Squashed commit of the following:v20130128-050843

304132 - [shared] upgrading shared base causes loss of user installer
plug-ins

commit 8461eae803454c36f6a18013c44e37c20810d141
Merge: 23bc40c c847dee
Author: Pascal Rapicault <pascal@rapicault.net>
Date:   Sun Jan 27 22:11:45 2013 -0500

    Merge branch 'master' into prapicau/sharedInstall-part1

commit 23bc40c4f85b01f37fb0ac23992524a7c8ccd892
Author: Pascal Rapicault (Ericsson) <pascal.rapicault@ericsson.com>
Date:   Sun Jan 27 21:38:07 2013 -0500

    Use constant and fix copyright header

commit bc11d565b32b5b5c8bb5c93e5ea666b1d06b43ff
Author: Pascal Rapicault (Ericsson) <pascal.rapicault@ericsson.com>
Date:   Sun Jan 27 21:33:32 2013 -0500

    Annotate new profile with a base profile timestamp

commit ba4e7abda6e44ad47aead2fade320f9be08b27d5
Author: Pascal Rapicault (Ericsson) <pascal.rapicault@ericsson.com>
Date:   Sun Jan 27 21:32:20 2013 -0500

    Add constants

commit 54c8d356527d1321e25bd837e674b758aa61e248
Author: Krzysztof Daniel <kdaniel@redhat.com>
Date:   Thu Jan 24 13:23:15 2013 +0100

    SimpleConfiguratorImpl refactoring and tests.

commit 6177c466083fb7676ebfe5790bc0951043b3b727
Author: Pascal Rapicault (Ericsson) <pascal.rapicault@ericsson.com>
Date:   Thu Jan 24 11:59:45 2013 -0500

    detection of change in the reconciler

commit f04f46d6d283a6235367872b5eaa7e3e483509ed
Merge: 5243d49 c32f111
Author: Pascal Rapicault <pascal@rapicault.net>
Date:   Thu Jan 24 11:43:01 2013 -0500

    Merge branch 'master' into prapicau/sharedInstall-part1

commit 5243d497142b0f2631bcda8b5fed67d7ce0ddbd5
Author: Pascal Rapicault <pascal@rapicault.net>
Date:   Wed Jan 23 15:26:41 2013 -0500

    always use shared install when the ignoreUserConfig property is set

commit 12eccdad23420e7ba91f99221c852f7e32eb11de
Merge: c68f394 1e9fc23
Author: Pascal Rapicault <pascal@rapicault.net>
Date:   Wed Jan 23 10:29:56 2013 -0500

    Merge branch 'master' into prapicau/sharedInstall-part1

commit c68f394a39c4215ed7ac960495a3c59eb3cf3eee
Author: Pascal Rapicault <pascal@rapicault.net>
Date:   Tue Jan 22 22:24:04 2013 -0500

    Bug 398853 - [UI] installed IU shows as update

commit aa6d632dea7ff54e9ba7c3c7f9f2ecd30afe5906
Author: Pascal Rapicault <pascal@rapicault.net>
Date:   Tue Jan 22 13:50:05 2013 -0500

    Differentiate initial profile creation from reset.

commit 4fb3429ed3fd673d5daf7ca1ce9bf1184a0afcb3
Author: Pascal Rapicault <pascal@rapicault.net>
Date:   Tue Jan 22 13:49:23 2013 -0500

    Only show migration dialog once

commit a34eac29e330a41991d003e2dcd2d8b264d77145
Author: Krzysztof Daniel <kdaniel@redhat.com>
Date:   Mon Jan 21 12:40:36 2013 +0100

    397216: [Shared] Better shared configuration change discovery

    Perform dropins reindexing after master configuration had been changed.

    https://bugs.eclipse.org/bugs/show_bug.cgi?id=397216

commit 6981ca8bd3c1db9ab2dd9484a1f7c8950fcd1abe
Merge: dfec14b 33ca260
Author: Pascal Rapicault <pascal@rapicault.net>
Date:   Mon Jan 21 15:04:28 2013 -0500

    Merge branch 'master' into prapicau/sharedInstall-part1

commit dfec14b67a69b6fa14efb860ef8a986053a58917
Merge: 6067d05 ba5f048
Author: Pascal Rapicault <pascal@rapicault.net>
Date:   Mon Jan 21 11:34:38 2013 -0500

    Merge branch 'master' into prapicau/sharedInstall-part1

commit ba5f048a3ac5563430104adeb173dc4f7dda6eca
Author: Pascal Rapicault <pascal@rapicault.net>
Date:   Mon Jan 21 11:28:20 2013 -0500

    Bug 398539 - Got a NPE trying to add a new update site

commit 6067d05e402fe796debd9d25604cae7026df5b48
Author: Pascal Rapicault <pascal@rapicault.net>
Date:   Fri Jan 18 16:16:18 2013 -0500

    only write timestamp file for shared install

commit 8ab9410d8c797e6a8d2a97e4ba46da3d548440fa
Author: Pascal Rapicault (Ericsson) <pascal.rapicault@ericsson.com>
Date:   Fri Jan 18 13:56:46 2013 -0500

    Cache the fact that the state.properties is missing

commit fefbc5bdec2ce6cdb7fd71b1790bf8abdee8737a
Author: Pascal Rapicault (Ericsson) <pascal.rapicault@ericsson.com>
Date:   Fri Jan 18 13:51:54 2013 -0500

    Fix bug in change detection logic

commit 3de6f8593d5c1b21be3bd21000e34acb945056b1
Author: Pascal Rapicault (Ericsson) <pascal.rapicault@ericsson.com>
Date:   Wed Jan 16 19:50:32 2013 -0500

    Detect changes in the bundles.info

commit 446649c95063dca689f4d2c886b26975a11f3499
Author: Pascal Rapicault <pascal@rapicault.net>
Date:   Tue Jan 15 14:04:57 2013 -0500

    Simple notification to let the user know that the base has changed.

commit e004dc5270abd33a60da9a8d0340409bc8e4a38d
Author: Pascal Rapicault <pascal@rapicault.net>
Date:   Fri Jan 11 14:15:20 2013 +0100

    ignore user config.ini if out of sync with base

commit a0235c0c95b9047e64d6e24c9d8f6b8588087113
Author: Pascal Rapicault (Ericsson) <pascal.rapicault@ericsson.com>
Date:   Wed Dec 12 09:57:36 2012 -0500

    Obtain specific profile state properties without locking

commit 1d0f129ca70716e7a181631e1ba0e71f16e35e08
Author: Pascal Rapicault (Ericsson) <pascal.rapicault@ericsson.com>
Date:   Mon Dec 10 16:06:38 2012 -0500

    Remember the timestamp of the base config.ini

commit 3134caecfd244fd88386f3ce4bd1a6fc71fe8007
Author: Pascal Rapicault (Ericsson) <pascal.rapicault@ericsson.com>
Date:   Wed Dec 5 16:21:50 2012 -0500

    Support to ignore the existing profile if the base has changed

commit 7f0ba4e643f40bc0143617b93b2238388d38216d
Author: Pascal Rapicault (Ericsson) <pascal.rapicault@ericsson.com>
Date:   Tue Dec 4 11:23:37 2012 -0500

    Remove externalization warning

19 files changed, 667 insertions, 112 deletions

diff --git a/bundles/org.eclipse.equinox.frameworkadmin.equinox/src/org/eclipse/equinox/internal/frameworkadmin/equinox/EquinoxFwConfigFileParser.java b/bundles/org.eclipse.equinox.frameworkadmin.equinox/src/org/eclipse/equinox/internal/frameworkadmin/equinox/EquinoxFwConfigFileParser.java
index 7f19233a7..3f7e4ffd8 100644
--- a/bundles/org.eclipse.equinox.frameworkadmin.equinox/src/org/eclipse/equinox/internal/frameworkadmin/equinox/EquinoxFwConfigFileParser.java
+++ b/bundles/org.eclipse.equinox.frameworkadmin.equinox/src/org/eclipse/equinox/internal/frameworkadmin/equinox/EquinoxFwConfigFileParser.java
@@ -1,5 +1,5 @@
 /*******************************************************************************
- * Copyright (c) 2007, 2011 IBM Corporation and others.
+ * Copyright (c) 2007, 2013 IBM Corporation and others.
  * All rights reserved. This program and the accompanying materials
  * are made available under the terms of the Eclipse Public License v1.0
  * which accompanies this distribution, and is available at
@@ -7,6 +7,8 @@
  *
  * Contributors:
  *     IBM Corporation - initial API and implementation
+ *     Ericsson AB (Pascal Rapicault) - Bug 397216 -[Shared] Better shared
+ *                                      configuration change discovery
  *******************************************************************************/
 package org.eclipse.equinox.internal.frameworkadmin.equinox;
 
