin[2] + line2;
+					dr.end[0]    = diffrange.begin[0] + line0 - 1;
+					dr.end[1]    = diffrange.begin[1] + vlines[i - 1][1];
+					dr.end[2]    = diffrange.begin[2] + line2 - 1;
+					dr.blank[0]  = dr.blank[1] = dr.blank[2] = -1;
+					dr.op        = op;
+					newDiffList.AddDiff(dr);
+				}
+				else if ((vlines[i][0] == DiffMap::GHOST_MAP_ENTRY) &&
+				         (vlines[i][1] == DiffMap::GHOST_MAP_ENTRY) &&
+				         (vlines[i][2] != DiffMap::GHOST_MAP_ENTRY))
+				{
+					while (i < vlines.size() &&
+					     (vlines[i][0] == DiffMap::GHOST_MAP_ENTRY) &&
+					     (vlines[i][1] == DiffMap::GHOST_MAP_ENTRY) &&
+					     (vlines[i][2] != DiffMap::GHOST_MAP_ENTRY) &&
+						 op == opary[i])
+					{
+						line2++;
+						i++;
+					}
+					dr.begin[0]  = diffrange.begin[0] + line0;
+					dr.begin[1]  = diffrange.begin[1] + line1;
+					dr.begin[2]  = diffrange.begin[2] + vlines[ib][2];
+					dr.end[0]    = diffrange.begin[0] + line0 - 1;
+					dr.end[1]    = diffrange.begin[1] + line1 - 1;
+					dr.end[2]    = diffrange.begin[2] + vlines[i - 1][2];
+					dr.blank[0]  = dr.blank[1] = dr.blank[2] = -1;
+					dr.op        = op;
+					newDiffList.AddDiff(dr);
+				}
+				else
+				{
+					assert(0);
+				}
 			}
 		}
 		else
@@ -132,19 +655,30 @@ void CMergeDoc::AdjustDiffBlocks()
  * The cost of making them equal is the measure of their dissimilarity
  * which is their Levenshtein distance.
  */
-int CMergeDoc::GetMatchCost(int line0, int line1, const std::vector<WordDiff>& worddiffs)
+int CMergeDoc::GetMatchCost(const DIFFRANGE& dr, int i0, int i1, int line0, int line1, const std::vector<WordDiff>& worddiffs)
 {
 	int matchlen = 0;
 	for (size_t i = 0; i < worddiffs.size(); ++i)
 	{
 		if (i == 0)
 		{
-			if (line0 == worddiffs[i].beginline[0] && line1 == worddiffs[i].beginline[1])
-				matchlen += worddiffs[i].begin[0];
+			if (line0 < worddiffs[0].beginline[0] && line1 < worddiffs[0].beginline[1])
+			{
+				if (line0 - dr.begin[i0] == line1 - dr.begin[i1])
+					matchlen += m_ptBuf[i0]->GetFullLineLength(line0);
+			}
+			else if (line0 == worddiffs[0].beginline[0] && line1 == worddiffs[0].beginline[1])
+				matchlen += worddiffs[0].begin[0];
 		}
 		else
 		{
-			if (worddiffs[i - 1].endline[0] <= line0 && worddiffs[i - 1].endline[1] <= line1 &&
+			if (worddiffs[i - 1].endline[0] < line0 && worddiffs[i - 1].endline[1] < line1 &&
+			    line0 < worddiffs[i].beginline[0] && line1 < worddiffs[i].beginline[1])
+			{
+				if (line0 - worddiffs[i - 1].endline[0] == line1 - worddiffs[i - 1].endline[1])
+					matchlen += m_ptBuf[i0]->GetFullLineLength(line0);
+			}
+			else if (worddiffs[i - 1].endline[0] <= line0 && worddiffs[i - 1].endline[1] <= line1 &&
 			    line0 <= worddiffs[i].beginline[0] && line1 <= worddiffs[i].beginline[1])
 			{
 				if (worddiffs[i - 1].endline[0] == worddiffs[i].beginline[0])
@@ -157,9 +691,29 @@ int CMergeDoc::GetMatchCost(int line0, int line1, const std::vector<WordDiff>& w
 			worddiffs[i + 1].beginline[0] != worddiffs[i].endline[0] && worddiffs[i + 1].beginline[1] != worddiffs[i].endline[1])
 		{
 			if (worddiffs[i].endline[0] == line0 && worddiffs[i].endline[1] == line1)
-				matchlen += m_ptBuf[0]->GetFullLineLength(line0) - worddiffs[i].end[0] - 1;
+				matchlen += m_ptBuf[i0]->GetFullLineLength(line0) - worddiffs[i].end[0] - 1;
+		}
+	}
+	if (worddiffs.empty())
+	{
+		if (line0 - dr.begin[i0] == line1 - dr.begin[i1])
+			matchlen += m_ptBuf[i0]->GetFullLineLength(line0);
+	}
+	else
+	{
+		auto lastWordDiff = worddiffs.back();
+		if (lastWordDiff.endline[0] < line0 && lastWordDiff.endline[1] < line1)
+		{
+			if (line0 - lastWordDiff.endline[0] == line1 - lastWordDiff.endline[1])
+				matchlen += m_ptBuf[i0]->GetFullLineLength(line0);
 		}
 	}
+/*
+#ifdef _DEBUG
+	String str = strutils::format(_T("pane%d,%d line%5d,%5d match len: %d\n"), i0, i1, line0, line1, matchlen);
+	OutputDebugString(str.c_str());
+#endif
+*/
 	return -matchlen;
 }
 
@@ -172,21 +726,28 @@ int CMergeDoc::GetMatchCost(int line0, int line1, const std::vector<WordDiff>& w
  * Find best match, and use that to split problem into two parts (above & below match)
  * and call ourselves recursively to solve each smaller problem
  */
-void CMergeDoc::AdjustDiffBlock(DiffMap & diffMap, const DIFFRANGE & diffrange, const std::vector<WordDiff>& worddiffs, int lo0, int hi0, int lo1, int hi1)
+void CMergeDoc::AdjustDiffBlock(DiffMap & diffMap, const DIFFRANGE & diffrange, const std::vector<WordDiff>& worddiffs, int i0, int i1, int lo0, int hi0, int lo1, int hi1)
 {
 	// Map & lo & hi numbers are all relative to this block
 	// We need to know offsets to find actual line strings from buffer
-	int offset0 = diffrange.begin[0];
-	int offset1 = diffrange.begin[1];
+	int offset0 = diffrange.begin[i0];
+	int offset1 = diffrange.begin[i1];
 
 	// # of lines on left and right
 	int lines0 = hi0 - lo0 + 1;
 	int lines1 = hi1 - lo1 + 1;
 
-
-	ASSERT(lines0 > 0 && lines1 > 0);
-
 	// shortcut special case
+	if (lines0 == 0)
+	{
+		return;
+	}
+	if (lines1 == 0)
+	{
+		for (int w=0; w<lines0; ++w)
+			diffMap.m_map[w] = DiffMap::GHOST_MAP_ENTRY;
+		return;
+	}
 	if (lines0 == 1 && lines1 == 1)
 	{
 		diffMap.m_map[lo0] = hi1;
@@ -206,7 +767,7 @@ void CMergeDoc::AdjustDiffBlock(DiffMap & diffMap, const DIFFRANGE & diffrange,
 		}
 		return false;
 	};
-	if (tooManyCharacters(0, offset0 + lo0, offset0 + hi0) || tooManyCharacters(1, offset1 + lo1, offset1 + hi1))
