Index: src/org/eclipse/update/core/Feature.java
===================================================================
RCS file: /home/eclipse/org.eclipse.update.core/src/org/eclipse/update/core/Feature.java,v
retrieving revision 1.92
diff -u -r1.92 Feature.java
--- src/org/eclipse/update/core/Feature.java	13 May 2004 22:26:58 -0000	1.92
+++ src/org/eclipse/update/core/Feature.java	23 Sep 2004 22:54:06 -0000
@@ -287,6 +287,7 @@
 		IFeatureReference alreadyInstalledFeature = null;
 		IFeatureContentConsumer consumer = null;
 		IPluginEntry[] targetSitePluginEntries = null;
+		ArrayList justInstalledPlugins = new ArrayList();
 
 		try {
 			// determine list of plugins to install
@@ -436,9 +437,12 @@
 					pluginConsumer.store(references[j], subMonitor);
 				}
 
-				InstallRegistry.registerPlugin(pluginsToInstall[i]);
 				if (monitor.isCanceled())
 					abort();
+				else {
+					justInstalledPlugins.add(pluginsToInstall[i]);
+					InstallRegistry.registerPlugin(pluginsToInstall[i]);
+				}
 			}
 
 			// check if we need to install feature files [16718]	
@@ -460,14 +464,18 @@
 						msg + " " + references[i].getIdentifier()); //$NON-NLS-1$
 					consumer.store(references[i], subMonitor);
 				}
-				InstallRegistry.registerFeature(this);
+
+				if (monitor.isCanceled())
+					abort();
+				else
+					InstallRegistry.registerFeature(this);
 			} else {
-				monitor.worked(1);
+				if (monitor.isCanceled())
+					abort();
+				else
+					monitor.worked(1);
 			}
 
-			if (monitor.isCanceled())
-				abort();
-
 			// call handler to complete installation (eg. handle non-plugin entries)
 			handler.completeInstall(consumer);
 			monitorWork(monitor, 1);
@@ -497,6 +505,9 @@
 						// close the log
 						recoveryLog.close(ErrorRecoveryLog.END_INSTALL_LOG);
 					} else {
+						// unregister the just installed plugins
+						for (int i=0; i<justInstalledPlugins.size(); i++)
+							InstallRegistry.unregisterPlugin(((IPluginEntry)justInstalledPlugins.get(i)));
 						consumer.abort();
 					}
 				}
Index: src/org/eclipse/update/internal/core/SiteFilePluginContentConsumer.java
===================================================================
RCS file: /home/eclipse/org.eclipse.update.core/src/org/eclipse/update/internal/core/SiteFilePluginContentConsumer.java,v
retrieving revision 1.36
diff -u -r1.36 SiteFilePluginContentConsumer.java
--- src/org/eclipse/update/internal/core/SiteFilePluginContentConsumer.java	13 May 2004 22:26:58 -0000	1.36
+++ src/org/eclipse/update/internal/core/SiteFilePluginContentConsumer.java	23 Sep 2004 22:54:06 -0000
@@ -141,6 +141,8 @@
 		}
 
 		boolean success = true;
+		InstallRegistry.unregisterPlugin(pluginEntry);
+
 		// delete plugin manifests first
 		for(Iterator it = renames.values().iterator(); it.hasNext();){
 			String originalName = (String) it.next();