New solder pads have a plated through hole by default, while pads saved without a hole type stay non-plated; Gerber marks pads with a hole as component pads and pads without one as SMD pads

diylc/diylc-library/src/main/java/org/diylc/components/connectivity/SolderPad.java

@@ -75,7 +75,7 @@ public class SolderPad extends AbstractTransparentComponent<Void>
   private Type type = Type.ROUND;
   private Size holeSize = HOLE_SIZE;
   private PCBLayer layer = PCBLayer._1;
-  private HoleType holeType = HoleType.NTPH;
+  private HoleType holeType = HoleType.PTH;
   private String nodeName = "";
 
   @Override
@@ -97,8 +97,7 @@ public class SolderPad extends AbstractTransparentComponent<Void>
         : new GerberLayer[] {getLayer().toGerberCopperLayer()};
     if (gerberDrawingObserver != null) {
       for (GerberLayer gerberCopperLayer : gerberCopperLayers) {
-        gerberDrawingObserver.startGerberOutput(gerberCopperLayer, GerberFunctions.CONNECTOR_PAD,
-            false);
+        gerberDrawingObserver.startGerberOutput(gerberCopperLayer, getGerberPadFunction(), false);
         gerberDrawingObserver.startGerberOutput(getMaskLayer(gerberCopperLayer), "Material", false);
       }
     }
@@ -178,6 +177,7 @@ public class SolderPad extends AbstractTransparentComponent<Void>
   
   @EditableProperty(name = "Hole Type")
   public HoleType getHoleType() {
+    // pads saved before the hole type existed had non-plated holes; new pads are plated
     if (holeType == null) {
       holeType = HoleType.NTPH;
     }
@@ -226,6 +226,12 @@ public class SolderPad extends AbstractTransparentComponent<Void>
     return HoleType.PTH.equals(getHoleType());
   }
 
+  // a pad with a hole takes a part's lead; one without is a surface mount pad
+  private String getGerberPadFunction() {
+    return HoleType.NONE.equals(getHoleType()) ? GerberFunctions.SMDPAD_CU_DEF
+        : GerberFunctions.COMPONENT_PAD;
+  }
+
   // the mask is opened on the side the copper is on
   private static GerberLayer getMaskLayer(GerberLayer gerberCopperLayer) {
     return gerberCopperLayer == GerberLayer.CopperTop ? GerberLayer.SolderMaskTop

diylc/diylc-library/src/test/java/org/diylc/components/connectivity/SolderPadGerberTest.java

@@ -97,6 +97,23 @@ public class SolderPadGerberTest {
     assertNoCutOut(drawGerber(new Via()));
   }
 
+  @Test
+  public void testPadWithHoleIsComponentPad() {
+    SolderPad pad = new SolderPad();
+    pad.setHoleType(SolderPad.HoleType.NTPH);
+    String gerber = drawGerber(pad).getLayerMap().get(GerberLayer.CopperBot).dumpGerberToString();
+    assertTrue(gerber.contains("TA.AperFunction,ComponentPad*"));
+    assertFalse(gerber.contains("ConnectorPad"));
+  }
+
+  @Test
+  public void testPadWithoutHoleIsSmdPad() {
+    SolderPad pad = new SolderPad();
+    pad.setHoleType(SolderPad.HoleType.NONE);
+    String gerber = drawGerber(pad).getLayerMap().get(GerberLayer.CopperBot).dumpGerberToString();
+    assertTrue(gerber.contains("TA.AperFunction,SMDPad,CuDef*"));
+  }
+
   @Test
   public void testViaIsDrilledOnceAsViaDrill() {
     String excellon = drawGerber(new Via()).getDrillLayerMap().get(GerberLayer.DrillPlated)

diylc/diylc-library/src/test/java/org/diylc/serialization/SolderPadCompatibilityTest.java

@@ -0,0 +1,65 @@
+/*
+
+    DIY Layout Creator (DIYLC).
+    Copyright (c) 2009-2025 held jointly by the individual authors.
+
+    This file is part of DIYLC.
+
+    DIYLC is free software: you can redistribute it and/or modify
+    it under the terms of the GNU General Public License as published by
+    the Free Software Foundation, either version 3 of the License, or
+    (at your option) any later version.
+
+    DIYLC is distributed in the hope that it will be useful,
+    but WITHOUT ANY WARRANTY; without even the implied warranty of
+    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+    GNU General Public License for more details.
+
+    You should have received a copy of the GNU General Public License
+    along with DIYLC.  If not, see <http://www.gnu.org/licenses/>.
+
+*/
+package org.diylc.serialization;
+
+import com.thoughtworks.xstream.XStream;
+import com.thoughtworks.xstream.io.xml.DomDriver;
+
+import org.diylc.components.connectivity.SolderPad;
+import org.junit.Assert;
+import org.junit.Test;
+
+/**
+ * New solder pads are plated, but pads saved before the hole type existed had non-plated holes
+ * and must keep them, so that old projects export and net as before.
+ */
+public class SolderPadCompatibilityTest {
+
+  private static XStream createXStream() {
+    XStream xStream = new XStream(new DomDriver("UTF-8"));
+    ProjectFileManager.configure(xStream);
+    return xStream;
+  }
+
+  @Test
+  public void newPadIsPlated() {
+    Assert.assertEquals(SolderPad.HoleType.PTH, new SolderPad().getHoleType());
+  }
+
+  @Test
+  public void padSavedWithoutHoleTypeLoadsNonPlated() {
+    String xml = createXStream().toXML(new SolderPad());
+    Assert.assertTrue(xml.contains("<holeType>PTH</holeType>"));
+
+    SolderPad loaded =
+        (SolderPad) createXStream().fromXML(xml.replaceAll("\\s*<holeType>PTH</holeType>", ""));
+    Assert.assertEquals(SolderPad.HoleType.NTPH, loaded.getHoleType());
+  }
+
+  @Test
+  public void savedNonPlatedPadStaysNonPlated() {
+    SolderPad pad = new SolderPad();
+    pad.setHoleType(SolderPad.HoleType.NTPH);
+    SolderPad loaded = (SolderPad) createXStream().fromXML(createXStream().toXML(pad));
+    Assert.assertEquals(SolderPad.HoleType.NTPH, loaded.getHoleType());
+  }
+}