+	if (tooManyCharacters(i0, offset0 + lo0, offset0 + hi0) || tooManyCharacters(i1, offset1 + lo1, offset1 + hi1))
 	{
 		// Do simple 1:1 mapping
 		// but try to stay within original block
@@ -242,7 +803,7 @@ void CMergeDoc::AdjustDiffBlock(DiffMap & diffMap, const DIFFRANGE & diffrange,
 	{
 		for (int j=lo1; j<=hi1; ++j)
 		{
-			int savings = GetMatchCost(offset0 + i, offset1 + j, worddiffs);
+			int savings = GetMatchCost(diffrange, i0, i1, offset0 + i, offset1 + j, worddiffs);
 			// TODO
 			// Need to penalize assignments that push us outside the box
 			// further than is required
@@ -268,7 +829,7 @@ void CMergeDoc::AdjustDiffBlock(DiffMap & diffMap, const DIFFRANGE & diffrange,
 	{
 		if (lo1 < itarget)
 		{
-			AdjustDiffBlock(diffMap, diffrange, worddiffs, lo0, ibest-1, lo1, itarget-1);
+			AdjustDiffBlock(diffMap, diffrange, worddiffs, i0, i1, lo0, ibest-1, lo1, itarget-1);
 		}
 		else
 		{
@@ -285,7 +846,7 @@ void CMergeDoc::AdjustDiffBlock(DiffMap & diffMap, const DIFFRANGE & diffrange,
 	{
 		if (itarget < hi1)
 		{
-			AdjustDiffBlock(diffMap, diffrange, worddiffs, ibest + 1, hi0,
+			AdjustDiffBlock(diffMap, diffrange, worddiffs, i0, i1, ibest + 1, hi0,
 					itarget + 1, hi1);
 		}
 		else
diff --git a/Src/MergeDocLineDiffs.cpp b/Src/MergeDocLineDiffs.cpp
index 9e25e62d081..912b1e150e6 100644
--- a/Src/MergeDocLineDiffs.cpp
+++ b/Src/MergeDocLineDiffs.cpp
@@ -331,27 +331,36 @@ std::vector<WordDiff> CMergeDoc::GetWordDiffArrayInDiffBlock(int nDiff)
 	return worddiffs;
 }
 
-std::vector<WordDiff> CMergeDoc::GetWordDiffArrayInRange(const int begin[3], const int end[3])
+std::vector<WordDiff>
+CMergeDoc::GetWordDiffArrayInRange(const int begin[3], const int end[3], int pane1/*=-1*/, int pane2/*=-1*/)
 {
 	DIFFOPTIONS diffOptions = {0};
 	m_diffWrapper.GetOptions(&diffOptions);
 	String str[3];
 	std::unique_ptr<int[]> nOffsets[3];
 	std::vector<WordDiff> worddiffs;
-	for (int file = 0; file < m_nBuffers; file++)
+	std::vector<int> panes;
+	if (pane1 == -1 && pane2 == -1)
+		panes = (m_nBuffers == 2) ? std::vector<int>{0, 1} : std::vector<int>{ 0, 1, 2 };
+	else
+		panes = std::vector<int>{ pane1, pane2 };
+	for (size_t i = 0; i < panes.size(); ++i)
 	{
+		int file = panes[i];
 		int nLineBegin = begin[file];
 		int nLineEnd = end[file];
 		if (nLineEnd >= m_ptBuf[file]->GetLineCount())
 			return worddiffs;
 		nOffsets[file].reset(new int[nLineEnd - nLineBegin + 1]);
 		CString strText;
-		if (nLineBegin != nLineEnd || m_ptBuf[file]->GetLineLength(nLineEnd) > 0)
-			m_ptBuf[file]->GetTextWithoutEmptys(nLineBegin, 0, nLineEnd, m_ptBuf[file]->GetLineLength(nLineEnd), strText);
-		strText += m_ptBuf[file]->GetLineEol(nLineEnd);
-		str[file].assign(strText, strText.GetLength());
-
-		nOffsets[file][0] = 0;
+		if (nLineBegin <= nLineEnd)
+		{
+			if (nLineBegin != nLineEnd || m_ptBuf[file]->GetLineLength(nLineEnd) > 0)
+				m_ptBuf[file]->GetTextWithoutEmptys(nLineBegin, 0, nLineEnd, m_ptBuf[file]->GetLineLength(nLineEnd), strText);
+			strText += m_ptBuf[file]->GetLineEol(nLineEnd);
+			nOffsets[file][0] = 0;
+		}
+		str[i].assign(strText, strText.GetLength());
 		for (int nLine = nLineBegin; nLine < nLineEnd; nLine++)
 			nOffsets[file][nLine-nLineBegin+1] = nOffsets[file][nLine-nLineBegin] + m_ptBuf[file]->GetFullLineLength(nLine);
 	}
@@ -364,55 +373,56 @@ std::vector<WordDiff> CMergeDoc::GetWordDiffArrayInRange(const int begin[3], con
 	bool byteColoring = GetByteColoringOption();
 
 	// Make the call to stringdiffs, which does all the hard & tedious computations
-	std::vector<strdiff::wdiff> wdiffs = strdiff::ComputeWordDiffs(m_nBuffers, str, casitive, eolSensitive, xwhite, diffOptions.bIgnoreNumbers ,breakType, byteColoring);
+	std::vector<strdiff::wdiff> wdiffs =
+		strdiff::ComputeWordDiffs(static_cast<int>(panes.size()), str, casitive, eolSensitive, xwhite, diffOptions.bIgnoreNumbers, breakType, byteColoring);
 
-	int i;
 	std::vector<strdiff::wdiff>::iterator it;
-	for (i = 0, it = wdiffs.begin(); it != wdiffs.end(); ++i, ++it)
+	for (it = wdiffs.begin(); it != wdiffs.end(); ++it)
 	{
 		WordDiff wd;
-		for (int file = 0; file < m_nBuffers; file++)
+		for (size_t i = 0; i < panes.size(); ++i)
 		{
+			int file = panes[i];
 			int nLineBegin = begin[file];
 			int nLineEnd = end[file];
 			int nLine;
 			for (nLine = nLineBegin; nLine < nLineEnd; nLine++)
 			{
-				if (it->begin[file] == nOffsets[file][nLine-nLineBegin] || it->begin[file] < nOffsets[file][nLine-nLineBegin+1])
+				if (it->begin[i] == nOffsets[file][nLine-nLineBegin] || it->begin[i] < nOffsets[file][nLine-nLineBegin+1])
 					break;
 			}
-			wd.beginline[file] = nLine;
-			wd.begin[file] = it->begin[file] - nOffsets[file][nLine-nLineBegin];
-			if (m_ptBuf[file]->GetLineLength(nLine) < wd.begin[file])
+			wd.beginline[i] = nLine;
+			wd.begin[i] = it->begin[i] - nOffsets[file][nLine-nLineBegin];
+			if (m_ptBuf[file]->GetLineLength(nLine) < wd.begin[i])
 			{
-				if (wd.beginline[file] < m_ptBuf[file]->GetLineCount() - 1)
+				if (wd.beginline[i] < m_ptBuf[file]->GetLineCount() - 1)
 				{
-					wd.begin[file] = 0;
-					wd.beginline[file]++;
+					wd.begin[i] = 0;
+					wd.beginline[i]++;
 				}
 				else
 				{
-					wd.begin[file] = m_ptBuf[file]->GetLineLength(nLine);
+					wd.begin[i] = m_ptBuf[file]->GetLineLength(nLine);
 				}
 			}
 
 			for (; nLine < nLineEnd; nLine++)
 			{
-				if (it->end[file] + 1 == nOffsets[file][nLine-nLineBegin] || it->end[file] + 1 < nOffsets[file][nLine-nLineBegin+1])