@@ -30,6 +32,9 @@ public class EquinoxFwConfigFileParser {
 	private static final String KEY_ORG_ECLIPSE_EQUINOX_SIMPLECONFIGURATOR_CONFIGURL = "org.eclipse.equinox.simpleconfigurator.configUrl"; //$NON-NLS-1$
 	private static final String REFERENCE_SCHEME = "reference:"; //$NON-NLS-1$
 	private static final String FILE_PROTOCOL = "file:"; //$NON-NLS-1$
+	private static final String BASE_TIMESTAMP_FILE_CONFIGINI = ".baseConfigIniTimestamp"; //$NON-NLS-1$
+	private static final String KEY_CONFIGINI_TIMESTAMP = "configIniTimestamp"; //$NON-NLS-1$
+
 	private static boolean DEBUG = false;
 
 	public EquinoxFwConfigFileParser(BundleContext context) {
@@ -198,6 +203,7 @@ public class EquinoxFwConfigFileParser {
 		if (inputFile.isDirectory())
 			throw new IllegalArgumentException(NLS.bind(Messages.exception_inputFileIsDirectory, inputFile));
 
+		boolean baseHasChanged = false;
 		//Initialize data structures
 		ConfigData configData = manipulator.getConfigData();
 		LauncherData launcherData = manipulator.getLauncherData();
@@ -208,9 +214,15 @@ public class EquinoxFwConfigFileParser {
 		Properties props = loadProperties(inputFile);
 
 		// load shared configuration properties
-		Properties sharedConfigProperties = getSharedConfiguration(props.getProperty(EquinoxConstants.PROP_SHARED_CONFIGURATION_AREA), ParserUtils.getOSGiInstallArea(Arrays.asList(manipulator.getLauncherData().getProgramArgs()), props, manipulator.getLauncherData()));
+		Properties sharedConfigProperties = getSharedConfiguration(ParserUtils.getOSGiInstallArea(Arrays.asList(manipulator.getLauncherData().getProgramArgs()), props, manipulator.getLauncherData()), props.getProperty(EquinoxConstants.PROP_SHARED_CONFIGURATION_AREA));
 		if (sharedConfigProperties != null) {
-			sharedConfigProperties.putAll(props);
+			baseHasChanged = hasBaseChanged(inputFile, manipulator, props);
+			if (!baseHasChanged)
+				sharedConfigProperties.putAll(props);
+			else {
+				sharedConfigProperties.put(EquinoxConstants.PROP_SHARED_CONFIGURATION_AREA, props.get(EquinoxConstants.PROP_SHARED_CONFIGURATION_AREA));
+			}
+
 			props = sharedConfigProperties;
 		}
 
@@ -222,7 +234,9 @@ public class EquinoxFwConfigFileParser {
 		//readLauncherPath(props, rootURI);
 		readp2DataArea(props, configArea);
 		readSimpleConfiguratorURL(props, configArea);
-		readBundlesList(manipulator, ParserUtils.getOSGiInstallArea(Arrays.asList(launcherData.getProgramArgs()), props, launcherData).toURI(), props);
+
+		if (!baseHasChanged)
+			readBundlesList(manipulator, ParserUtils.getOSGiInstallArea(Arrays.asList(launcherData.getProgramArgs()), props, launcherData).toURI(), props);
 		readInitialStartLeve(configData, props);
 		readDefaultStartLevel(configData, props);
 
@@ -236,6 +250,21 @@ public class EquinoxFwConfigFileParser {
 		Log.log(LogService.LOG_INFO, NLS.bind(Messages.log_configFile, inputFile.getAbsolutePath()));
 	}
 
+	private boolean hasBaseChanged(File configIni, Manipulator manipulator, Properties configProps) {
+		LauncherData launcherData = manipulator.getLauncherData();
+		File sharedConfigIni = findSharedConfigIniFile(ParserUtils.getOSGiInstallArea(Arrays.asList(launcherData.getProgramArgs()), configProps, launcherData), configProps.getProperty(EquinoxConstants.PROP_SHARED_CONFIGURATION_AREA));
+		File timestampFile = new File(configIni.getParentFile(), BASE_TIMESTAMP_FILE_CONFIGINI);
+		Properties timestamps;
+		try {
+			timestamps = loadProperties(timestampFile);
+		} catch (FileNotFoundException e) {
+			return false;
+		} catch (IOException e) {
+			return false;
+		}
+		return !String.valueOf(sharedConfigIni.lastModified()).equals(timestamps.getProperty(KEY_CONFIGINI_TIMESTAMP));
+	}
+
 	private void readDefaultStartLevel(ConfigData configData, Properties props) {
 		if (props.getProperty(EquinoxConstants.PROP_BUNDLES_STARTLEVEL) != null)
 			configData.setInitialBundleStartLevel(Integer.parseInt(props.getProperty(EquinoxConstants.PROP_BUNDLES_STARTLEVEL)));
@@ -293,7 +322,8 @@ public class EquinoxFwConfigFileParser {
 			props.load(is);
 		} finally {
 			try {
-				is.close();
+				if (is != null)
+					is.close();
 			} catch (IOException e) {
 				Log.log(LogService.LOG_WARNING, NLS.bind(Messages.log_failed_reading_properties, inputFile));
 			}
@@ -302,7 +332,18 @@ public class EquinoxFwConfigFileParser {
 		return props;
 	}
 
-	private File findSharedConfigIniFile(URL rootURL, String sharedConfigurationArea) {
+	private File findSharedConfigIniFile(File base, String sharedConfigurationArea) {
+		if (base == null)
+			return null;
+		URL rootURL;
+		try {
+			rootURL = base.toURL();
+		} catch (MalformedURLException e1) {
+			return null;
+		}
+		if (rootURL == null)
+			return null;
+
 		URL sharedConfigurationURL = null;
 		try {
 			sharedConfigurationURL = new URL(sharedConfigurationArea);
@@ -415,7 +456,6 @@ public class EquinoxFwConfigFileParser {
 				outputFile = new File(outputFile, EquinoxConstants.CONFIG_INI);
 			}
 		}
-		String header = "This configuration file was written by: " + this.getClass().getName(); //$NON-NLS-1$
 
 		Properties configProps = new Properties();
 		//URI rootURI = launcherData.getLauncher() != null ? launcherData.getLauncher().getParentFile().toURI() : null;
@@ -459,13 +499,18 @@ public class EquinoxFwConfigFileParser {
 				Log.log(LogService.LOG_INFO, this, "saveFwConfig()", NLS.bind(Messages.log_renameSuccessful, outputFile, dest)); //$NON-NLS-1$
 			}
 
+		filterPropertiesFromSharedArea(configProps, manipulator);
+		saveProperties(outputFile, configProps);
+		rememberSharedConfigurationTimestamp(configProps, manipulator, outputFile.getParentFile());
+	}
+
+	private void saveProperties(File outputFile, Properties configProps) throws IOException {
+		String header = "This configuration file was written by: " + this.getClass().getName(); //$NON-NLS-1$
 		FileOutputStream out = null;
 		try {
 			out = new FileOutputStream(outputFile);
-			//			configProps = makeRelative(configProps, launcherData.getLauncher().getParentFile().toURI(), fwJar, outputFile.getParentFile(), getOSGiInstallArea(manipulator.getLauncherData()));
-			filterPropertiesFromSharedArea(configProps, manipulator);
 			configProps.store(out, header);
-			Log.log(LogService.LOG_INFO, NLS.bind(Messages.log_fwConfigSave, outputFile));
+			Log.log(LogService.LOG_INFO, NLS.bind(Messages.log_propertiesSaved, outputFile));
 		} finally {
 			try {
 				out.flush();
@@ -473,14 +518,13 @@ public class EquinoxFwConfigFileParser {
 			} catch (IOException e) {
 				e.printStackTrace();
 			}
-			out = null;
 		}
 	}
 
 	private void filterPropertiesFromSharedArea(Properties configProps, Manipulator manipulator) {
 		LauncherData launcherData = manipulator.getLauncherData();
 		//Remove from the config file that we are about to write the properties that are unchanged compared to what is in the base
-		Properties sharedConfigProperties = getSharedConfiguration(configProps.getProperty(EquinoxConstants.PROP_SHARED_CONFIGURATION_AREA), ParserUtils.getOSGiInstallArea(Arrays.asList(launcherData.getProgramArgs()), configProps, launcherData));
+		Properties sharedConfigProperties = getSharedConfiguration(ParserUtils.getOSGiInstallArea(Arrays.asList(launcherData.getProgramArgs()), configProps, launcherData), configProps.getProperty(EquinoxConstants.PROP_SHARED_CONFIGURATION_AREA));
 		if (sharedConfigProperties == null)
 			return;
 		Enumeration keys = configProps.propertyNames();
@@ -549,16 +593,28 @@ public class EquinoxFwConfigFileParser {
 		}
 	}
 
