From c0a608bfdd98ab7ae376650b376a76421a8fd7f2 Mon Sep 17 00:00:00 2001
From: Jeff Young <jeff@rokeby.ie>
Date: Wed, 20 Mar 2024 18:35:40 +0000
Subject: [PATCH] Keep internal data consistent when changing pad type.

Fixes https://gitlab.com/kicad/code/kicad/-/issues/17493

(cherry picked from commit 859f553c9138fae420c1882a77f53a1ee32afded)
---
 pcbnew/pad.cpp | 28 +++++++++++++++++++++++++---
 1 file changed, 25 insertions(+), 3 deletions(-)

diff --git a/pcbnew/pad.cpp b/pcbnew/pad.cpp
index c6719bd41e..5ff36b3f0e 100644
--- a/pcbnew/pad.cpp
+++ b/pcbnew/pad.cpp
@@ -649,10 +649,32 @@ const BOX2I PAD::GetBoundingBox() const
 
 void PAD::SetAttribute( PAD_ATTRIB aAttribute )
 {
-    m_attribute = aAttribute;
+    if( m_attribute != aAttribute )
+    {
+        m_attribute = aAttribute;
 
-    if( aAttribute == PAD_ATTRIB::SMD )
-        m_drill = VECTOR2I( 0, 0 );
+        switch( aAttribute )
+        {
+        case PAD_ATTRIB::PTH:
+            m_layerMask = PAD::PTHMask();
+            break;
+
+        case PAD_ATTRIB::SMD:
+        case PAD_ATTRIB::CONN:
+            if( m_layerMask.test( F_Cu ) )
+                m_layerMask = { F_Cu };
+            else
+                m_layerMask = { B_Cu };
+
+            m_drill = VECTOR2I( 0, 0 );
+            break;
+
+        case PAD_ATTRIB::NPTH:
+            m_number = wxEmptyString;
+            SetNetCode( NETINFO_LIST::UNCONNECTED );
+            break;
+        }
+    }
 
     SetDirty();
 }