+				if (it->end[i] + 1 == nOffsets[file][nLine-nLineBegin] || it->end[i] + 1 < nOffsets[file][nLine-nLineBegin+1])
 					break;
 			}
-			wd.endline[file] = nLine;
-			wd.end[file] = it->end[file]  + 1 - nOffsets[file][nLine-nLineBegin];
-			if (m_ptBuf[file]->GetLineLength(nLine) < wd.end[file])
+			wd.endline[i] = nLine;
+			wd.end[i] = it->end[i]  + 1 - nOffsets[file][nLine-nLineBegin];
+			if (m_ptBuf[file]->GetLineLength(nLine) < wd.end[i])
 			{
-				if (wd.endline[file] < m_ptBuf[file]->GetLineCount() - 1)
+				if (wd.endline[i] < m_ptBuf[file]->GetLineCount() - 1)
 				{
-					wd.end[file] = 0;
-					wd.endline[file]++;
+					wd.end[i] = 0;
+					wd.endline[i]++;
 				}
 				else
 				{
-					wd.end[file] = m_ptBuf[file]->GetLineLength(nLine);
+					wd.end[i] = m_ptBuf[file]->GetLineLength(nLine);
 				}
 			}
 		}
diff --git a/Src/stringdiffs.cpp b/Src/stringdiffs.cpp
index 745dc350731..e54cd4d1a9f 100644
--- a/Src/stringdiffs.cpp
+++ b/Src/stringdiffs.cpp
@@ -195,6 +195,40 @@ ComputeWordDiffs(int nFiles, const String *str,
 	return diffs;
 }
 
+int Compare(const String& str1, const String& str2,
+	bool case_sensitive, bool eol_sensitive, int whitespace, bool ignore_numbers)
+{
+	if (case_sensitive && eol_sensitive && whitespace == WHITESPACE_COMPARE_ALL && !ignore_numbers)
+		return str2.compare(str1);
+	String s1 = str1, s2 = str2;
+	if (!case_sensitive)
+	{
+		s1 = strutils::makelower(s1);
+		s2 = strutils::makelower(s2);
+	}
+	if (whitespace == WHITESPACE_IGNORE_CHANGE)
+	{
+		strutils::replace_chars(s1, _T(" \t"), _T(" "));
+		strutils::replace_chars(s2, _T(" \t"), _T(" "));
+	}
+	else if (whitespace == WHITESPACE_IGNORE_ALL)
+	{
+		strutils::replace_chars(s1, _T(" \t"), _T(""));
+		strutils::replace_chars(s2, _T(" \t"), _T(""));
+	}
+	if (!eol_sensitive)
+	{
+		strutils::replace_chars(s1, _T("\r\n"), _T("\n"));
+		strutils::replace_chars(s2, _T("\r\n"), _T("\n"));
+	}
+	if (ignore_numbers)
+	{
+		strutils::replace_chars(s1, _T("0123456789"), _T(""));
+		strutils::replace_chars(s2, _T("0123456789"), _T(""));
+	}
+	return s2.compare(s1);
+}
+
 /**
  * @brief stringdiffs constructor simply loads all members from arguments
  */
diff --git a/Src/stringdiffs.h b/Src/stringdiffs.h
index 5882045a19a..6c32ca82c04 100644
--- a/Src/stringdiffs.h
+++ b/Src/stringdiffs.h
@@ -45,5 +45,7 @@ std::vector<wdiff> ComputeWordDiffs(const String& str1, const String& str2,
 	bool case_sensitive, bool eol_sensitive, int whitespace, bool ignore_numbers, int breakType, bool byte_level);
 std::vector<wdiff> ComputeWordDiffs(int nStrings, const String *str, 
                    bool case_sensitive, bool eol_sensitive, int whitespace, bool ignore_numbers, int breakType, bool byte_level);
+int Compare(const String& str1, const String& str2,
+	bool case_sensitive, bool eol_sensitive, int whitespace, bool ignore_numbers);
 
 }
diff --git a/Testing/Data/Compare/Dir1/file3way1_!!!.txt b/Testing/Data/Compare/Dir1/file3way1_!!!.txt
new file mode 100644
index 00000000000..e0696a4766b
--- /dev/null
+++ b/Testing/Data/Compare/Dir1/file3way1_!!!.txt
@@ -0,0 +1,3 @@
+01234
+A
+56789
diff --git a/Testing/Data/Compare/Dir1/file3way1_!!G.txt b/Testing/Data/Compare/Dir1/file3way1_!!G.txt
new file mode 100644
index 00000000000..e0696a4766b
--- /dev/null
+++ b/Testing/Data/Compare/Dir1/file3way1_!!G.txt
@@ -0,0 +1,3 @@
+01234
+A
+56789
diff --git a/Testing/Data/Compare/Dir1/file3way1_!==.txt b/Testing/Data/Compare/Dir1/file3way1_!==.txt
new file mode 100644
index 00000000000..e0696a4766b
--- /dev/null
+++ b/Testing/Data/Compare/Dir1/file3way1_!==.txt
@@ -0,0 +1,3 @@
+01234
+A
+56789
diff --git a/Testing/Data/Compare/Dir1/file3way1_!G!.txt b/Testing/Data/Compare/Dir1/file3way1_!G!.txt
new file mode 100644
index 00000000000..e0696a4766b
--- /dev/null
+++ b/Testing/Data/Compare/Dir1/file3way1_!G!.txt
@@ -0,0 +1,3 @@
+01234
+A
+56789
diff --git a/Testing/Data/Compare/Dir1/file3way1_!GG.txt b/Testing/Data/Compare/Dir1/file3way1_!GG.txt
new file mode 100644
index 00000000000..e0696a4766b
--- /dev/null
+++ b/Testing/Data/Compare/Dir1/file3way1_!GG.txt
@@ -0,0 +1,3 @@
+01234
+A
+56789
diff --git a/Testing/Data/Compare/Dir1/file3way1_=!=.txt b/Testing/Data/Compare/Dir1/file3way1_=!=.txt
new file mode 100644
index 00000000000..f7ee25ffaca
--- /dev/null
+++ b/Testing/Data/Compare/Dir1/file3way1_=!=.txt
@@ -0,0 +1,3 @@
+01234
+AC
+56789
diff --git a/Testing/Data/Compare/Dir1/file3way1_==!.txt b/Testing/Data/Compare/Dir1/file3way1_==!.txt
new file mode 100644
index 00000000000..b5df55af10d
--- /dev/null
+++ b/Testing/Data/Compare/Dir1/file3way1_==!.txt
@@ -0,0 +1,3 @@
+01234
+AB
+56789
diff --git a/Testing/Data/Compare/Dir1/file3way1_==G.txt b/Testing/Data/Compare/Dir1/file3way1_==G.txt
new file mode 100644
index 00000000000..b5df55af10d
--- /dev/null
+++ b/Testing/Data/Compare/Dir1/file3way1_==G.txt
@@ -0,0 +1,3 @@
+01234
+AB
+56789
diff --git a/Testing/Data/Compare/Dir1/file3way1_=G=.txt b/Testing/Data/Compare/Dir1/file3way1_=G=.txt
new file mode 100644
index 00000000000..f7ee25ffaca
--- /dev/null
+++ b/Testing/Data/Compare/Dir1/file3way1_=G=.txt
@@ -0,0 +1,3 @@
+01234
+AC
+56789
diff --git a/Testing/Data/Compare/Dir1/file3way1_G!!.txt b/Testing/Data/Compare/Dir1/file3way1_G!!.txt
new file mode 100644
index 00000000000..eb3debb2bc4
--- /dev/null
+++ b/Testing/Data/Compare/Dir1/file3way1_G!!.txt
@@ -0,0 +1,2 @@
+01234
+56789
diff --git a/Testing/Data/Compare/Dir1/file3way1_G!G.txt b/Testing/Data/Compare/Dir1/file3way1_G!G.txt
new file mode 100644
index 00000000000..eb3debb2bc4
--- /dev/null