-	private Properties getSharedConfiguration(String sharedConfigurationArea, File baseFile) {
-		if (sharedConfigurationArea == null)
-			return null;
-		File sharedConfigIni;
+	private void rememberSharedConfigurationTimestamp(Properties configProps, Manipulator manipulator, File folder) throws IOException {
+		LauncherData launcherData = manipulator.getLauncherData();
+		//Remove from the config file that we are about to write the properties that are unchanged compared to what is in the base
+		File sharedConfigIni = findSharedConfigIniFile(ParserUtils.getOSGiInstallArea(Arrays.asList(launcherData.getProgramArgs()), configProps, launcherData), configProps.getProperty(EquinoxConstants.PROP_SHARED_CONFIGURATION_AREA));
+		if (sharedConfigIni == null)
+			return;
+		File timestampFile = new File(folder, BASE_TIMESTAMP_FILE_CONFIGINI);
+		Properties timestamps;
 		try {
-			sharedConfigIni = findSharedConfigIniFile(baseFile.toURL(), sharedConfigurationArea);
-		} catch (MalformedURLException e) {
-			return null;
+			timestamps = loadProperties(timestampFile);
+		} catch (IOException e) {
+			timestamps = new Properties();
 		}
-		if (sharedConfigIni != null && sharedConfigIni.exists())
+		timestamps.setProperty(KEY_CONFIGINI_TIMESTAMP, String.valueOf(sharedConfigIni.lastModified()));
+		saveProperties(timestampFile, timestamps);
+	}
+
+	private Properties getSharedConfiguration(File baseFile, String sharedConfigurationArea) {
+		if (sharedConfigurationArea == null)
+			return null;
+		File sharedConfigIni = findSharedConfigIniFile(baseFile, sharedConfigurationArea);
+		if (sharedConfigIni != null && sharedConfigIni.exists()) {
 			try {
 				return loadProperties(sharedConfigIni);
 			} catch (FileNotFoundException e) {
@@ -566,6 +622,7 @@ public class EquinoxFwConfigFileParser {
 			} catch (IOException e) {
 				return null;
 			}
+		}
 		return null;
 	}
 }
diff --git a/bundles/org.eclipse.equinox.frameworkadmin.equinox/src/org/eclipse/equinox/internal/frameworkadmin/equinox/Messages.java b/bundles/org.eclipse.equinox.frameworkadmin.equinox/src/org/eclipse/equinox/internal/frameworkadmin/equinox/Messages.java
index 2453f7ba3..66920c277 100644
--- a/bundles/org.eclipse.equinox.frameworkadmin.equinox/src/org/eclipse/equinox/internal/frameworkadmin/equinox/Messages.java
+++ b/bundles/org.eclipse.equinox.frameworkadmin.equinox/src/org/eclipse/equinox/internal/frameworkadmin/equinox/Messages.java
@@ -31,7 +31,7 @@ public class Messages extends NLS {
 	public static String log_configFile;
 	public static String log_configProps;
 	public static String log_renameSuccessful;
-	public static String log_fwConfigSave;
+	public static String log_propertiesSaved;
 	public static String log_launcherConfigSave;
 	public static String log_shared_config_url;
 	public static String log_shared_config_relative_url;
diff --git a/bundles/org.eclipse.equinox.frameworkadmin.equinox/src/org/eclipse/equinox/internal/frameworkadmin/equinox/messages.properties b/bundles/org.eclipse.equinox.frameworkadmin.equinox/src/org/eclipse/equinox/internal/frameworkadmin/equinox/messages.properties
index a5d0d5083..3c84f4dcd 100644
--- a/bundles/org.eclipse.equinox.frameworkadmin.equinox/src/org/eclipse/equinox/internal/frameworkadmin/equinox/messages.properties
+++ b/bundles/org.eclipse.equinox.frameworkadmin.equinox/src/org/eclipse/equinox/internal/frameworkadmin/equinox/messages.properties
@@ -26,7 +26,7 @@ exception_errorReadingFile = An error occured while reading {0}.
 log_configFile= Configuration file ({0}) has been read successfully.
 log_configProps= Configuration properties is empty.
 log_renameSuccessful= Successfully renamed {0} to {1}.
-log_fwConfigSave= Framework Configuration was saved successfully in {0}.
+log_propertiesSaved= File {0} was saved successfully.
 log_launcherConfigSave= Launcher Configuration was saved successfully in {0}.
 log_shared_config_url=Failed creating shared configuration url for {0}.
 log_shared_config_relative_url=Failed creating shared configuration url for root: {0} and sharedConfiguration: {1}.
diff --git a/bundles/org.eclipse.equinox.frameworkadmin.test/dataFile/sharedconfiguration/ignoreUserConfig/config.ini b/bundles/org.eclipse.equinox.frameworkadmin.test/dataFile/sharedconfiguration/ignoreUserConfig/config.ini
new file mode 100644
index 000000000..cb5fd8609
--- /dev/null
+++ b/bundles/org.eclipse.equinox.frameworkadmin.test/dataFile/sharedconfiguration/ignoreUserConfig/config.ini
@@ -0,0 +1 @@
+sharedKey=sharedValue
\ No newline at end of file
diff --git a/bundles/org.eclipse.equinox.frameworkadmin.test/dataFile/sharedconfiguration/ignoreUserConfig/user-config.ini b/bundles/org.eclipse.equinox.frameworkadmin.test/dataFile/sharedconfiguration/ignoreUserConfig/user-config.ini
new file mode 100644
index 000000000..8797ba532
--- /dev/null
+++ b/bundles/org.eclipse.equinox.frameworkadmin.test/dataFile/sharedconfiguration/ignoreUserConfig/user-config.ini
@@ -0,0 +1,3 @@
+osgi.sharedConfiguration.area=file\:configuration/
+userKey=userValue
+
diff --git a/bundles/org.eclipse.equinox.frameworkadmin.test/src/org/eclipse/equinox/frameworkadmin/tests/SharedConfigurationTest.java b/bundles/org.eclipse.equinox.frameworkadmin.test/src/org/eclipse/equinox/frameworkadmin/tests/SharedConfigurationTest.java
index 134d7bec0..0d0eba503 100644
--- a/bundles/org.eclipse.equinox.frameworkadmin.test/src/org/eclipse/equinox/frameworkadmin/tests/SharedConfigurationTest.java
+++ b/bundles/org.eclipse.equinox.frameworkadmin.test/src/org/eclipse/equinox/frameworkadmin/tests/SharedConfigurationTest.java
@@ -1,5 +1,5 @@
 /*******************************************************************************
- * Copyright (c) 2008, 2010 IBM Corporation and others.
+ * Copyright (c) 2008, 2013 IBM Corporation and others.
  * All rights reserved. This program and the accompanying materials
  * are made available under the terms of the Eclipse Public License v1.0
  * which accompanies this distribution, and is available at
@@ -7,20 +7,29 @@
  *
  * Contributors:
  *     IBM Corporation - initial API and implementation
+ *     Ericsson AB (Pascal Rapicault) - Improve shared install
  *******************************************************************************/
 package org.eclipse.equinox.frameworkadmin.tests;
 
-import java.io.File;
-import java.io.IOException;
+import java.io.*;
+import java.net.URISyntaxException;
+import java.util.Properties;
+import org.eclipse.core.runtime.FileLocator;
+import org.eclipse.core.runtime.URIUtil;
+import org.eclipse.equinox.frameworkadmin.BundleInfo;
+import org.eclipse.equinox.internal.frameworkadmin.equinox.Log;
+import org.eclipse.equinox.internal.frameworkadmin.equinox.Messages;
 import org.eclipse.equinox.internal.provisional.frameworkadmin.*;
+import org.eclipse.osgi.util.NLS;
 import org.osgi.framework.BundleException;
+import org.osgi.service.log.LogService;
 
 public class SharedConfigurationTest extends AbstractFwkAdminTest {
 
 	public SharedConfigurationTest(String name) {
 		super(name);
 	}
-	
+
 	public void testDefaultConfiguration() throws IllegalStateException, FrameworkAdminRuntimeException, IOException, BundleException {
 		startSimpleConfiguratorManipulator();
 		FrameworkAdmin fwkAdmin = getEquinoxFrameworkAdmin();
@@ -30,19 +39,19 @@ public class SharedConfigurationTest extends AbstractFwkAdminTest {
 		File defaultConfigurationFolder = new File(installFolder, "configuration");
 		defaultConfigurationFolder.mkdirs();
 		copy("creating shared config.ini", getTestData("", "dataFile/sharedconfiguration/config.ini"), new File(defaultConfigurationFolder, "config.ini"));
-		
+
 		String launcherName = "foo";
 
