Minimal refactoring for a8c3a031

IMO this needs further refactoring - respect separation of concerns:
it's not AbstractProject's call to trigger a node offline

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

@@ -1376,7 +1376,7 @@ public abstract class AbstractProject<P extends AbstractProject<P,R>,R extends A
             workspace.mkdirs();
         } catch (IOException e) {
             // Can't create workspace dir - Is slave disk full ?
-            new DiskSpaceMonitor().data(build.getBuiltOn().toComputer());
+            new DiskSpaceMonitor().markNodeOfflineIfDiskspaceIsTooLow(build.getBuiltOn().toComputer());
             throw e;
         }
         

core/src/main/java/hudson/node_monitors/AbstractDiskSpaceMonitor.java

@@ -2,6 +2,9 @@ package hudson.node_monitors;
 
 import hudson.model.Computer;
 import hudson.node_monitors.DiskSpaceMonitorDescriptor.DiskSpace;
+
+import org.kohsuke.accmod.Restricted;
+import org.kohsuke.accmod.restrictions.NoExternalUse;
 import org.kohsuke.stapler.DataBoundConstructor;
 
 import java.text.ParseException;
@@ -40,18 +43,32 @@ public abstract class AbstractDiskSpaceMonitor extends NodeMonitor {
 
     @Override
     public Object data(Computer c) {
-    	DiskSpace size = (DiskSpace) super.data(c);
+    	DiskSpace size = markNodeOfflineIfDiskspaceIsTooLow(c);
+    	
+    	// mark online (again), if free space is over threshold
+        if(size!=null && size.size > getThresholdBytes() && c.isOffline() && c.getOfflineCause() instanceof DiskSpace)
+            if(this.getClass().equals(((DiskSpace)c.getOfflineCause()).getTrigger()))
+                if(getDescriptor().markOnline(c)) {
+                    LOGGER.warning(Messages.DiskSpaceMonitor_MarkedOnline(c.getName()));
+                }
+        return size;
+    }
+
+    /**
+     * Marks the given node as offline if free disk space is below the configured threshold.
+     * @param c the node
+     * @return the free space
+     * @since 1.521
+     */
+    @Restricted(NoExternalUse.class)
+    public DiskSpace markNodeOfflineIfDiskspaceIsTooLow(Computer c) {
+        DiskSpace size = (DiskSpace) super.data(c);
         if(size!=null && size.size < getThresholdBytes()) {
         	size.setTriggered(this.getClass(), true);
         	if(getDescriptor().markOffline(c,size)) {
         		LOGGER.warning(Messages.DiskSpaceMonitor_MarkedOffline(c.getName()));
         	}
         }
-        if(size!=null && size.size > getThresholdBytes() && c.isOffline() && c.getOfflineCause() instanceof DiskSpace)
-            if(this.getClass().equals(((DiskSpace)c.getOfflineCause()).getTrigger()))
-                if(getDescriptor().markOnline(c)) {
-                    LOGGER.warning(Messages.DiskSpaceMonitor_MarkedOnline(c.getName()));
-                }
         return size;
     }