From 882e48b457b35f2323a4a6cc88ff8017a3e33719 Mon Sep 17 00:00:00 2001
From: Jeff Young <jeff@rokeby.ie>
Date: Tue, 23 May 2023 14:08:53 +0100
Subject: [PATCH] Don't allow collisions with self.

The previous test didn't handle is-self-tests between a hole and
its override in a different NODE.  When calculating the pushout
force we don't remove the via (and its hole) from the current
node until after the calculation, so we end up checking for
collisions between the new (cloned) via's hole and the original
hole in the root node.

Fixes https://gitlab.com/kicad/code/kicad/-/issues/14795

(cherry picked from commit b442d769fd9d472e681aa6dee7e06fe101988222)
---
 pcbnew/router/pns_hole.h   | 2 +-
 pcbnew/router/pns_item.cpp | 4 ++--
 pcbnew/router/pns_item.h   | 7 +++++++
 3 files changed, 10 insertions(+), 3 deletions(-)

diff --git a/pcbnew/router/pns_hole.h b/pcbnew/router/pns_hole.h
index fac9110c8e..57b94f9420 100644
--- a/pcbnew/router/pns_hole.h
+++ b/pcbnew/router/pns_hole.h
@@ -72,7 +72,7 @@ public:
     const SHAPE* Shape() const override { return m_holeShape; }
 
     void SetParentPadVia( ITEM* aParent ) { m_parentPadVia = aParent; }
-    ITEM* ParentPadVia() const { return m_parentPadVia; }
+    ITEM* ParentPadVia() const override { return m_parentPadVia; }
 
     BOARD_ITEM* BoardItem() const override
     {
diff --git a/pcbnew/router/pns_item.cpp b/pcbnew/router/pns_item.cpp
index eab515ca36..913eb1353d 100644
--- a/pcbnew/router/pns_item.cpp
+++ b/pcbnew/router/pns_item.cpp
@@ -65,7 +65,7 @@ bool ITEM::collideSimple( const ITEM* aHead, const NODE* aNode,
 
     //printf( "h %p n %p t %p ctx %p\n", aHead, aNode, this, aCtx );
 
-    if( this == aHead || this == holeH )  // we cannot be self-colliding
+    if( this == aHead )  // we cannot be self-colliding
         return false;
 
     // Special cases for "head" lines with vias attached at the end.  Note that this does not
@@ -86,7 +86,7 @@ bool ITEM::collideSimple( const ITEM* aHead, const NODE* aNode,
 
     // And a special case for the "head" via's hole.
 
-    if( holeH )
+    if( holeH && !HasSameParentPadVia( holeH ) )
         collisionsFound |= collideSimple( holeH, aNode, aCtx );
 
     // Sadly collision routines ignore SHAPE_POLY_LINE widths so we have to pass them in as part
diff --git a/pcbnew/router/pns_item.h b/pcbnew/router/pns_item.h
index 5b1e9a2e78..ea0318ae81 100644
--- a/pcbnew/router/pns_item.h
+++ b/pcbnew/router/pns_item.h
@@ -250,6 +250,13 @@ public:
     void SetIsFreePad( bool aIsFreePad = true ) { m_isFreePad = aIsFreePad; }
     bool IsFreePad() const { return m_isFreePad; }
 
+    virtual ITEM* ParentPadVia() const { return nullptr; }
+    virtual bool HasSameParentPadVia( const ITEM* aOther ) const
+    {
+        return ParentPadVia() && aOther->ParentPadVia()
+                && ParentPadVia()->Parent() == aOther->ParentPadVia()->Parent();
+    }
+
     bool IsVirtual() const
     {
         return m_isVirtual;