 		LauncherData launcherData = manipulator.getLauncherData();
 		launcherData.setFwConfigLocation(defaultConfigurationFolder);
 		launcherData.setLauncher(new File(installFolder, launcherName));
-		
+
 		try {
 			manipulator.load();
 		} catch (IllegalStateException e) {
 			//TODO We ignore the framework JAR location not set exception
 		}
-		
+
 		assertEquals("false", manipulator.getConfigData().getProperty("config.shared"));
 		assertEquals("true", manipulator.getConfigData().getProperty("from.parent"));
 	}
@@ -59,23 +68,23 @@ public class SharedConfigurationTest extends AbstractFwkAdminTest {
 		File userConfigurationFolder = new File(installFolder, "user/configuration");
 		userConfigurationFolder.mkdirs();
 		copy("creating shared config.ini", getTestData("", "dataFile/sharedconfiguration/user-config.ini"), new File(userConfigurationFolder, "config.ini"));
-		
+
 		String launcherName = "foo";
 
 		LauncherData launcherData = manipulator.getLauncherData();
 		launcherData.setFwConfigLocation(userConfigurationFolder);
 		launcherData.setLauncher(new File(installFolder, launcherName));
-		
+
 		try {
 			manipulator.load();
 		} catch (IllegalStateException e) {
 			//TODO We ignore the framework JAR location not set exception
 		}
-		
+
 		assertEquals("true", manipulator.getConfigData().getProperty("config.shared"));
 		assertEquals("true", manipulator.getConfigData().getProperty("from.parent"));
 	}
-	
+
 	public void testNotSharedConfiguration() throws IllegalStateException, FrameworkAdminRuntimeException, IOException, BundleException {
 		startSimpleConfiguratorManipulator();
 		FrameworkAdmin fwkAdmin = getEquinoxFrameworkAdmin();
@@ -88,20 +97,109 @@ public class SharedConfigurationTest extends AbstractFwkAdminTest {
 		File userConfigurationFolder = new File(installFolder, "user/configuration");
 		userConfigurationFolder.mkdirs();
 		copy("creating shared config.ini", getTestData("", "dataFile/sharedconfiguration/user-noshare-config.ini"), new File(userConfigurationFolder, "config.ini"));
-		
+
 		String launcherName = "foo";
 
 		LauncherData launcherData = manipulator.getLauncherData();
 		launcherData.setFwConfigLocation(userConfigurationFolder);
 		launcherData.setLauncher(new File(installFolder, launcherName));
-		
+
 		try {
 			manipulator.load();
 		} catch (IllegalStateException e) {
 			//TODO We ignore the framework JAR location not set exception
 		}
-		
+
 		assertEquals("false", manipulator.getConfigData().getProperty("config.shared"));
 		assertEquals(null, manipulator.getConfigData().getProperty("from.parent"));
 	}
+
+	public void testConfigIniTimestamp() throws BundleException, FrameworkAdminRuntimeException, IOException, URISyntaxException {
+		startSimpleConfiguratorManipulator();
+		FrameworkAdmin fwkAdmin = getEquinoxFrameworkAdmin();
+		Manipulator manipulator = fwkAdmin.getManipulator();
+
+		File installFolder = Activator.getContext().getDataFile(SharedConfigurationTest.class.getName());
+		File defaultConfigurationFolder = new File(installFolder, "configuration");
+		defaultConfigurationFolder.mkdirs();
+		copy("creating shared config.ini", getTestData("", "dataFile/sharedconfiguration/config.ini"), new File(defaultConfigurationFolder, "config.ini"));
+		File userConfigurationFolder = new File(installFolder, "user/configuration");
+		userConfigurationFolder.mkdirs();
+		copy("creating shared config.ini", getTestData("", "dataFile/sharedconfiguration/user-config.ini"), new File(userConfigurationFolder, "config.ini"));
+
+		String launcherName = "foo";
+
+		LauncherData launcherData = manipulator.getLauncherData();
+		launcherData.setFwConfigLocation(userConfigurationFolder);
+		launcherData.setLauncher(new File(installFolder, launcherName));
+
+		try {
+			manipulator.load();
+		} catch (IllegalStateException e) {
+			//TODO We ignore the framework JAR location not set exception
+		}
+
+		BundleInfo osgiBi = new BundleInfo("org.eclipse.osgi", "3.3.1", URIUtil.toURI(FileLocator.resolve(Activator.getContext().getBundle().getEntry("dataFile/org.eclipse.osgi.jar"))), 0, true);
+		BundleInfo configuratorBi = new BundleInfo("org.eclipse.equinox.simpleconfigurator", "1.0.0", URIUtil.toURI(FileLocator.resolve(Activator.getContext().getBundle().getEntry("dataFile/org.eclipse.equinox.simpleconfigurator.jar"))), 1, true);
+
+		manipulator.getConfigData().addBundle(osgiBi);
+		manipulator.getConfigData().addBundle(configuratorBi);
+
+		manipulator.save(false);
+		File baseTimestamp = new File(userConfigurationFolder, ".baseTimestamps");
+		assertIsFile(baseTimestamp);
+		assertContent(baseTimestamp, Long.toString(new File(defaultConfigurationFolder, "config.ini").lastModified()));
+	}
+
+	public void testConfigurationIgnoredWhenChanged() throws BundleException, FrameworkAdminRuntimeException, IOException {
+		startSimpleConfiguratorManipulator();
+		FrameworkAdmin fwkAdmin = getEquinoxFrameworkAdmin();
+		Manipulator manipulator = fwkAdmin.getManipulator();
+
+		//setup the files
+		File installFolder = Activator.getContext().getDataFile(SharedConfigurationTest.class.getName());
+		File defaultConfigurationFolder = new File(installFolder, "configuration");
+		defaultConfigurationFolder.mkdirs();
+		copy("creating shared config.ini", getTestData("", "dataFile/sharedconfiguration/ignoreUserConfig/config.ini"), new File(defaultConfigurationFolder, "config.ini"));
+		File userConfigurationFolder = new File(installFolder, "user/configuration");
+		userConfigurationFolder.mkdirs();
+		copy("creating shared config.ini", getTestData("", "dataFile/sharedconfiguration/ignoreUserConfig/user-config.ini"), new File(userConfigurationFolder, "config.ini"));
+		
+		//setup the timestamp 
+		Properties p = new Properties();
+		p.setProperty("configIniTimestamp", Long.toString(new File(defaultConfigurationFolder, "config.ini").lastModified()));
+		saveProperties(new File(userConfigurationFolder, ".baseTimestamps"), p);
+
+		String launcherName = "foo";
+
+		LauncherData launcherData = manipulator.getLauncherData();
+		launcherData.setFwConfigLocation(userConfigurationFolder);
+		launcherData.setLauncher(new File(installFolder, launcherName));
+
+		try {
+			manipulator.load();
+		} catch (IllegalStateException e) {
+			//TODO We ignore the framework JAR location not set exception
+		}
+
+		assertNull(manipulator.getConfigData().getProperty("userKey"));
+		assertEquals("sharedValue", manipulator.getConfigData().getProperty("sharedKey"));
+	}
+
+	private void saveProperties(File outputFile, Properties configProps) throws IOException {
+		String header = "This configuration file was written by: " + this.getClass().getName(); //$NON-NLS-1$
+		FileOutputStream out = null;
+		try {
+			out = new FileOutputStream(outputFile);
+			configProps.store(out, header);
+			Log.log(LogService.LOG_INFO, NLS.bind(Messages.log_propertiesSaved, outputFile));
+		} finally {
+			try {
+				out.flush();
+				out.close();
+			} catch (IOException e) {
+				e.printStackTrace();
+			}
+		}
+	}
 }
diff --git a/bundles/org.eclipse.equinox.p2.engine/src/org/eclipse/equinox/internal/p2/engine/SimpleProfileRegistry.java b/bundles/org.eclipse.equinox.p2.engine/src/org/eclipse/equinox/internal/p2/engine/SimpleProfileRegistry.java
index 945ec048e..9e0265404 100644
--- a/bundles/org.eclipse.equinox.p2.engine/src/org/eclipse/equinox/internal/p2/engine/SimpleProfileRegistry.java
+++ b/bundles/org.eclipse.equinox.p2.engine/src/org/eclipse/equinox/internal/p2/engine/SimpleProfileRegistry.java
@@ -1,12 +1,12 @@
 /*******************************************************************************
- * Copyright (c) 2007, 2012 IBM Corporation and others. All rights reserved. This
+ * Copyright (c) 2007, 2013 IBM Corporation and others. All rights reserved. This
  * program and the accompanying materials are made available under the terms of
  * the Eclipse Public License v1.0 which accompanies this distribution, and is
  * available at http://www.eclipse.org/legal/epl-v10.html
  * 
  * Contributors: 
  *     IBM Corporation - initial API and implementation
- *     Ericsson AB (Pascal Rapicault) - reading preferences from base in shared install
+ *     Ericsson AB - ongoing development
  ******************************************************************************/
 package org.eclipse.equinox.internal.p2.engine;
 
