From e8674fc13d6305fc015511efafa34a89bced4408 Mon Sep 17 00:00:00 2001
From: Abdullah Tahiri <abdullah.tahiri.yo@gmail.com>
Date: Wed, 16 Dec 2020 14:20:02 +0100
Subject: [PATCH] Sketcher: Fix crash on applying angle constraint on arc

=======================================================

The GeoId passed was Constraint::GeoUndef (-2000).

Fixes:
https://forum.freecadweb.org/viewtopic.php?f=10&t=51716&p=458202#p458160
---
 src/Mod/Sketcher/Gui/CommandConstraints.cpp | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/Mod/Sketcher/Gui/CommandConstraints.cpp b/src/Mod/Sketcher/Gui/CommandConstraints.cpp
index 970341f1ea..34dacb6ca6 100644
--- a/src/Mod/Sketcher/Gui/CommandConstraints.cpp
+++ b/src/Mod/Sketcher/Gui/CommandConstraints.cpp
@@ -5987,7 +5987,7 @@ void CmdSketcherConstrainAngle::activated(int iMsg)
             std::swap(PosId1,PosId2);
         }
 
-        if(isBsplinePole(Obj, GeoId1) || isBsplinePole(Obj, GeoId2)) {
+        if(isBsplinePole(Obj, GeoId1) || (GeoId2 != Constraint::GeoUndef && isBsplinePole(Obj, GeoId2))) {
             QMessageBox::warning(Gui::getMainWindow(), QObject::tr("Wrong selection"),
                             QObject::tr("Select an edge that is not a B-spline weight"));
             return;