+++ b/Testing/Data/Compare/Dir1/file3way1_G!G.txt
@@ -0,0 +1,2 @@
+01234
+56789
diff --git a/Testing/Data/Compare/Dir1/file3way1_G==.txt b/Testing/Data/Compare/Dir1/file3way1_G==.txt
new file mode 100644
index 00000000000..eb3debb2bc4
--- /dev/null
+++ b/Testing/Data/Compare/Dir1/file3way1_G==.txt
@@ -0,0 +1,2 @@
+01234
+56789
diff --git a/Testing/Data/Compare/Dir1/file3way1_GG!.txt b/Testing/Data/Compare/Dir1/file3way1_GG!.txt
new file mode 100644
index 00000000000..eb3debb2bc4
--- /dev/null
+++ b/Testing/Data/Compare/Dir1/file3way1_GG!.txt
@@ -0,0 +1,2 @@
+01234
+56789
diff --git a/Testing/Data/Compare/Dir1/file3way2_!!!.txt b/Testing/Data/Compare/Dir1/file3way2_!!!.txt
new file mode 100644
index 00000000000..1a044a708d4
--- /dev/null
+++ b/Testing/Data/Compare/Dir1/file3way2_!!!.txt
@@ -0,0 +1,4 @@
+01234
+abcde
+A
+56789
diff --git a/Testing/Data/Compare/Dir1/file3way2_!!G.txt b/Testing/Data/Compare/Dir1/file3way2_!!G.txt
new file mode 100644
index 00000000000..f5cd9f8bbee
--- /dev/null
+++ b/Testing/Data/Compare/Dir1/file3way2_!!G.txt
@@ -0,0 +1,4 @@
+01234
+abced
+A
+56789
diff --git a/Testing/Data/Compare/Dir1/file3way2_!==.txt b/Testing/Data/Compare/Dir1/file3way2_!==.txt
new file mode 100644
index 00000000000..f5cd9f8bbee
--- /dev/null
+++ b/Testing/Data/Compare/Dir1/file3way2_!==.txt
@@ -0,0 +1,4 @@
+01234
+abced
+A
+56789
diff --git a/Testing/Data/Compare/Dir1/file3way2_!G!.txt b/Testing/Data/Compare/Dir1/file3way2_!G!.txt
new file mode 100644
index 00000000000..f5cd9f8bbee
--- /dev/null
+++ b/Testing/Data/Compare/Dir1/file3way2_!G!.txt
@@ -0,0 +1,4 @@
+01234
+abced
+A
+56789
diff --git a/Testing/Data/Compare/Dir1/file3way2_!GG.txt b/Testing/Data/Compare/Dir1/file3way2_!GG.txt
new file mode 100644
index 00000000000..f5cd9f8bbee
--- /dev/null
+++ b/Testing/Data/Compare/Dir1/file3way2_!GG.txt
@@ -0,0 +1,4 @@
+01234
+abced
+A
+56789
diff --git a/Testing/Data/Compare/Dir1/file3way2_=!=.txt b/Testing/Data/Compare/Dir1/file3way2_=!=.txt
new file mode 100644
index 00000000000..d147f4f298a
--- /dev/null
+++ b/Testing/Data/Compare/Dir1/file3way2_=!=.txt
@@ -0,0 +1,4 @@
+01234
+abced
+AC
+56789
diff --git a/Testing/Data/Compare/Dir1/file3way2_==!.txt b/Testing/Data/Compare/Dir1/file3way2_==!.txt
new file mode 100644
index 00000000000..ed0d18e348f
--- /dev/null
+++ b/Testing/Data/Compare/Dir1/file3way2_==!.txt
@@ -0,0 +1,4 @@
+01234
+abced
+AB
+56789
diff --git a/Testing/Data/Compare/Dir1/file3way2_==G.txt b/Testing/Data/Compare/Dir1/file3way2_==G.txt
new file mode 100644
index 00000000000..ed0d18e348f
--- /dev/null
+++ b/Testing/Data/Compare/Dir1/file3way2_==G.txt
@@ -0,0 +1,4 @@
+01234
+abced
+AB
+56789
diff --git a/Testing/Data/Compare/Dir1/file3way2_=G=.txt b/Testing/Data/Compare/Dir1/file3way2_=G=.txt
new file mode 100644
index 00000000000..d147f4f298a
--- /dev/null
+++ b/Testing/Data/Compare/Dir1/file3way2_=G=.txt
@@ -0,0 +1,4 @@
+01234
+abced
+AC
+56789
diff --git a/Testing/Data/Compare/Dir1/file3way2_G!!.txt b/Testing/Data/Compare/Dir1/file3way2_G!!.txt
new file mode 100644
index 00000000000..26adf930acb
--- /dev/null
+++ b/Testing/Data/Compare/Dir1/file3way2_G!!.txt
@@ -0,0 +1,3 @@
+01234
+abced
+56789
diff --git a/Testing/Data/Compare/Dir1/file3way2_G!G.txt b/Testing/Data/Compare/Dir1/file3way2_G!G.txt
new file mode 100644
index 00000000000..26adf930acb
--- /dev/null
+++ b/Testing/Data/Compare/Dir1/file3way2_G!G.txt
@@ -0,0 +1,3 @@
+01234
+abced
+56789
diff --git a/Testing/Data/Compare/Dir1/file3way2_G==.txt b/Testing/Data/Compare/Dir1/file3way2_G==.txt
new file mode 100644
index 00000000000..26adf930acb
--- /dev/null
+++ b/Testing/Data/Compare/Dir1/file3way2_G==.txt
@@ -0,0 +1,3 @@
+01234
+abced
+56789
diff --git a/Testing/Data/Compare/Dir1/file3way2_GG!.txt b/Testing/Data/Compare/Dir1/file3way2_GG!.txt
new file mode 100644
index 00000000000..26adf930acb
--- /dev/null
+++ b/Testing/Data/Compare/Dir1/file3way2_GG!.txt
@@ -0,0 +1,3 @@
+01234
+abced
+56789
diff --git a/Testing/Data/Compare/Dir1/file3way3_1.2.1-2.1.txt b/Testing/Data/Compare/Dir1/file3way3_1.2.1-2.1.txt
new file mode 100644
index 00000000000..46f740df91d
--- /dev/null
+++ b/Testing/Data/Compare/Dir1/file3way3_1.2.1-2.1.txt
@@ -0,0 +1,4 @@
+01234
+A 1111
+A 2222
+56789
diff --git a/Testing/Data/Compare/Dir1/file3way3_1.2.1.1.txt b/Testing/Data/Compare/Dir1/file3way3_1.2.1.1.txt
new file mode 100644
index 00000000000..46f740df91d
--- /dev/null
+++ b/Testing/Data/Compare/Dir1/file3way3_1.2.1.1.txt
@@ -0,0 +1,4 @@
+01234
+A 1111
+A 2222
+56789
diff --git a/Testing/Data/Compare/Dir1/file3way3_1.2.2-1.3.1.txt b/Testing/Data/Compare/Dir1/file3way3_1.2.2-1.3.1.txt
new file mode 100644
index 00000000000..33fa7254d1a
--- /dev/null
+++ b/Testing/Data/Compare/Dir1/file3way3_1.2.2-1.3.1.txt
@@ -0,0 +1,6 @@
+01234
+A 1111
+A 2222
+A 3333
+A 5555
+56789
diff --git a/Testing/Data/Compare/Dir1/file3way3_1.2.2-1.3.2.txt b/Testing/Data/Compare/Dir1/file3way3_1.2.2-1.3.2.txt
new file mode 100644
index 00000000000..a60bc7acc92
--- /dev/null
+++ b/Testing/Data/Compare/Dir1/file3way3_1.2.2-1.3.2.txt
@@ -0,0 +1,7 @@
+01234
+A 1111
+A 2222
+A 3333
+A 4444
+A 5555
+56789
diff --git a/Testing/Data/Compare/Dir1/file3way3_1.2.2-2.2.1.txt b/Testing/Data/Compare/Dir1/file3way3_1.2.2-2.2.1.txt
new file mode 100644
index 00000000000..716fd5682c4
--- /dev/null
+++ b/Testing/Data/Compare/Dir1/file3way3_1.2.2-2.2.1.txt
@@ -0,0 +1,5 @@
+01234
+A 1111
+A 2222
+A 3333
+56789
diff --git a/Testing/Data/Compare/Dir1/file3way3_1.2.2-2.2.2.txt b/Testing/Data/Compare/Dir1/file3way3_1.2.2-2.2.2.txt