@@ -38,6 +38,8 @@ import org.xml.sax.SAXException;
 
 public class SimpleProfileRegistry implements IProfileRegistry, IAgentService {
 
+	private static final String SIMPLE_PROFILE_REGISTRY_INTERNAL = "_simpleProfileRegistry_internal_";
+	private static final String ECLIPSE_IGNORE_USER_CONFIGURATION = "eclipse.ignoreUserConfiguration"; //$NON-NLS-1$
 	private static final String PROFILE_REGISTRY = "profile registry"; //$NON-NLS-1$
 	private static final String PROFILE_PROPERTIES_FILE = "state.properties"; //$NON-NLS-1$
 
@@ -168,7 +170,7 @@ public class SimpleProfileRegistry implements IProfileRegistry, IAgentService {
 	}
 
 	public synchronized String toString() {
-		return "Profile registry for location: " + store.getAbsolutePath() + "\n" + getProfileMap().toString(); //$NON-NLS-1$
+		return "Profile registry for location: " + store.getAbsolutePath() + "\n" + getProfileMap().toString(); //$NON-NLS-1$ //$NON-NLS-2$
 	}
 
 	public synchronized IProfile getProfile(String id) {
@@ -243,12 +245,57 @@ public class SimpleProfileRegistry implements IProfileRegistry, IAgentService {
 		if (SELF.equals(id))
 			id = self;
 		Profile profile = getProfileMap().get(id);
-		if (profile == null && self != null && self.equals(id))
-			profile = createSurrogateProfile(id);
-
+		if (self != null && self.equals(id)) {
+			boolean resetProfile = false;
+			if (profile != null && ignoreExistingProfile(profile)) {
+				internalSetProfileStateProperty(profile, profile.getTimestamp(), IProfile.STATE_PROP_SHARED_INSTALL, IProfile.STATE_SHARED_INSTALL_VALUE_BEFOREFLUSH);
+				profile = null;
+				resetProfile = true;
+			}
+			if (profile == null) {
+				profile = createSurrogateProfile(id);
+				if (resetProfile) {
+					//Now that we created a new profile. Tag it, override the property and register the timestamp in the agent registry for pickup by other  
+					internalSetProfileStateProperty(profile, profile.getTimestamp(), IProfile.STATE_PROP_SHARED_INSTALL, IProfile.STATE_SHARED_INSTALL_VALUE_NEW);
+					internalSetProfileStateProperty(profile, profile.getTimestamp(), SIMPLE_PROFILE_REGISTRY_INTERNAL + getBaseTimestamp(profile.getProfileId()), getBaseTimestamp(id));
+					System.setProperty(ECLIPSE_IGNORE_USER_CONFIGURATION, "profileFlushed"); //$NON-NLS-1$
+					agent.registerService(SERVICE_SHARED_INSTALL_NEW_TIMESTAMP, Long.toString(profile.getTimestamp()));
+				} else {
+					//This is the first time we create the shared profile. Tag it as such and also remember the timestamp of the base
+					internalSetProfileStateProperty(profile, profile.getTimestamp(), IProfile.STATE_PROP_SHARED_INSTALL, IProfile.STATE_SHARED_INSTALL_VALUE_INITIAL);
+					internalSetProfileStateProperty(profile, profile.getTimestamp(), SIMPLE_PROFILE_REGISTRY_INTERNAL + getBaseTimestamp(profile.getProfileId()), getBaseTimestamp(id));
+				}
+			}
+		}
 		return profile;
 	}
 
+	private boolean ignoreExistingProfile(IProfile profile) {
+		if (!Boolean.TRUE.toString().equalsIgnoreCase(System.getProperty(ECLIPSE_IGNORE_USER_CONFIGURATION)))
+			return false;
+
+		String baseTimestamp = getBaseTimestamp(profile.getProfileId());
+		if (baseTimestamp == null)
+			return false;
+
+		if (internalGetProfileStateProperties(profile, SIMPLE_PROFILE_REGISTRY_INTERNAL + baseTimestamp, false).size() != 0)
+			return false;
+
+		return true;
+	}
+
+	private String getBaseTimestamp(String id) {
+		IProvisioningAgent installer = (IProvisioningAgent) agent.getService(IProvisioningAgent.SHARED_BASE_AGENT);
+		if (installer == null)
+			return null;
+		IProfileRegistry registry = (IProfileRegistry) installer.getService(IProfileRegistry.SERVICE_NAME);
+		long[] revisions = registry.listProfileTimestamps(id);
+		if (revisions.length >= 1) {
+			return Long.toString(revisions[revisions.length - 1]);
+		}
+		return null;
+	}
+
 	private Profile createSurrogateProfile(String id) {
 		if (surrogateProfileHandler == null)
 			return null;
@@ -294,7 +341,7 @@ public class SimpleProfileRegistry implements IProfileRegistry, IAgentService {
 
 	public synchronized void updateProfile(Profile profile) {
 		String id = profile.getProfileId();
-		Profile current = internalGetProfile(id);
+		Profile current = getProfileMap().get(id);
 		if (current == null)
 			throw new IllegalArgumentException(NLS.bind(Messages.profile_does_not_exist, id));
 
@@ -730,7 +777,7 @@ public class SimpleProfileRegistry implements IProfileRegistry, IAgentService {
 	}
 
 	public synchronized boolean isCurrent(IProfile profile) {
-		Profile internalProfile = internalGetProfile(profile.getProfileId());
+		Profile internalProfile = getProfileMap().get(profile.getProfileId());
 		if (internalProfile == null)
 			throw new IllegalArgumentException(NLS.bind(Messages.profile_not_registered, profile.getProfileId()));
 
@@ -833,10 +880,9 @@ public class SimpleProfileRegistry implements IProfileRegistry, IAgentService {
 	}
 
 	public synchronized void unlockProfile(IProfile profile) {
-		Profile internalProfile = internalGetProfile(profile.getProfileId());
-		if (internalProfile == null)
+		if (profile == null)
 			throw new IllegalArgumentException(NLS.bind(Messages.profile_not_registered, profile.getProfileId()));
-		internalUnlockProfile(internalProfile);
+		internalUnlockProfile(profile);
 	}
 
 	private void internalUnlockProfile(IProfile profile) {
@@ -897,6 +943,8 @@ public class SimpleProfileRegistry implements IProfileRegistry, IAgentService {
 
 		// return true if the cached timestamp is the same as the one on disk
 		boolean isCurrent() {
+			if (!file.exists())
+				return true;
 			return file.lastModified() == timestamp;
 		}
 
@@ -936,8 +984,10 @@ public class SimpleProfileRegistry implements IProfileRegistry, IAgentService {
 
 		File file = new File(profileDirectory, PROFILE_PROPERTIES_FILE);
 		Properties properties = new Properties();
-		if (!file.exists())
+		if (!file.exists()) {
+			lastAccessedProperties = new ProfileStateProperties(id, file, properties);
 			return properties;
+		}
 		InputStream input = null;
 		try {
 			input = new BufferedInputStream(new FileInputStream(file));
@@ -1032,22 +1082,30 @@ public class SimpleProfileRegistry implements IProfileRegistry, IAgentService {
 	public IStatus setProfileStateProperties(String id, long timestamp, Map<String, String> propertiesToAdd) {
 		if (id == null || propertiesToAdd == null)
 			throw new NullPointerException();
-		IStatus result = validateState(id, timestamp);
+
+		Profile internalProfile = internalGetProfile(id);
+		return internalSetProfileStateProperties(internalProfile, timestamp, propertiesToAdd);
+	}
+
+	private IStatus internalSetProfileStateProperties(IProfile profile, long timestamp, Map<String, String> propertiesToAdd) {
+		IStatus result = validateState(profile.getProfileId(), timestamp);
 		if (!result.isOK())
 			return result;
-		Profile internalProfile = internalGetProfile(id);
-		lockProfile(internalProfile);
+
+		if (!internalLockProfile(profile))
+			throw new IllegalStateException(Messages.SimpleProfileRegistry_Profile_in_use);
+
 		try {
-			Properties properties = readStateProperties(id);
+			Properties properties = readStateProperties(profile.getProfileId());
 			for (Map.Entry<String, String> entry : propertiesToAdd.entrySet()) {
 				// property key format is timestamp.key
 				properties.put(timestamp + "." + entry.getKey(), entry.getValue()); //$NON-NLS-1$
 			}
-			writeStateProperties(id, properties);
+			writeStateProperties(profile.getProfileId(), properties);
 		} catch (ProvisionException e) {
 			return e.getStatus();
 		} finally {
-			unlockProfile(internalProfile);
+			internalUnlockProfile(profile);
 		}
 		return Status.OK_STATUS;
 	}
@@ -1056,27 +1114,36 @@ public class SimpleProfileRegistry implements IProfileRegistry, IAgentService {
 	 * @see org.eclipse.equinox.p2.engine.IProfileRegistry#setProfileStateProperty(java.lang.String, long, java.lang.String, java.lang.String)
 	 */
 	public IStatus setProfileStateProperty(String id, long timestamp, String key, String value) {
-		if (id == null || key == null || value == null)
+		if (id == null)
+			throw new NullPointerException();
+		return internalSetProfileStateProperty(internalGetProfile(id), timestamp, key, value);
+	}
+
+	private IStatus internalSetProfileStateProperty(IProfile profile, long timestamp, String key, String value) {
+		if (key == null || value == null)
 			throw new NullPointerException();
 		Map<String, String> properties = new HashMap<String, String>();
 		properties.put(key, value);
-		return setProfileStateProperties(id, timestamp, properties);
+
+		return internalSetProfileStateProperties(profile, timestamp, properties);
 	}
 
