Allow scope of Remove Empty Lines to be limited by an active selection

Close #8428, close #8429

PowerEditor/src/Notepad_plus.cpp

@@ -1400,10 +1400,13 @@ void Notepad_plus::removeEmptyLine(bool isBlankContained)
 		env._str2Search = TEXT("^$(\\r\\n|\\r|\\n)");
 	}
 	env._str4Replace = TEXT("");
-    env._searchType = FindRegex;
-
-	_findReplaceDlg.processAll(ProcessReplaceAll, &env, true);
-
+	env._searchType = FindRegex;
+	auto mainSelStart = _pEditView->execute(SCI_GETSELECTIONSTART);
+	auto mainSelEnd = _pEditView->execute(SCI_GETSELECTIONEND);
+	auto mainSelLength = mainSelEnd - mainSelStart;
+	bool isEntireDoc = mainSelLength == 0;
+	env._isInSelection = !isEntireDoc;
+	_findReplaceDlg.processAll(ProcessReplaceAll, &env, isEntireDoc);
 
 	// remove the last line if it's an empty line.
 	if (isBlankContained)
@@ -1414,7 +1417,7 @@ void Notepad_plus::removeEmptyLine(bool isBlankContained)
 	{
 		env._str2Search = TEXT("(\\r\\n|\\r|\\n)^$");
 	}
-	_findReplaceDlg.processAll(ProcessReplaceAll, &env, true);
+	_findReplaceDlg.processAll(ProcessReplaceAll, &env, isEntireDoc);
 }
 
 void Notepad_plus::removeDuplicateLines()