new file mode 100644
index 00000000000..a69daed3ff6
--- /dev/null
+++ b/Testing/Data/Compare/Dir1/file3way3_1.2.2-2.2.2.txt
@@ -0,0 +1,6 @@
+01234
+A 1111
+A 2222
+A 3333
+A 4444
+56789
diff --git a/Testing/Data/Compare/Dir2/file3way1_!!!.txt b/Testing/Data/Compare/Dir2/file3way1_!!!.txt
new file mode 100644
index 00000000000..98b9867df32
--- /dev/null
+++ b/Testing/Data/Compare/Dir2/file3way1_!!!.txt
@@ -0,0 +1,3 @@
+01234
+B
+56789
diff --git a/Testing/Data/Compare/Dir2/file3way1_!!G.txt b/Testing/Data/Compare/Dir2/file3way1_!!G.txt
new file mode 100644
index 00000000000..98b9867df32
--- /dev/null
+++ b/Testing/Data/Compare/Dir2/file3way1_!!G.txt
@@ -0,0 +1,3 @@
+01234
+B
+56789
diff --git a/Testing/Data/Compare/Dir2/file3way1_!==.txt b/Testing/Data/Compare/Dir2/file3way1_!==.txt
new file mode 100644
index 00000000000..d066941aa51
--- /dev/null
+++ b/Testing/Data/Compare/Dir2/file3way1_!==.txt
@@ -0,0 +1,3 @@
+01234
+BC
+56789
diff --git a/Testing/Data/Compare/Dir2/file3way1_!G!.txt b/Testing/Data/Compare/Dir2/file3way1_!G!.txt
new file mode 100644
index 00000000000..eb3debb2bc4
--- /dev/null
+++ b/Testing/Data/Compare/Dir2/file3way1_!G!.txt
@@ -0,0 +1,2 @@
+01234
+56789
diff --git a/Testing/Data/Compare/Dir2/file3way1_!GG.txt b/Testing/Data/Compare/Dir2/file3way1_!GG.txt
new file mode 100644
index 00000000000..eb3debb2bc4
--- /dev/null
+++ b/Testing/Data/Compare/Dir2/file3way1_!GG.txt
@@ -0,0 +1,2 @@
+01234
+56789
diff --git a/Testing/Data/Compare/Dir2/file3way1_=!=.txt b/Testing/Data/Compare/Dir2/file3way1_=!=.txt
new file mode 100644
index 00000000000..98b9867df32
--- /dev/null
+++ b/Testing/Data/Compare/Dir2/file3way1_=!=.txt
@@ -0,0 +1,3 @@
+01234
+B
+56789
diff --git a/Testing/Data/Compare/Dir2/file3way1_==!.txt b/Testing/Data/Compare/Dir2/file3way1_==!.txt
new file mode 100644
index 00000000000..b5df55af10d
--- /dev/null
+++ b/Testing/Data/Compare/Dir2/file3way1_==!.txt
@@ -0,0 +1,3 @@
+01234
+AB
+56789
diff --git a/Testing/Data/Compare/Dir2/file3way1_==G.txt b/Testing/Data/Compare/Dir2/file3way1_==G.txt
new file mode 100644
index 00000000000..b5df55af10d
--- /dev/null
+++ b/Testing/Data/Compare/Dir2/file3way1_==G.txt
@@ -0,0 +1,3 @@
+01234
+AB
+56789
diff --git a/Testing/Data/Compare/Dir2/file3way1_=G=.txt b/Testing/Data/Compare/Dir2/file3way1_=G=.txt
new file mode 100644
index 00000000000..eb3debb2bc4
--- /dev/null
+++ b/Testing/Data/Compare/Dir2/file3way1_=G=.txt
@@ -0,0 +1,2 @@
+01234
+56789
diff --git a/Testing/Data/Compare/Dir2/file3way1_G!!.txt b/Testing/Data/Compare/Dir2/file3way1_G!!.txt
new file mode 100644
index 00000000000..98b9867df32
--- /dev/null
+++ b/Testing/Data/Compare/Dir2/file3way1_G!!.txt
@@ -0,0 +1,3 @@
+01234
+B
+56789
diff --git a/Testing/Data/Compare/Dir2/file3way1_G!G.txt b/Testing/Data/Compare/Dir2/file3way1_G!G.txt
new file mode 100644
index 00000000000..98b9867df32
--- /dev/null
+++ b/Testing/Data/Compare/Dir2/file3way1_G!G.txt
@@ -0,0 +1,3 @@
+01234
+B
+56789
diff --git a/Testing/Data/Compare/Dir2/file3way1_G==.txt b/Testing/Data/Compare/Dir2/file3way1_G==.txt
new file mode 100644
index 00000000000..d066941aa51
--- /dev/null
+++ b/Testing/Data/Compare/Dir2/file3way1_G==.txt
@@ -0,0 +1,3 @@
+01234
+BC
+56789
diff --git a/Testing/Data/Compare/Dir2/file3way1_GG!.txt b/Testing/Data/Compare/Dir2/file3way1_GG!.txt
new file mode 100644
index 00000000000..eb3debb2bc4
--- /dev/null
+++ b/Testing/Data/Compare/Dir2/file3way1_GG!.txt
@@ -0,0 +1,2 @@
+01234
+56789
diff --git a/Testing/Data/Compare/Dir2/file3way2_!!!.txt b/Testing/Data/Compare/Dir2/file3way2_!!!.txt
new file mode 100644
index 00000000000..a35d115266b
--- /dev/null
+++ b/Testing/Data/Compare/Dir2/file3way2_!!!.txt
@@ -0,0 +1,4 @@
+01234
+efghi
+B
+56789
diff --git a/Testing/Data/Compare/Dir2/file3way2_!!G.txt b/Testing/Data/Compare/Dir2/file3way2_!!G.txt
new file mode 100644
index 00000000000..a35d115266b
--- /dev/null
+++ b/Testing/Data/Compare/Dir2/file3way2_!!G.txt
@@ -0,0 +1,4 @@
+01234
+efghi
+B
+56789
diff --git a/Testing/Data/Compare/Dir2/file3way2_!==.txt b/Testing/Data/Compare/Dir2/file3way2_!==.txt
new file mode 100644
index 00000000000..70f8b7a1a14
--- /dev/null
+++ b/Testing/Data/Compare/Dir2/file3way2_!==.txt
@@ -0,0 +1,4 @@
+01234
+efghi
+BC
+56789
diff --git a/Testing/Data/Compare/Dir2/file3way2_!G!.txt b/Testing/Data/Compare/Dir2/file3way2_!G!.txt
new file mode 100644
index 00000000000..5048ffc4d3d
--- /dev/null
+++ b/Testing/Data/Compare/Dir2/file3way2_!G!.txt
@@ -0,0 +1,3 @@
+01234
+efghi
+56789
diff --git a/Testing/Data/Compare/Dir2/file3way2_!GG.txt b/Testing/Data/Compare/Dir2/file3way2_!GG.txt
new file mode 100644
index 00000000000..5048ffc4d3d
--- /dev/null
+++ b/Testing/Data/Compare/Dir2/file3way2_!GG.txt
@@ -0,0 +1,3 @@
+01234
+efghi
+56789
diff --git a/Testing/Data/Compare/Dir2/file3way2_=!=.txt b/Testing/Data/Compare/Dir2/file3way2_=!=.txt
new file mode 100644
index 00000000000..a35d115266b
--- /dev/null
+++ b/Testing/Data/Compare/Dir2/file3way2_=!=.txt
@@ -0,0 +1,4 @@
+01234
+efghi
+B
+56789
diff --git a/Testing/Data/Compare/Dir2/file3way2_==!.txt b/Testing/Data/Compare/Dir2/file3way2_==!.txt
new file mode 100644
index 00000000000..1ec49eb0a04
--- /dev/null
+++ b/Testing/Data/Compare/Dir2/file3way2_==!.txt
@@ -0,0 +1,4 @@
+01234
+efghi
+AB
+56789
diff --git a/Testing/Data/Compare/Dir2/file3way2_==G.txt b/Testing/Data/Compare/Dir2/file3way2_==G.txt
new file mode 100644
index 00000000000..1ec49eb0a04
--- /dev/null
+++ b/Testing/Data/Compare/Dir2/file3way2_==G.txt
