From 4bf662d031ff4cb55f9d919f4fac85f1e1af7ae1 Mon Sep 17 00:00:00 2001
From: Scott Sumner <30118311+sasumner@users.noreply.github.com>
Date: Wed, 1 Jul 2020 19:50:20 -0400
Subject: [PATCH] Fix condition where Split Lines does one too many lines

Fix #8504, close #8507
---
 PowerEditor/src/NppCommands.cpp | 29 +++++++++++++++++++----------
 1 file changed, 19 insertions(+), 10 deletions(-)

diff --git a/PowerEditor/src/NppCommands.cpp b/PowerEditor/src/NppCommands.cpp
index 7bdfe45d..0ec8646a 100644
--- a/PowerEditor/src/NppCommands.cpp
+++ b/PowerEditor/src/NppCommands.cpp
@@ -1415,18 +1415,27 @@ void Notepad_plus::command(int id)
 			break;
 
 		case IDM_EDIT_SPLIT_LINES:
-			_pEditView->execute(SCI_TARGETFROMSELECTION);
-			if (_pEditView->execute(SCI_GETEDGEMODE) == EDGE_NONE)
+		{
+			pair<int, int> lineRange = _pEditView->getSelectionLinesRange();
+			if (lineRange.first != -1)
 			{
-				_pEditView->execute(SCI_LINESSPLIT);
+				auto anchorPos = _pEditView->execute(SCI_POSITIONFROMLINE, lineRange.first);
+				auto caretPos = _pEditView->execute(SCI_GETLINEENDPOSITION, lineRange.second);
+				_pEditView->execute(SCI_SETSELECTION, caretPos, anchorPos);
+				_pEditView->execute(SCI_TARGETFROMSELECTION);
+				if (_pEditView->execute(SCI_GETEDGEMODE) == EDGE_NONE)
+				{
+					_pEditView->execute(SCI_LINESSPLIT);
+				}
+				else
+				{
+					auto textWidth = _pEditView->execute(SCI_TEXTWIDTH, STYLE_LINENUMBER, reinterpret_cast<LPARAM>("P"));
+					auto edgeCol = _pEditView->execute(SCI_GETEDGECOLUMN);
+					_pEditView->execute(SCI_LINESSPLIT, textWidth * edgeCol);
+				}
 			}
-			else
-			{
-				auto textWidth = _pEditView->execute(SCI_TEXTWIDTH, STYLE_LINENUMBER, reinterpret_cast<LPARAM>("P"));
-				auto edgeCol = _pEditView->execute(SCI_GETEDGECOLUMN);
-				_pEditView->execute(SCI_LINESSPLIT, textWidth * edgeCol);
-			}
-			break;
+		}
+		break;
 
 		case IDM_EDIT_JOIN_LINES:
 			_pEditView->execute(SCI_TARGETFROMSELECTION);