More performance optimization for the Remove Empty Lines command

Close #12544

PowerEditor/src/Notepad_plus.cpp

@@ -1493,11 +1493,11 @@ void Notepad_plus::removeEmptyLine(bool isBlankContained)
 	FindOption env;
 	if (isBlankContained)
 	{
-		env._str2Search = TEXT("^([\\t ]*$(\\r?\\n|\\r))(\\1)*");
+		env._str2Search = TEXT("^(?>[\\t ]*[\\r\\n]+)+");
 	}
 	else
 	{
-		env._str2Search = TEXT("^$(\\r?\\n|\\r)(\\1)*");
+		env._str2Search = TEXT("^[\\r\\n]+");
 	}
 	env._str4Replace = TEXT("");
 	env._searchType = FindRegex;
@@ -1509,15 +1509,22 @@ void Notepad_plus::removeEmptyLine(bool isBlankContained)
 	_findReplaceDlg.processAll(ProcessReplaceAll, &env, isEntireDoc);
 
 	// remove the last line if it's an empty line.
-	if (isBlankContained)
-	{
-		env._str2Search = TEXT("(\\r?\\n|\\r)^[\\t ]*$");
-	}
-	else
+	auto lastLineDoc = _pEditView->execute(SCI_GETLINECOUNT) - 1;
+	auto str2Search = isBlankContained ? TEXT("[\\r\\n]+^[\\t ]*$|^[\\t ]+$") : TEXT("[\\r\\n]+^$");
+	auto startPos = _pEditView->execute(SCI_POSITIONFROMLINE, lastLineDoc - 1);
+	auto endPos = _pEditView->execute(SCI_GETLENGTH);
+	if (!isEntireDoc)
 	{
-		env._str2Search = TEXT("(\\r?\\n|\\r)^$");
+		startPos = _pEditView->execute(SCI_GETSELECTIONSTART);
+		endPos = _pEditView->execute(SCI_GETSELECTIONEND);
+		auto endLine = _pEditView->execute(SCI_LINEFROMPOSITION, endPos);
+		if (endPos != (_pEditView->execute(SCI_POSITIONFROMLINE, endLine) + _pEditView->execute(SCI_LINELENGTH, endLine)))
+			return;
 	}
-	_findReplaceDlg.processAll(ProcessReplaceAll, &env, isEntireDoc);
+	_pEditView->execute(SCI_SETSEARCHFLAGS, SCFIND_REGEXP|SCFIND_POSIX);
+	auto posFound = _pEditView->searchInTarget(str2Search, lstrlen(str2Search), startPos, endPos);
+	if (posFound >= 0)
+		_pEditView->replaceTarget(TEXT(""), posFound, endPos);
 }
 
 void Notepad_plus::removeDuplicateLines()