@@ -0,0 +1,4 @@
+01234
+efghi
+AB
+56789
diff --git a/Testing/Data/Compare/Dir2/file3way2_=G=.txt b/Testing/Data/Compare/Dir2/file3way2_=G=.txt
new file mode 100644
index 00000000000..5048ffc4d3d
--- /dev/null
+++ b/Testing/Data/Compare/Dir2/file3way2_=G=.txt
@@ -0,0 +1,3 @@
+01234
+efghi
+56789
diff --git a/Testing/Data/Compare/Dir2/file3way2_G!!.txt b/Testing/Data/Compare/Dir2/file3way2_G!!.txt
new file mode 100644
index 00000000000..a35d115266b
--- /dev/null
+++ b/Testing/Data/Compare/Dir2/file3way2_G!!.txt
@@ -0,0 +1,4 @@
+01234
+efghi
+B
+56789
diff --git a/Testing/Data/Compare/Dir2/file3way2_G!G.txt b/Testing/Data/Compare/Dir2/file3way2_G!G.txt
new file mode 100644
index 00000000000..a35d115266b
--- /dev/null
+++ b/Testing/Data/Compare/Dir2/file3way2_G!G.txt
@@ -0,0 +1,4 @@
+01234
+efghi
+B
+56789
diff --git a/Testing/Data/Compare/Dir2/file3way2_G==.txt b/Testing/Data/Compare/Dir2/file3way2_G==.txt
new file mode 100644
index 00000000000..70f8b7a1a14
--- /dev/null
+++ b/Testing/Data/Compare/Dir2/file3way2_G==.txt
@@ -0,0 +1,4 @@
+01234
+efghi
+BC
+56789
diff --git a/Testing/Data/Compare/Dir2/file3way2_GG!.txt b/Testing/Data/Compare/Dir2/file3way2_GG!.txt
new file mode 100644
index 00000000000..5048ffc4d3d
--- /dev/null
+++ b/Testing/Data/Compare/Dir2/file3way2_GG!.txt
@@ -0,0 +1,3 @@
+01234
+efghi
+56789
diff --git a/Testing/Data/Compare/Dir2/file3way3_1.2.1-2.1.txt b/Testing/Data/Compare/Dir2/file3way3_1.2.1-2.1.txt
new file mode 100644
index 00000000000..add9cb25447
--- /dev/null
+++ b/Testing/Data/Compare/Dir2/file3way3_1.2.1-2.1.txt
@@ -0,0 +1,3 @@
+01234
+B 1111
+56789
diff --git a/Testing/Data/Compare/Dir2/file3way3_1.2.1.1.txt b/Testing/Data/Compare/Dir2/file3way3_1.2.1.1.txt
new file mode 100644
index 00000000000..962490634c1
--- /dev/null
+++ b/Testing/Data/Compare/Dir2/file3way3_1.2.1.1.txt
@@ -0,0 +1,3 @@
+01234
+B 2222
+56789
diff --git a/Testing/Data/Compare/Dir2/file3way3_1.2.2-1.3.1.txt b/Testing/Data/Compare/Dir2/file3way3_1.2.2-1.3.1.txt
new file mode 100644
index 00000000000..29170313ef7
--- /dev/null
+++ b/Testing/Data/Compare/Dir2/file3way3_1.2.2-1.3.1.txt
@@ -0,0 +1,6 @@
+01234
+B 1111
+B 2222
+B 3333
+B 5555
+56789
diff --git a/Testing/Data/Compare/Dir2/file3way3_1.2.2-1.3.2.txt b/Testing/Data/Compare/Dir2/file3way3_1.2.2-1.3.2.txt
new file mode 100644
index 00000000000..29170313ef7
--- /dev/null
+++ b/Testing/Data/Compare/Dir2/file3way3_1.2.2-1.3.2.txt
@@ -0,0 +1,6 @@
+01234
+B 1111
+B 2222
+B 3333
+B 5555
+56789
diff --git a/Testing/Data/Compare/Dir2/file3way3_1.2.2-2.2.1.txt b/Testing/Data/Compare/Dir2/file3way3_1.2.2-2.2.1.txt
new file mode 100644
index 00000000000..5f3c0dc44bb
--- /dev/null
+++ b/Testing/Data/Compare/Dir2/file3way3_1.2.2-2.2.1.txt
@@ -0,0 +1,5 @@
+01234
+B 1111
+B 2222
+B 3333
+56789
diff --git a/Testing/Data/Compare/Dir2/file3way3_1.2.2-2.2.2.txt b/Testing/Data/Compare/Dir2/file3way3_1.2.2-2.2.2.txt
new file mode 100644
index 00000000000..5f3c0dc44bb
--- /dev/null
+++ b/Testing/Data/Compare/Dir2/file3way3_1.2.2-2.2.2.txt
@@ -0,0 +1,5 @@
+01234
+B 1111
+B 2222
+B 3333
+56789
diff --git a/Testing/Data/Compare/Dir3/file3way1_!!!.txt b/Testing/Data/Compare/Dir3/file3way1_!!!.txt
new file mode 100644
index 00000000000..0f1b581a674
--- /dev/null
+++ b/Testing/Data/Compare/Dir3/file3way1_!!!.txt
@@ -0,0 +1,3 @@
+01234
+C
+56789
diff --git a/Testing/Data/Compare/Dir3/file3way1_!!G.txt b/Testing/Data/Compare/Dir3/file3way1_!!G.txt
new file mode 100644
index 00000000000..eb3debb2bc4
--- /dev/null
+++ b/Testing/Data/Compare/Dir3/file3way1_!!G.txt
@@ -0,0 +1,2 @@
+01234
+56789
diff --git a/Testing/Data/Compare/Dir3/file3way1_!==.txt b/Testing/Data/Compare/Dir3/file3way1_!==.txt
new file mode 100644
index 00000000000..d066941aa51
--- /dev/null
+++ b/Testing/Data/Compare/Dir3/file3way1_!==.txt
@@ -0,0 +1,3 @@
+01234
+BC
+56789
diff --git a/Testing/Data/Compare/Dir3/file3way1_!G!.txt b/Testing/Data/Compare/Dir3/file3way1_!G!.txt
new file mode 100644
index 00000000000..0f1b581a674
--- /dev/null
+++ b/Testing/Data/Compare/Dir3/file3way1_!G!.txt
@@ -0,0 +1,3 @@
+01234
+C
+56789
diff --git a/Testing/Data/Compare/Dir3/file3way1_!GG.txt b/Testing/Data/Compare/Dir3/file3way1_!GG.txt
new file mode 100644
index 00000000000..eb3debb2bc4
--- /dev/null
+++ b/Testing/Data/Compare/Dir3/file3way1_!GG.txt
@@ -0,0 +1,2 @@
+01234
+56789
diff --git a/Testing/Data/Compare/Dir3/file3way1_=!=.txt b/Testing/Data/Compare/Dir3/file3way1_=!=.txt
new file mode 100644
index 00000000000..f7ee25ffaca
--- /dev/null
+++ b/Testing/Data/Compare/Dir3/file3way1_=!=.txt
@@ -0,0 +1,3 @@
+01234
+AC
+56789
diff --git a/Testing/Data/Compare/Dir3/file3way1_==!.txt b/Testing/Data/Compare/Dir3/file3way1_==!.txt
new file mode 100644
index 00000000000..0f1b581a674
--- /dev/null
+++ b/Testing/Data/Compare/Dir3/file3way1_==!.txt
@@ -0,0 +1,3 @@
+01234
+C
+56789
diff --git a/Testing/Data/Compare/Dir3/file3way1_==G.txt b/Testing/Data/Compare/Dir3/file3way1_==G.txt
new file mode 100644
index 00000000000..eb3debb2bc4
--- /dev/null
+++ b/Testing/Data/Compare/Dir3/file3way1_==G.txt
@@ -0,0 +1,2 @@
+01234
+56789
diff --git a/Testing/Data/Compare/Dir3/file3way1_=G=.txt b/Testing/Data/Compare/Dir3/file3way1_=G=.txt
new file mode 100644
index 00000000000..f7ee25ffaca
--- /dev/null
+++ b/Testing/Data/Compare/Dir3/file3way1_=G=.txt
@@ -0,0 +1,3 @@
+01234
+AC
+56789
diff --git a/Testing/Data/Compare/Dir3/file3way1_G!!.txt b/Testing/Data/Compare/Dir3/file3way1_G!!.txt
new file mode 100644
index 00000000000..0f1b581a674
--- /dev/null
