From d3bb31b0ecc42370ee10fdced38d2bec40f8c40b Mon Sep 17 00:00:00 2001
From: xomx <xomx@users.noreply.github.com>
Date: Fri, 3 Oct 2025 22:30:44 +0200
Subject: [PATCH] Fix Monitoring in one view affects selections and position in
 second view

Fix #17046, close #17056
---
 PowerEditor/src/Notepad_plus.cpp | 32 +++++++++++++++++++++++---------
 PowerEditor/src/Notepad_plus.h   |  2 +-
 PowerEditor/src/NppCommands.cpp  |  6 +++---
 PowerEditor/src/NppIO.cpp        | 13 +++++++++----
 4 files changed, 36 insertions(+), 17 deletions(-)

diff --git a/PowerEditor/src/Notepad_plus.cpp b/PowerEditor/src/Notepad_plus.cpp
index dcd29d497..090b47e7f 100644
--- a/PowerEditor/src/Notepad_plus.cpp
+++ b/PowerEditor/src/Notepad_plus.cpp
@@ -9030,19 +9030,33 @@ HBITMAP Notepad_plus::generateSolidColourMenuItemIcon(COLORREF colour)
 	return hNewBitmap;
 }
 
-
-void Notepad_plus::clearChangesHistory()
+void Notepad_plus::clearChangesHistory(int iView)
 {
-	Sci_Position pos = (Sci_Position)::SendMessage(_pEditView->getHSelf(), SCI_GETCURRENTPOS, 0, 0);
-	int chFlags = (int)::SendMessage(_pEditView->getHSelf(), SCI_GETCHANGEHISTORY, 0, 0);
+	// use current view by default
+	ScintillaEditView* pViewToChange = _pEditView;
+	ScintillaEditView* pAnotherView = _pNonEditView;
 
-	_pEditView->execute(SCI_EMPTYUNDOBUFFER);
-	_pEditView->execute(SCI_SETCHANGEHISTORY, SC_CHANGE_HISTORY_DISABLED);
-	_pEditView->execute(SCI_SETCHANGEHISTORY, chFlags);
-	_pEditView->execute(SCI_GOTOPOS, pos);
+	if (iView == MAIN_VIEW)
+	{
+		pViewToChange = &_mainEditView;
+		pAnotherView = &_subEditView;
+	}
+	else if (iView == SUB_VIEW)
+	{
+		pViewToChange = &_subEditView;
+		pAnotherView = &_mainEditView;
+	}
+
+	Sci_Position pos = static_cast<Sci_Position>(::SendMessage(pViewToChange->getHSelf(), SCI_GETCURRENTPOS, 0, 0));
+	int chFlags = static_cast<int>(::SendMessage(pViewToChange->getHSelf(), SCI_GETCHANGEHISTORY, 0, 0));
+
+	pViewToChange->execute(SCI_EMPTYUNDOBUFFER);
+	pViewToChange->execute(SCI_SETCHANGEHISTORY, SC_CHANGE_HISTORY_DISABLED);
+	pViewToChange->execute(SCI_SETCHANGEHISTORY, chFlags);
+	pViewToChange->execute(SCI_GOTOPOS, pos);
 
 	checkUndoState();
-	_pNonEditView->redraw(); // Prevent cloned document visual glichy on another view
+	pAnotherView->redraw(); // Prevent cloned document visual glitch on another view
 }
 
 // Based on https://github.com/notepad-plus-plus/notepad-plus-plus/issues/12248#issuecomment-1258561261.
diff --git a/PowerEditor/src/Notepad_plus.h b/PowerEditor/src/Notepad_plus.h
index f35a22750..48ae88f84 100644
--- a/PowerEditor/src/Notepad_plus.h
+++ b/PowerEditor/src/Notepad_plus.h
@@ -662,7 +662,7 @@ private:
 
 	HBITMAP generateSolidColourMenuItemIcon(COLORREF colour);
 
-	void clearChangesHistory();
+	void clearChangesHistory(int iView);
 	void changedHistoryGoTo(int idGoTo);
 
 	HMENU createMenuFromMenu(HMENU hSourceMenu, const std::vector<int>& commandIds);
diff --git a/PowerEditor/src/NppCommands.cpp b/PowerEditor/src/NppCommands.cpp
index 76fe52769..6e7cd243b 100644
--- a/PowerEditor/src/NppCommands.cpp
+++ b/PowerEditor/src/NppCommands.cpp
@@ -1782,9 +1782,9 @@ void Notepad_plus::command(int id)
 			changedHistoryGoTo(id);
 		    break;
 			
-	    case IDM_SEARCH_CLEAR_CHANGE_HISTORY:
-			clearChangesHistory();
-		    break;
+		case IDM_SEARCH_CLEAR_CHANGE_HISTORY:
+			clearChangesHistory(currentView());
+			break;
 
         case IDM_LANG_USER_DLG :
         {
diff --git a/PowerEditor/src/NppIO.cpp b/PowerEditor/src/NppIO.cpp
index c3708bc3d..97a4506be 100644
--- a/PowerEditor/src/NppIO.cpp
+++ b/PowerEditor/src/NppIO.cpp
@@ -609,15 +609,21 @@ bool Notepad_plus::doReload(BufferID id, bool alert)
 		_subEditView.restoreCurrentPosPreStep();
 	}
 
+	auto svp = NppParameters::getInstance().getSVP();
+
 	// Once reload is complete, activate buffer which will take care of
 	// many settings such as update status bar, clickable link etc.
 	if ( ((currentView() == MAIN_VIEW) && mainVisible) || ((currentView() == SUB_VIEW) && subVisible))
 	{
 		activateBuffer(id, currentView(), true);
+
+		if (svp._isChangeHistoryMarginEnabled || svp._isChangeHistoryIndicatorEnabled)
+			clearChangesHistory(currentView());
 	}
 	else
 	{
 		// handle also the less usual case when the reloaded buffer is not in the current active view
+
 		int originalActiveView = currentView();
 		BufferID originalActiveBufferID = nullptr;
 		if (mainVisible)
@@ -631,11 +637,10 @@ bool Notepad_plus::doReload(BufferID id, bool alert)
 			activateBuffer(id, SUB_VIEW, true);
 		}
 		activateBuffer(originalActiveBufferID, originalActiveView, true); // set back the original
-	}
 
-	auto svp = NppParameters::getInstance().getSVP();
-	if (svp._isChangeHistoryMarginEnabled || svp._isChangeHistoryIndicatorEnabled)
-		clearChangesHistory();
+		if (svp._isChangeHistoryMarginEnabled || svp._isChangeHistoryIndicatorEnabled)
+			clearChangesHistory(otherView());
+	}
 
 	return res;
 }