[JENKINS-8446] pick more consistent default value if someone is installing Jenkins fresh

core/src/main/java/hudson/model/Slave.java

@@ -236,7 +236,7 @@ public abstract class Slave extends Node implements Serializable {
     public FilePath getWorkspaceFor(TopLevelItem item) {
         FilePath r = getWorkspaceRoot();
         if(r==null)     return null;    // offline
-        return r.child(item.getName());
+        return r.child(item.getFullName());
     }
 
     public FilePath getRootPath() {

core/src/main/java/jenkins/model/Jenkins.java

@@ -628,6 +628,11 @@ public class Jenkins extends AbstractCIBase implements ModifiableItemGroup<TopLe
                 throw new IllegalStateException("second instance");
             theInstance = this;
 
+            if (!new File(root,"jobs").exists()) {
+                // if this is a fresh install, use more modern default layout that's consistent with slaves
+                workspaceDir = "${JENKINS_HOME}/workspace/${ITEM_FULLNAME}";
+            }
+
             // doing this early allows InitStrategy to set environment upfront
             final InitStrategy is = InitStrategy.get(Thread.currentThread().getContextClassLoader());