-	/* (non-Javadoc)
-	 * @see org.eclipse.equinox.p2.engine.IProfileRegistry#getProfileStateProperties(java.lang.String, long)
-	 */
 	public Map<String, String> getProfileStateProperties(String id, long timestamp) {
 		if (id == null)
 			throw new NullPointerException();
+		return internalGetProfileStateProperties(internalGetProfile(id), timestamp, true);
+	}
 
+	private Map<String, String> internalGetProfileStateProperties(IProfile profile, long timestamp, boolean lock) {
 		Map<String, String> result = new HashMap<String, String>();
 		String timestampString = String.valueOf(timestamp);
 		int keyOffset = timestampString.length() + 1;
-		Profile internalProfile = internalGetProfile(id);
-		lockProfile(internalProfile);
+		lock = lock || lastAccessedProperties == null;
+		if (lock)
+			if (!internalLockProfile(profile))
+				throw new IllegalStateException(Messages.SimpleProfileRegistry_Profile_in_use);
 		try {
-			Properties properties = readStateProperties(id);
+			Properties properties = readStateProperties(profile.getProfileId());
 			Iterator<Object> keys = properties.keySet().iterator();
 			while (keys.hasNext()) {
 				String key = (String) keys.next();
@@ -1086,7 +1153,8 @@ public class SimpleProfileRegistry implements IProfileRegistry, IAgentService {
 		} catch (ProvisionException e) {
 			LogHelper.log(e);
 		} finally {
-			unlockProfile(internalProfile);
+			if (lock)
+				internalUnlockProfile(profile);
 		}
 		return result;
 	}
@@ -1098,11 +1166,18 @@ public class SimpleProfileRegistry implements IProfileRegistry, IAgentService {
 		if (id == null || userKey == null)
 			throw new NullPointerException();
 
-		Map<String, String> result = new HashMap<String, String>();
 		Profile internalProfile = internalGetProfile(id);
-		lockProfile(internalProfile);
+		return internalGetProfileStateProperties(internalProfile, userKey, true);
+	}
+
+	private Map<String, String> internalGetProfileStateProperties(IProfile profile, String userKey, boolean lock) {
+		Map<String, String> result = new HashMap<String, String>();
+		lock = lock || lastAccessedProperties == null;
+		if (lock)
+			if (!internalLockProfile(profile))
+				throw new IllegalStateException(Messages.SimpleProfileRegistry_Profile_in_use);
 		try {
-			Properties properties = readStateProperties(id);
+			Properties properties = readStateProperties(profile.getProfileId());
 			Iterator<Object> keys = properties.keySet().iterator();
 			while (keys.hasNext()) {
 				// property key format is timestamp.key
@@ -1115,7 +1190,8 @@ public class SimpleProfileRegistry implements IProfileRegistry, IAgentService {
 		} catch (ProvisionException e) {
 			LogHelper.log(e);
 		} finally {
-			unlockProfile(internalProfile);
+			if (lock)
+				internalUnlockProfile(profile);
 		}
 		return result;
 	}
@@ -1131,7 +1207,9 @@ public class SimpleProfileRegistry implements IProfileRegistry, IAgentService {
 			return Status.OK_STATUS;
 
 		Profile internalProfile = internalGetProfile(id);
-		lockProfile(internalProfile);
+		if (!internalLockProfile(internalProfile))
+			throw new IllegalStateException(Messages.SimpleProfileRegistry_Profile_in_use);
+
 		try {
 			Properties properties = readStateProperties(id);
 			String timestampString = String.valueOf(timestamp);
@@ -1154,7 +1232,7 @@ public class SimpleProfileRegistry implements IProfileRegistry, IAgentService {
 		} catch (ProvisionException e) {
 			return e.getStatus();
 		} finally {
-			unlockProfile(internalProfile);
+			internalUnlockProfile(internalProfile);
 		}
 		return Status.OK_STATUS;
 	}
diff --git a/bundles/org.eclipse.equinox.p2.engine/src/org/eclipse/equinox/p2/engine/IProfile.java b/bundles/org.eclipse.equinox.p2.engine/src/org/eclipse/equinox/p2/engine/IProfile.java
index 1f8de7645..7bd0060c2 100644
--- a/bundles/org.eclipse.equinox.p2.engine/src/org/eclipse/equinox/p2/engine/IProfile.java
+++ b/bundles/org.eclipse.equinox.p2.engine/src/org/eclipse/equinox/p2/engine/IProfile.java
@@ -7,6 +7,7 @@
  * 
  *  Contributors:
  *     IBM Corporation - initial API and implementation
+ *     Ericsson AB - ongoing development
  *******************************************************************************/
 package org.eclipse.equinox.p2.engine;
 
@@ -146,6 +147,29 @@ public interface IProfile extends IQueryable<IInstallableUnit> {
 	public static final String STATE_PROP_TAG = "org.eclipse.equinox.p2.state.tag"; //$NON-NLS-1$
 
 	/**
+	 * Profile state metadata property key used to represent the state of the user profile when running in shared install.
+	 * The value for this property could be:  {@value #STATE_PROP_INITIAL}, {@value #STATE_SHARED_INSTALL_VALUE_BEFOREFLUSH}, or {@value #STATE_SHARED_INSTALL_VALUE_NEW}
+	 * @since 2.3
+	 */
+	public static final String STATE_PROP_SHARED_INSTALL = "org.eclipse.equinox.p2.state.shared"; //$NON-NLS-1$
+
+	/**
+	 * Value to represent a user profile the first time it is created.
+	 * @since 2.3
+	 */
+	public static final String STATE_SHARED_INSTALL_VALUE_INITIAL = "initial"; //$NON-NLS-1$
+	/**
+	 * Value to represent a user profile before it is being flushed because the base had changed.
+	 * @since 2.3
+	 */
+	public static final String STATE_SHARED_INSTALL_VALUE_BEFOREFLUSH = "beforeFlush"; //$NON-NLS-1$
+	/**
+	 * Value to represent the new user profile created once the base profile has been flushed.
+	 * @since 2.3
+	 */
+	public static final String STATE_SHARED_INSTALL_VALUE_NEW = "new"; //$NON-NLS-1$
+
+	/**
 	 * Profile property constant for additional parameters of the downloading stats(e.g., package=jee&os=linux).
 	 * @since 2.2 
 	 */
diff --git a/bundles/org.eclipse.equinox.p2.engine/src/org/eclipse/equinox/p2/engine/IProfileRegistry.java b/bundles/org.eclipse.equinox.p2.engine/src/org/eclipse/equinox/p2/engine/IProfileRegistry.java
index 381a61e20..b2490c894 100644
--- a/bundles/org.eclipse.equinox.p2.engine/src/org/eclipse/equinox/p2/engine/IProfileRegistry.java
+++ b/bundles/org.eclipse.equinox.p2.engine/src/org/eclipse/equinox/p2/engine/IProfileRegistry.java
@@ -1,5 +1,5 @@
 /*******************************************************************************
- * Copyright (c) 2007, 2011 IBM Corporation and others.
+ * Copyright (c) 2007, 2013 IBM Corporation and others.
  * All rights reserved. This program and the accompanying materials
  * are made available under the terms of the Eclipse Public License v1.0
  * which accompanies this distribution, and is available at
@@ -7,6 +7,7 @@
  *
  * Contributors:
  *     IBM Corporation - initial API and implementation
+ *     Ericsson AB - ongoing development
  *******************************************************************************/
 package org.eclipse.equinox.p2.engine;
 
