id	summary	reporter	owner	description	type	status	priority	milestone	component	version	resolution	keywords	cc
16854	Stability of created primitive IDs	Don-vip	Don-vip	"This patch should add stability to negative ids of created primitives, when reloading an .osm file.
It needs further tests before merging.

This is needed to edit our internal boundaries file (see #14833, #15036, #15870) and saving command stack state to session files (#12726).

{{{
#!diff
Index: src/org/openstreetmap/josm/io/AbstractReader.java
===================================================================
--- src/org/openstreetmap/josm/io/AbstractReader.java	(revision 14336)
+++ src/org/openstreetmap/josm/io/AbstractReader.java	(working copy)
@@ -13,6 +13,7 @@
 import java.util.List;
 import java.util.Map;
 import java.util.Map.Entry;
+import java.util.OptionalLong;
 import java.util.function.Consumer;
 
 import org.openstreetmap.josm.data.Bounds;
@@ -322,6 +323,10 @@
         } catch (IOException e) {
             throw new IllegalDataException(e);
         } finally {
+            OptionalLong minId = externalIdMap.values().stream().mapToLong(AbstractPrimitive::getUniqueId).min();
+            if (minId.isPresent() && minId.getAsLong() < AbstractPrimitive.currentUniqueId()) {
+                AbstractPrimitive.advanceUniqueId(minId.getAsLong());
+            }
             progressMonitor.finishTask();
             progressMonitor.removeCancelListener(cancelListener);
         }
@@ -603,18 +608,29 @@
         return !Double.isNaN(lat) && !Double.isNaN(lon);
     }
 
+    @SuppressWarnings(""unchecked"")
+    private <T extends OsmPrimitive> T buildPrimitive(PrimitiveData pd) {
+        OsmPrimitive p;
+        if (pd.getUniqueId() < AbstractPrimitive.currentUniqueId()) {
+            p = pd.getType().newInstance(pd.getUniqueId(), true);
+        } else {
+            p = pd.getType().newVersionedInstance(pd.getId(), pd.getVersion());
+        }
+        p.setVisible(pd.isVisible());
+        p.load(pd);
+        externalIdMap.put(pd.getPrimitiveId(), p);
+        return (T) p;
+    }
+
     private Node addNode(NodeData nd, NodeReader nodeReader) throws IllegalDataException {
-        Node n = new Node(nd.getId(), nd.getVersion());
-        n.setVisible(nd.isVisible());
-        n.load(nd);
+        Node n = buildPrimitive(nd);
         nodeReader.accept(n);
-        externalIdMap.put(nd.getPrimitiveId(), n);
         return n;
     }
 
     protected final Node parseNode(double lat, double lon, CommonReader commonReader, NodeReader nodeReader)
             throws IllegalDataException {
-        NodeData nd = new NodeData();
+        NodeData nd = new NodeData(0);
         LatLon ll = null;
         if (areLatLonDefined(lat, lon)) {
             try {
@@ -653,12 +669,9 @@
     }
 
     protected final Way parseWay(CommonReader commonReader, WayReader wayReader) throws IllegalDataException {
-        WayData wd = new WayData();
+        WayData wd = new WayData(0);
         commonReader.accept(wd);
-        Way w = new Way(wd.getId(), wd.getVersion());
-        w.setVisible(wd.isVisible());
-        w.load(wd);
-        externalIdMap.put(wd.getPrimitiveId(), w);
+        Way w = buildPrimitive(wd);
 
         Collection<Long> nodeIds = new ArrayList<>();
         wayReader.accept(w, nodeIds);
@@ -671,12 +684,9 @@
     }
 
     protected final Relation parseRelation(CommonReader commonReader, RelationReader relationReader) throws IllegalDataException {
-        RelationData rd = new RelationData();
+        RelationData rd = new RelationData(0);
         commonReader.accept(rd);
-        Relation r = new Relation(rd.getId(), rd.getVersion());
-        r.setVisible(rd.isVisible());
-        r.load(rd);
-        externalIdMap.put(rd.getPrimitiveId(), r);
+        Relation r = buildPrimitive(rd);
 
         Collection<RelationMemberData> members = new ArrayList<>();
         relationReader.accept(r, members);
}}}"	enhancement	closed	normal	18.12	Core		fixed