Make the 'Match similar lines' option work for 3-way comparisons

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.

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);

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;
 	}
 }

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

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;