@@ -37,6 +38,8 @@ public interface IProfileRegistry {
 	 */
 	public static final String SERVICE_NAME = IProfileRegistry.class.getName();
 
+	public static final String SERVICE_SHARED_INSTALL_NEW_TIMESTAMP = IProfileRegistry.class.getName() + '_' + "NEW_SELF_TIMESTAMP"; //$NON-NLS-1$
+
 	/**
 	 * Return the profile in the registry that has the given id. If it does not exist, 
 	 * then return <code>null</code>.
diff --git a/bundles/org.eclipse.equinox.p2.reconciler.dropins/src/org/eclipse/equinox/internal/p2/reconciler/dropins/Activator.java b/bundles/org.eclipse.equinox.p2.reconciler.dropins/src/org/eclipse/equinox/internal/p2/reconciler/dropins/Activator.java
index d8da4f56a..800871953 100644
--- a/bundles/org.eclipse.equinox.p2.reconciler.dropins/src/org/eclipse/equinox/internal/p2/reconciler/dropins/Activator.java
+++ b/bundles/org.eclipse.equinox.p2.reconciler.dropins/src/org/eclipse/equinox/internal/p2/reconciler/dropins/Activator.java
@@ -227,6 +227,13 @@ public class Activator implements BundleActivator {
 			trace("Performing reconciliation."); //$NON-NLS-1$
 			return false;
 		}
+		// master configuration changed. Reconcile.
+		if (Boolean.TRUE.toString().equalsIgnoreCase(System.getProperty(ProfileSynchronizer.PROP_IGNORE_USER_CONFIGURATION))) {
+			Activator.trace("Master profile changed."); //$NON-NLS-1$
+			Activator.trace("Performing reconciliation."); //$NON-NLS-1$
+			return false;
+		}
+
 		// read timestamps
 		Properties timestamps = readTimestamps();
 		if (timestamps.isEmpty()) {
diff --git a/bundles/org.eclipse.equinox.p2.reconciler.dropins/src/org/eclipse/equinox/internal/p2/reconciler/dropins/ProfileSynchronizer.java b/bundles/org.eclipse.equinox.p2.reconciler.dropins/src/org/eclipse/equinox/internal/p2/reconciler/dropins/ProfileSynchronizer.java
index 337d41a86..cf3feb315 100644
--- a/bundles/org.eclipse.equinox.p2.reconciler.dropins/src/org/eclipse/equinox/internal/p2/reconciler/dropins/ProfileSynchronizer.java
+++ b/bundles/org.eclipse.equinox.p2.reconciler.dropins/src/org/eclipse/equinox/internal/p2/reconciler/dropins/ProfileSynchronizer.java
@@ -1,5 +1,5 @@
 /*******************************************************************************
- * Copyright (c) 2007, 2012 IBM Corporation and others. All rights reserved.
+ * Copyright (c) 2007, 2013 IBM Corporation and others. All rights reserved.
  * This program and the accompanying materials are made available under the
  * terms of the Eclipse Public License v1.0 which accompanies this distribution,
  * and is available at http://www.eclipse.org/legal/epl-v10.html
@@ -7,11 +7,10 @@
  * Contributors: 
  * IBM Corporation - initial implementation and ideas
  *     Sonatype, Inc. - ongoing development
+ *     RedHat, Inc. - Bug 397216
  ******************************************************************************/
 package org.eclipse.equinox.internal.p2.reconciler.dropins;
 
-import org.eclipse.equinox.p2.metadata.IRequirement;
-
 import java.io.*;
 import java.net.*;
 import java.util.*;
@@ -56,6 +55,9 @@ public class ProfileSynchronizer {
 	private static final String CACHE_EXTENSIONS = "org.eclipse.equinox.p2.cache.extensions"; //$NON-NLS-1$
 	private static final String PIPE = "|"; //$NON-NLS-1$
 	private static final String EXPLANATION = "org.eclipse.equinox.p2.director.explain"; //$NON-NLS-1$
+
+	static final String PROP_IGNORE_USER_CONFIGURATION = "eclipse.ignoreUserConfiguration"; //$NON-NLS-1$
+
 	final IProfile profile;
 