+++ b/Testing/Data/Compare/Dir3/file3way1_G!!.txt
@@ -0,0 +1,3 @@
+01234
+C
+56789
diff --git a/Testing/Data/Compare/Dir3/file3way1_G!G.txt b/Testing/Data/Compare/Dir3/file3way1_G!G.txt
new file mode 100644
index 00000000000..eb3debb2bc4
--- /dev/null
+++ b/Testing/Data/Compare/Dir3/file3way1_G!G.txt
@@ -0,0 +1,2 @@
+01234
+56789
diff --git a/Testing/Data/Compare/Dir3/file3way1_G==.txt b/Testing/Data/Compare/Dir3/file3way1_G==.txt
new file mode 100644
index 00000000000..d066941aa51
--- /dev/null
+++ b/Testing/Data/Compare/Dir3/file3way1_G==.txt
@@ -0,0 +1,3 @@
+01234
+BC
+56789
diff --git a/Testing/Data/Compare/Dir3/file3way1_GG!.txt b/Testing/Data/Compare/Dir3/file3way1_GG!.txt
new file mode 100644
index 00000000000..0f1b581a674
--- /dev/null
+++ b/Testing/Data/Compare/Dir3/file3way1_GG!.txt
@@ -0,0 +1,3 @@
+01234
+C
+56789
diff --git a/Testing/Data/Compare/Dir3/file3way2_!!!.txt b/Testing/Data/Compare/Dir3/file3way2_!!!.txt
new file mode 100644
index 00000000000..96890c86a9c
--- /dev/null
+++ b/Testing/Data/Compare/Dir3/file3way2_!!!.txt
@@ -0,0 +1,4 @@
+01234
+jklmn
+C
+56789
diff --git a/Testing/Data/Compare/Dir3/file3way2_!!G.txt b/Testing/Data/Compare/Dir3/file3way2_!!G.txt
new file mode 100644
index 00000000000..c78576e1b7e
--- /dev/null
+++ b/Testing/Data/Compare/Dir3/file3way2_!!G.txt
@@ -0,0 +1,3 @@
+01234
+jklmn
+56789
diff --git a/Testing/Data/Compare/Dir3/file3way2_!==.txt b/Testing/Data/Compare/Dir3/file3way2_!==.txt
new file mode 100644
index 00000000000..4a8d60f0296
--- /dev/null
+++ b/Testing/Data/Compare/Dir3/file3way2_!==.txt
@@ -0,0 +1,4 @@
+01234
+jklmn
+BC
+56789
diff --git a/Testing/Data/Compare/Dir3/file3way2_!G!.txt b/Testing/Data/Compare/Dir3/file3way2_!G!.txt
new file mode 100644
index 00000000000..96890c86a9c
--- /dev/null
+++ b/Testing/Data/Compare/Dir3/file3way2_!G!.txt
@@ -0,0 +1,4 @@
+01234
+jklmn
+C
+56789
diff --git a/Testing/Data/Compare/Dir3/file3way2_!GG.txt b/Testing/Data/Compare/Dir3/file3way2_!GG.txt
new file mode 100644
index 00000000000..c78576e1b7e
--- /dev/null
+++ b/Testing/Data/Compare/Dir3/file3way2_!GG.txt
@@ -0,0 +1,3 @@
+01234
+jklmn
+56789
diff --git a/Testing/Data/Compare/Dir3/file3way2_=!=.txt b/Testing/Data/Compare/Dir3/file3way2_=!=.txt
new file mode 100644
index 00000000000..1f01362cb6c
--- /dev/null
+++ b/Testing/Data/Compare/Dir3/file3way2_=!=.txt
@@ -0,0 +1,4 @@
+01234
+jklmn
+AC
+56789
diff --git a/Testing/Data/Compare/Dir3/file3way2_==!.txt b/Testing/Data/Compare/Dir3/file3way2_==!.txt
new file mode 100644
index 00000000000..96890c86a9c
--- /dev/null
+++ b/Testing/Data/Compare/Dir3/file3way2_==!.txt
@@ -0,0 +1,4 @@
+01234
+jklmn
+C
+56789
diff --git a/Testing/Data/Compare/Dir3/file3way2_==G.txt b/Testing/Data/Compare/Dir3/file3way2_==G.txt
new file mode 100644
index 00000000000..c78576e1b7e
--- /dev/null
+++ b/Testing/Data/Compare/Dir3/file3way2_==G.txt
@@ -0,0 +1,3 @@
+01234
+jklmn
+56789
diff --git a/Testing/Data/Compare/Dir3/file3way2_=G=.txt b/Testing/Data/Compare/Dir3/file3way2_=G=.txt
new file mode 100644
index 00000000000..1f01362cb6c
--- /dev/null
+++ b/Testing/Data/Compare/Dir3/file3way2_=G=.txt
@@ -0,0 +1,4 @@
+01234
+jklmn
+AC
+56789
diff --git a/Testing/Data/Compare/Dir3/file3way2_G!!.txt b/Testing/Data/Compare/Dir3/file3way2_G!!.txt
new file mode 100644
index 00000000000..96890c86a9c
--- /dev/null
+++ b/Testing/Data/Compare/Dir3/file3way2_G!!.txt
@@ -0,0 +1,4 @@
+01234
+jklmn
+C
+56789
diff --git a/Testing/Data/Compare/Dir3/file3way2_G!G.txt b/Testing/Data/Compare/Dir3/file3way2_G!G.txt
new file mode 100644
index 00000000000..c78576e1b7e
--- /dev/null
+++ b/Testing/Data/Compare/Dir3/file3way2_G!G.txt
@@ -0,0 +1,3 @@
+01234
+jklmn
+56789
diff --git a/Testing/Data/Compare/Dir3/file3way2_G==.txt b/Testing/Data/Compare/Dir3/file3way2_G==.txt
new file mode 100644
index 00000000000..4a8d60f0296
--- /dev/null
+++ b/Testing/Data/Compare/Dir3/file3way2_G==.txt
@@ -0,0 +1,4 @@
+01234
+jklmn
+BC
+56789
diff --git a/Testing/Data/Compare/Dir3/file3way2_GG!.txt b/Testing/Data/Compare/Dir3/file3way2_GG!.txt
new file mode 100644
index 00000000000..96890c86a9c
--- /dev/null
+++ b/Testing/Data/Compare/Dir3/file3way2_GG!.txt
@@ -0,0 +1,4 @@
+01234
+jklmn
+C
+56789
diff --git a/Testing/Data/Compare/Dir3/file3way3_1.2.1-2.1.txt b/Testing/Data/Compare/Dir3/file3way3_1.2.1-2.1.txt
new file mode 100644
index 00000000000..d806d57f5a4
--- /dev/null
+++ b/Testing/Data/Compare/Dir3/file3way3_1.2.1-2.1.txt
@@ -0,0 +1,5 @@
+01234
+C 1111
+C 2222
+C 3333
+56789
diff --git a/Testing/Data/Compare/Dir3/file3way3_1.2.1.1.txt b/Testing/Data/Compare/Dir3/file3way3_1.2.1.1.txt
new file mode 100644
index 00000000000..1da2435b815
--- /dev/null
+++ b/Testing/Data/Compare/Dir3/file3way3_1.2.1.1.txt
@@ -0,0 +1,4 @@
+01234
+C 1111
+C 2222
+56789
diff --git a/Testing/Data/Compare/Dir3/file3way3_1.2.2-1.3.1.txt b/Testing/Data/Compare/Dir3/file3way3_1.2.2-1.3.1.txt
new file mode 100644
index 00000000000..ac933d6ee57
--- /dev/null
+++ b/Testing/Data/Compare/Dir3/file3way3_1.2.2-1.3.1.txt
@@ -0,0 +1,6 @@
+01234
+C 2222
+C 3333
+C 4444
+C 5555
+56789
diff --git a/Testing/Data/Compare/Dir3/file3way3_1.2.2-1.3.2.txt b/Testing/Data/Compare/Dir3/file3way3_1.2.2-1.3.2.txt
new file mode 100644
index 00000000000..0e9af1c2a75
--- /dev/null
+++ b/Testing/Data/Compare/Dir3/file3way3_1.2.2-1.3.2.txt
@@ -0,0 +1,5 @@
+01234
+C 2222
+C 3333
+C 5555
+56789
diff --git a/Testing/Data/Compare/Dir3/file3way3_1.2.2-2.2.1.txt b/Testing/Data/Compare/Dir3/file3way3_1.2.2-2.2.1.txt
new file mode 100644
