[FIXED JENKINS-3265]

Made the in-flight build survive the reload from the disk.

changelog.html

@@ -62,6 +62,9 @@ Upcoming changes</a>
   <li class=bug>
     an in-progress build was dropped from JSON API when lazy-loading was introduced.
     (<a href="https://issues.jenkins-ci.org/browse/JENKINS-15583">issue 15583</a>)
+  <li class=bug>
+    In-progress builds now survive the "reload from disk" administrator action.
+    (<a href="https://issues.jenkins-ci.org/browse/JENKINS-3265">issue 3265</a>)
   <li class=bug>
     Fixed a bad interaction between Windows symlinks and build record lazy loading.
     (<a href="https://issues.jenkins-ci.org/browse/JENKINS-15587">issue 15587</a>)

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

@@ -282,9 +282,20 @@ public abstract class AbstractProject<P extends AbstractProject<P,R>,R extends A
         super.onLoad(parent, name);
 
         RunMap<R> builds = createBuildRunMap();
-        if (this.builds!=null) {
+
+        RunMap<R> currentBuilds = this.builds;
+
+        if (currentBuilds==null) {
+            // are we overwriting what currently exist?
+            // this is primarily when Jenkins is getting reloaded
+            Item current = parent.getItem(name);
+            if (current!=null && current.getClass()==getClass()) {
+                currentBuilds = ((AbstractProject)current).builds;
+            }
+        }
+        if (currentBuilds !=null) {
             // if we are reloading, keep all those that are still building intact
-            for (R r : this.builds.getLoadedBuilds().values()) {
+            for (R r : currentBuilds.getLoadedBuilds().values()) {
                 if (r.isBuilding())
                     builds.put(r);
             }

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

@@ -2505,6 +2505,8 @@ public class Jenkins extends AbstractCIBase implements ModifiableTopLevelItemGro
             }
         });
 
+        final Set<String> loadedNames = Collections.synchronizedSet(new HashSet<String>());
+
         TaskGraphBuilder g = new TaskGraphBuilder();
         Handle loadHudson = g.requires(EXTENSIONS_AUGMENTED).attains(JOB_LOADED).add("Loading global config", new Executable() {
             public void run(Reactor session) throws Exception {
@@ -2527,7 +2529,6 @@ public class Jenkins extends AbstractCIBase implements ModifiableTopLevelItemGro
                 if (slaves == null) slaves = new NodeList();
 
                 clouds.setOwner(Jenkins.this);
-                items.clear();
 
                 // JENKINS-8043: re-add the slaves which were not saved into the config file
                 // and are now missing, but still connected.
@@ -2550,10 +2551,26 @@ public class Jenkins extends AbstractCIBase implements ModifiableTopLevelItemGro
                 public void run(Reactor session) throws Exception {
                     TopLevelItem item = (TopLevelItem) Items.load(Jenkins.this, subdir);
                     items.put(item.getName(), item);
+                    loadedNames.add(item.getName());
                 }
             });
         }
 
+        g.requires(JOB_LOADED).add("Cleaning up old builds",new Executable() {
+            public void run(Reactor reactor) throws Exception {
+                // anything we didn't load from disk, throw them away.
+                // doing this after loading from disk allows newly loaded items
+                // to inspect what already existed in memory (in case of reloading)
+
+                // retainAll doesn't work well because of CopyOnWriteMap implementation, so remove one by one
+                // hopefully there shouldn't be too many of them.
+                for (String name : items.keySet()) {
+                    if (!loadedNames.contains(name))
+                        items.remove(name);
+                }
+            }
+        });
+
         g.requires(JOB_LOADED).add("Finalizing set up",new Executable() {
             public void run(Reactor session) throws Exception {
                 rebuildDependencyGraph();