From ddec73480799f070f5cf9ea238a1688ce1ee111d Mon Sep 17 00:00:00 2001
From: ParkSuMin <kamalovap@paksurion.ru>
Date: Wed, 10 Dec 2025 20:55:31 +0300
Subject: [PATCH] =?UTF-8?q?=D0=9F=D0=BE=D0=B4=D0=B3=D0=BE=D1=82=D0=BE?=
 =?UTF-8?q?=D0=B2=D0=BA=D0=B0=20=D0=BA=20=D1=81=D0=BE=D0=B7=D0=B4=D0=B0?=
 =?UTF-8?q?=D0=BD=D0=B8=D1=8E=20Arc-=D0=BE=D0=B1=D1=8A=D0=B5=D0=BA=D1=82?=
 =?UTF-8?q?=D0=BE=D0=B2?=
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---
 Canvas.cpp | 14 +++++++-------
 GCS/Geo.h  |  7 +++++--
 2 files changed, 12 insertions(+), 9 deletions(-)

diff --git a/Canvas.cpp b/Canvas.cpp
index 832e56a..8978b10 100644
--- a/Canvas.cpp
+++ b/Canvas.cpp
@@ -34,9 +34,9 @@ Point* Canvas::findPointAt(QPointF pos, qreal tolerance)
 		QPointF p2(*line->p2.x, *line->p2.y);
 
 		if (dist_P2P(p1, pos) <= tolerance)
-			temp = line->p1_ref;
+			temp = line->start_ref;
 		if (dist_P2P(p2, pos) <= tolerance)
-			temp = line->p2_ref;
+			temp = line->end_ref;
 	}
 	return temp;
 }
@@ -104,8 +104,8 @@ void Canvas::mousePressEvent(QMouseEvent* event)
 			current_line->p1.y = y1;
 			current_line->p2.x = x2;
 			current_line->p2.y = y2;
-			current_line->p1_ref = points[points.size() - 2];
-			current_line->p2_ref = points[points.size() - 1];
+			current_line->start_ref = points[points.size() - 2];
+			current_line->end_ref = points[points.size() - 1];
 		}
 		else {
 			*current_line->p2.x = scene.x();
@@ -214,11 +214,11 @@ void Canvas::mousePressEvent(QMouseEvent* event)
 
 		Line *l1 = nullptr, *l2 = nullptr;
 		for (Line* l : lines) {
-			if (l->p1_ref == firstPoint || l->p2_ref == firstPoint) l1 = l;
-			if (l->p1_ref == clickedPoint || l->p2_ref == clickedPoint) l2 = l;
+			if (l->start_ref == firstPoint || l->end_ref == firstPoint) l1 = l;
+			if (l->start_ref == clickedPoint || l->end_ref == clickedPoint) l2 = l;
 		}
 
-		if (l1 == l2 ||
+		if (l1 == l2 && l1 && l2 ||
 			(areCoincident(firstPoint, clickedPoint, true))) 
 		{
 			QMessageBox::warning(this, QString("NO!"), QString("P2P failed"));
diff --git a/GCS/Geo.h b/GCS/Geo.h
index faf6efa..b822cdd 100644
--- a/GCS/Geo.h
+++ b/GCS/Geo.h
@@ -174,6 +174,10 @@ public:
 class Curve
 {
 public:
+    // start in Arc
+    Point* start_ref;
+    // end in Arc
+    Point* end_ref;
     virtual ~Curve()
     {}
     // returns normal vector. The vector should point to the left when one
@@ -228,8 +232,7 @@ public:
     {}
     Point p1;
     Point p2;
-    Point* p1_ref;
-    Point* p2_ref;
+
     DeriVector2 CalculateNormal(const Point& p, const double* derivparam = nullptr) const override;
     DeriVector2 Value(double u, double du, const double* derivparam = nullptr) const override;
     int PushOwnParams(VEC_pD& pvec) override;