index 00000000000..75fdd6829a2
--- /dev/null
+++ b/Testing/Data/Compare/Dir3/file3way3_1.2.2-2.2.1.txt
@@ -0,0 +1,5 @@
+01234
+C 2222
+C 3333
+C 4444
+56789
diff --git a/Testing/Data/Compare/Dir3/file3way3_1.2.2-2.2.2.txt b/Testing/Data/Compare/Dir3/file3way3_1.2.2-2.2.2.txt
new file mode 100644
index 00000000000..b6ca0c9fef5
--- /dev/null
+++ b/Testing/Data/Compare/Dir3/file3way3_1.2.2-2.2.2.txt
@@ -0,0 +1,4 @@
+01234
+C 2222
+C 3333
+56789
diff --git a/Testing/GoogleTest/StringDiffs/stringdiffs_test.cpp b/Testing/GoogleTest/StringDiffs/stringdiffs_test.cpp
index b301932c30e..69ad20d6f3b 100644
--- a/Testing/GoogleTest/StringDiffs/stringdiffs_test.cpp
+++ b/Testing/GoogleTest/StringDiffs/stringdiffs_test.cpp
@@ -723,4 +723,113 @@ namespace
 
 	}
 
+	TEST_F(StringDiffsTest, CompareCase)
+	{
+		int result;
+		result = strdiff::Compare(_T("abc"), _T("abc"), false, true, 0, false);
+		EXPECT_EQ(0, result);
+		result = strdiff::Compare(_T("ABC"), _T("abc"), false, true, 0, false);
+		EXPECT_EQ(0, result);
+		result = strdiff::Compare(_T("abc"), _T("ABC"), false, true, 0, false);
+		EXPECT_EQ(0, result);
+		result = strdiff::Compare(_T("aBC"), _T("Bcd"), false, true, 0, false);
+		EXPECT_EQ(1, result);
+		result = strdiff::Compare(_T("Bcd"), _T("aBC"), false, true, 0, false);
+		EXPECT_EQ(-1, result);
+	}
+
+	TEST_F(StringDiffsTest, CompareWhiltespaces1)
+	{
+		int result;
+		result = strdiff::Compare(_T("abc def"), _T("abc def"), true, true, 1, false);
+		EXPECT_EQ(0, result);
+		result = strdiff::Compare(_T("abc  def"), _T("abc def"), true, true, 1, false);
+		EXPECT_EQ(0, result);
+		result = strdiff::Compare(_T("abc def"), _T("abc  def"), true, true, 1, false);
+		EXPECT_EQ(0, result);
+		result = strdiff::Compare(_T("abc \tdef"), _T("abc def"), true, true, 1, false);
+		EXPECT_EQ(0, result);
+		result = strdiff::Compare(_T("abc def"), _T("abc \tdef"), true, true, 1, false);
+		EXPECT_EQ(0, result);
+		result = strdiff::Compare(_T("abc def"), _T("abcdef"), true, true, 1, false);
+		EXPECT_EQ(1, result);
+		result = strdiff::Compare(_T("abcdef"), _T("abc def"), true, true, 1, false);
+		EXPECT_EQ(-1, result);
+	}
+
+	TEST_F(StringDiffsTest, CompareWhiltespaces2)
+	{
+		int result;
+		result = strdiff::Compare(_T("abc def"), _T("abc def"), true, true, 2, false);
+		EXPECT_EQ(0, result);
+		result = strdiff::Compare(_T("abc  def"), _T("abc def"), true, true, 2, false);
+		EXPECT_EQ(0, result);
+		result = strdiff::Compare(_T("abc def"), _T("abc  def"), true, true, 2, false);
+		EXPECT_EQ(0, result);
+		result = strdiff::Compare(_T("abc \tdef"), _T("abc def"), true, true, 2, false);
+		EXPECT_EQ(0, result);
+		result = strdiff::Compare(_T("abc def"), _T("abc \tdef"), true, true, 2, false);
+		EXPECT_EQ(0, result);
+		result = strdiff::Compare(_T("abc def"), _T("abcdef"), true, true, 2, false);
+		EXPECT_EQ(0, result);
+		result = strdiff::Compare(_T("abcdef"), _T("abc def"), true, true, 2, false);
+		EXPECT_EQ(0, result);
+		result = strdiff::Compare(_T("abc\tdef"), _T("abcdef"), true, true, 2, false);
+		EXPECT_EQ(0, result);
+		result = strdiff::Compare(_T("abcdef"), _T("abc\tdef"), true, true, 2, false);
+		EXPECT_EQ(0, result);
+		result = strdiff::Compare(_T("abcde"), _T("abcdef"), true, true, 2, false);
+		EXPECT_EQ(1, result);
+		result = strdiff::Compare(_T("abcdef"), _T("abcde"), true, true, 2, false);
+		EXPECT_EQ(-1, result);
+	}
+
+	TEST_F(StringDiffsTest, CompareEOL)
+	{
+		int result;
+		result = strdiff::Compare(_T("abc\r\n"), _T("abc\r\n"), true, false, 0, false);
+		EXPECT_EQ(0, result);
+		result = strdiff::Compare(_T("abc\r\n"), _T("abc\r"), true, false, 0, false);
+		EXPECT_EQ(0, result);
+		result = strdiff::Compare(_T("abc\r"), _T("abc\r\n"), true, false, 0, false);
+		EXPECT_EQ(0, result);
+		result = strdiff::Compare(_T("abc\r\n"), _T("abc\n"), true, false, 0, false);
+		EXPECT_EQ(0, result);
+		result = strdiff::Compare(_T("abc\n"), _T("abc\r\n"), true, false, 0, false);
+		EXPECT_EQ(0, result);
+		result = strdiff::Compare(_T("abc\n"), _T("abc\r"), true, false, 0, false);
+		EXPECT_EQ(0, result);
+		result = strdiff::Compare(_T("abc\r"), _T("abc\n"), true, false, 0, false);
+		EXPECT_EQ(0, result);
+		result = strdiff::Compare(String(_T("abc\r\0"), 5), _T("abc\r\n"), true, false, 0, false);
+		EXPECT_EQ(-1, result);
+		result = strdiff::Compare(_T("abc\r\n"), String(_T("abc\r\0"), 5), true, false, 0, false);
+		EXPECT_EQ(1, result);
+	}
+
+	TEST_F(StringDiffsTest, CompareNumbers)
+	{
+		int result;
+		result = strdiff::Compare(_T("1a"), _T("2a"), true, true, 0, true);
+		EXPECT_EQ(0, result);
+		result = strdiff::Compare(_T("a123"), _T("a234"), true, true, 0, true);
+		EXPECT_EQ(0, result);
+		result = strdiff::Compare(_T("a"), _T("123a"), true, true, 0, true);
+		EXPECT_EQ(0, result);
+		result = strdiff::Compare(_T("123a"), _T("a"), true, true, 0, true);
+		EXPECT_EQ(0, result);
+		result = strdiff::Compare(_T("123"), _T(""), true, true, 0, true);
+		EXPECT_EQ(0, result);
+		result = strdiff::Compare(_T(""), _T("123"), true, true, 0, true);
+		EXPECT_EQ(0, result);
+		result = strdiff::Compare(_T("123a"), _T("123b"), true, true, 0, true);
+		EXPECT_EQ(1, result);
+		result = strdiff::Compare(_T("123b"), _T("123a"), true, true, 0, true);
+		EXPECT_EQ(-1, result);
+		result = strdiff::Compare(_T("a123"), _T("b123"), true, true, 0, true);
+		EXPECT_EQ(1, result);
+		result = strdiff::Compare(_T("b123"), _T("a123"), true, true, 0, true);
+		EXPECT_EQ(-1, result);
+	}
+
 }  // namespace