 	final Map<String, IMetadataRepository> repositoryMap;
@@ -396,6 +398,12 @@ public class ProfileSynchronizer {
 	 * Read the values of the stored timestamps that we use for caching.
 	 */
 	private void readTimestamps() {
+		if (Boolean.TRUE.toString().equalsIgnoreCase(System.getProperty(PROP_IGNORE_USER_CONFIGURATION))) {
+			timestamps = new HashMap<String, String>();
+			Activator.trace("Master profile changed."); //$NON-NLS-1$
+			Activator.trace("Performing reconciliation."); //$NON-NLS-1$
+			return;
+		}
 		File file = Activator.getContext().getDataFile(TIMESTAMPS_FILE_PREFIX + profile.getProfileId().hashCode());
 		try {
 			InputStream is = new BufferedInputStream(new FileInputStream(file));
diff --git a/bundles/org.eclipse.equinox.p2.tests/src/org/eclipse/equinox/p2/tests/simpleconfigurator/SimpleConfiguratorTest.java b/bundles/org.eclipse.equinox.p2.tests/src/org/eclipse/equinox/p2/tests/simpleconfigurator/SimpleConfiguratorTest.java
new file mode 100644
index 000000000..0d964ac49
--- /dev/null
+++ b/bundles/org.eclipse.equinox.p2.tests/src/org/eclipse/equinox/p2/tests/simpleconfigurator/SimpleConfiguratorTest.java
@@ -0,0 +1,106 @@
+/*******************************************************************************
+ * Copyright (c) 2012 Red Hat, Inc. and others. All rights reserved. This
+ * program and the accompanying materials are made available under the terms of
+ * the Eclipse Public License v1.0 which accompanies this distribution, and is
+ * available at http://www.eclipse.org/legal/epl-v10.html
+ * 
+ * Contributors: Red Hat, Inc. - initial API and implementation
+ ******************************************************************************/
+package org.eclipse.equinox.p2.tests.simpleconfigurator;
+
+import java.io.*;
+import java.net.MalformedURLException;
+import java.net.URL;
+import java.util.Properties;
+import org.eclipse.equinox.internal.simpleconfigurator.SimpleConfiguratorImpl;
+import org.eclipse.equinox.p2.tests.AbstractProvisioningTest;
+
+public class SimpleConfiguratorTest extends AbstractProvisioningTest {
+
+	private URL relativeURL;
+	private File userConfiguration;
+	private File masterConfguration;
+	private URL[] sharedConfiguration = new URL[2];
+	private URL[] localConfiguration = new URL[1];
+	private SimpleConfiguratorImpl configurator;
+
+	public void setUp() throws Exception {
+		relativeURL = new URL("file://bundles.info");
+		userConfiguration = getTestData("userConfiguration", "testData/simpleconfigurator/user");
+		sharedConfiguration[0] = userConfiguration.toURL();
+		masterConfguration = getTestData("userConfiguration", "testData/simpleconfigurator/master");
+		sharedConfiguration[1] = masterConfguration.toURL();
+		localConfiguration[0] = sharedConfiguration[1];
+		configurator = getSimpleConfigurator();
+	}
+
+	private SimpleConfiguratorImpl getSimpleConfigurator() {
+		return new SimpleConfiguratorImpl(null, null);
+	}
+
+	private void storeTimestamp(long timestamp) throws IOException {
+		File f = new File(userConfiguration.getParent(), SimpleConfiguratorImpl.BASE_TIMESTAMP_FILE_BUNDLESINFO);
+		Properties p = new Properties();
+		p.put(SimpleConfiguratorImpl.KEY_BUNDLESINFO_TIMESTAMP, "" + timestamp);
+		p.store(new FileWriter(f), "");
+	}
+
+	@Override
+	protected void tearDown() throws Exception {
+		System.setProperty(SimpleConfiguratorImpl.PROP_IGNORE_USER_CONFIGURATION, "false");
+		File f = new File(userConfiguration.getParent(), SimpleConfiguratorImpl.BASE_TIMESTAMP_FILE_BUNDLESINFO);
+		if (f.exists()) {
+			f.delete();
+		}
+		super.tearDown();
+	}
+
+	private void assertIsPropertySet(boolean set) {
+		assertEquals(set, Boolean.TRUE.toString().equalsIgnoreCase(System.getProperty(SimpleConfiguratorImpl.PROP_IGNORE_USER_CONFIGURATION)));
+	}
+
+	public void testSimpleConfiguration() throws MalformedURLException {
+		assertEquals(localConfiguration[0], configurator.chooseConfigurationURL(relativeURL, localConfiguration));
+		assertIsPropertySet(false);
+	}
+
+	public void testNotExistingConfigiration() throws MalformedURLException {
+		assertNull(configurator.chooseConfigurationURL(relativeURL, new URL[] {new File(".", "notexisting").toURL()}));
+		assertIsPropertySet(false);
+	}
+
+	public void testSharedConfigurationUserNotExisting() throws MalformedURLException {
+		sharedConfiguration[0] = new File(".", "notexisting").toURL();
+		assertEquals(sharedConfiguration[1], configurator.chooseConfigurationURL(relativeURL, sharedConfiguration));
+		assertIsPropertySet(false);
+	}
+
+	// no timestamp -> pick user
+	public void testSharedConfigurationNoTimestamp() throws MalformedURLException {
+		assertEquals(sharedConfiguration[0], configurator.chooseConfigurationURL(relativeURL, sharedConfiguration));
+		assertIsPropertySet(false);
+	}
+
+	//master modified -> pick master
+	public void testSharedConfigurationMasterModified() throws IOException {
+		storeTimestamp(1000);
+		assertEquals(sharedConfiguration[1], configurator.chooseConfigurationURL(relativeURL, sharedConfiguration));
+		assertIsPropertySet(true);
+	}
+
+	//master not modified -> pick user
+	public void testSharedConfigurationMasterUnmodified() throws IOException {
+		storeTimestamp(new File(masterConfguration, relativeURL.getFile()).lastModified());
+		assertEquals(sharedConfiguration[0], configurator.chooseConfigurationURL(relativeURL, sharedConfiguration));
+		assertIsPropertySet(false);
+	}
+
+	//master not modified, but property present -> pick master
+	public void testSharedConfigurationMasterUnmodifiedPropertySet() throws IOException {
+		System.setProperty(SimpleConfiguratorImpl.PROP_IGNORE_USER_CONFIGURATION, "true");
+		storeTimestamp(new File(masterConfguration, relativeURL.getFile()).lastModified());
+		assertEquals(sharedConfiguration[1], configurator.chooseConfigurationURL(relativeURL, sharedConfiguration));
+		assertIsPropertySet(true);
+	}
+
+}
diff --git a/bundles/org.eclipse.equinox.p2.tests/src/org/eclipse/equinox/p2/tests/simpleconfigurator/SimpleConfiguratorTests.java b/bundles/org.eclipse.equinox.p2.tests/src/org/eclipse/equinox/p2/tests/simpleconfigurator/SimpleConfiguratorTests.java
index a3b448fa5..454f30d8c 100644
--- a/bundles/org.eclipse.equinox.p2.tests/src/org/eclipse/equinox/p2/tests/simpleconfigurator/SimpleConfiguratorTests.java
+++ b/bundles/org.eclipse.equinox.p2.tests/src/org/eclipse/equinox/p2/tests/simpleconfigurator/SimpleConfiguratorTests.java
@@ -16,6 +16,7 @@ public class SimpleConfiguratorTests {
 	public static Test suite() {
 		TestSuite suite = new TestSuite("Tests for org.eclipse.equinox.simpleconfigurator");
 		//$JUnit-BEGIN$
+		suite.addTestSuite(SimpleConfiguratorTest.class);
 		suite.addTestSuite(SimpleConfiguratorUtilsTest.class);
 		suite.addTestSuite(BundlesTxtTest.class);
 		suite.addTestSuite(NonExclusiveMode.class);
diff --git a/bundles/org.eclipse.equinox.p2.tests/testData/simpleconfigurator/master/bundles.info b/bundles/org.eclipse.equinox.p2.tests/testData/simpleconfigurator/master/bundles.info
new file mode 100644
index 000000000..e69de29bb
--- /dev/null
+++ b/bundles/org.eclipse.equinox.p2.tests/testData/simpleconfigurator/master/bundles.info
diff --git a/bundles/org.eclipse.equinox.p2.tests/testData/simpleconfigurator/user/bundles.info b/bundles/org.eclipse.equinox.p2.tests/testData/simpleconfigurator/user/bundles.info
new file mode 100644
index 000000000..e69de29bb
--- /dev/null
+++ b/bundles/org.eclipse.equinox.p2.tests/testData/simpleconfigurator/user/bundles.info
diff --git a/bundles/org.eclipse.equinox.p2.ui.sdk.scheduler/src/org/eclipse/equinox/internal/p2/ui/sdk/scheduler/AutomaticUpdateScheduler.java b/bundles/org.eclipse.equinox.p2.ui.sdk.scheduler/src/org/eclipse/equinox/internal/p2/ui/sdk/scheduler/AutomaticUpdateScheduler.java
index 785a01845..06186bb8b 100644
--- a/bundles/org.eclipse.equinox.p2.ui.sdk.scheduler/src/org/eclipse/equinox/internal/p2/ui/sdk/scheduler/AutomaticUpdateScheduler.java
+++ b/bundles/org.eclipse.equinox.p2.ui.sdk.scheduler/src/org/eclipse/equinox/internal/p2/ui/sdk/scheduler/AutomaticUpdateScheduler.java
@@ -1,5 +1,5 @@
 /*******************************************************************************
- * Copyright (c) 2008, 2011 IBM Corporation and others.
+ * Copyright (c) 2008, 2013 IBM Corporation and others.
  * All rights reserved. This program and the accompanying materials
  * are made available under the terms of the Eclipse Public License v1.0
  * which accompanies this distribution, and is available at
@@ -7,6 +7,7 @@
  *
  * Contributors:
  *     IBM Corporation - initial API and implementation
+ *     Ericsson AB - ongoing development
  *******************************************************************************/
 package org.eclipse.equinox.internal.p2.ui.sdk.scheduler;
 
@@ -22,8 +23,11 @@ import org.eclipse.equinox.p2.engine.IProfileRegistry;
 import org.eclipse.equinox.p2.engine.query.IUProfilePropertyQuery;
 import org.eclipse.equinox.p2.metadata.IInstallableUnit;
 import org.eclipse.equinox.p2.query.IQuery;
+import org.eclipse.jface.dialogs.MessageDialog;
 import org.eclipse.jface.preference.IPreferenceStore;
-import org.eclipse.ui.IStartup;
+import org.eclipse.swt.widgets.Display;
+import org.eclipse.swt.widgets.Shell;
+import org.eclipse.ui.*;
 import org.eclipse.ui.statushandlers.StatusManager;
 
 /**
@@ -78,10 +82,46 @@ public class AutomaticUpdateScheduler implements IStartup {
 	}
 
 	public void earlyStartup() {
+		if (baseChanged())
+			return;
 		garbageCollect();
 		scheduleUpdate();
 	}
 
+	Shell getWorkbenchWindowShell() {
+		IWorkbenchWindow activeWindow = PlatformUI.getWorkbench().getActiveWorkbenchWindow();
+		return activeWindow != null ? activeWindow.getShell() : null;
+
+	}
+
+	private boolean baseChanged() {
+		IProvisioningAgent agent = (IProvisioningAgent) ServiceHelper.getService(AutomaticUpdatePlugin.getContext(), IProvisioningAgent.SERVICE_NAME);
+		IProfileRegistry registry = (IProfileRegistry) agent.getService(IProfileRegistry.SERVICE_NAME);
+		//Access the running profile to force its reinitialization if it has not been done.
+		registry.getProfile(IProfileRegistry.SELF);
+		String resetState = (String) agent.getService(IProfileRegistry.SERVICE_SHARED_INSTALL_NEW_TIMESTAMP);
+		if (resetState == null)
+			return false;
+
+		final String PREF_MIGRATION_DIALOG_SHOWN = "migrationDialogShown"; //$NON-NLS-1$
+
+		//Have we already shown the migration dialog
+		if (AutomaticUpdatePlugin.getDefault().getPreferenceStore().getString(PREF_MIGRATION_DIALOG_SHOWN) == resetState)
+			return false;
+
+		//Remember that we are showing the migration dialog
+		AutomaticUpdatePlugin.getDefault().getPreferenceStore().setValue(PREF_MIGRATION_DIALOG_SHOWN, resetState);
+		AutomaticUpdatePlugin.getDefault().savePreferences();
+
+		Display d = Display.getDefault();
+		d.asyncExec(new Runnable() {
+			public void run() {
+				MessageDialog.openWarning(getWorkbenchWindowShell(), "Installation modified", "An upgrade of the eclipse installation you are using has been performed. The plugins you had installed have been uninstalled."); //$NON-NLS-1$ //$NON-NLS-2$
+			}
+		});
+		return true;
+	}
+
 	/**
 	 * Invokes the garbage collector to discard unused plugins, if specified by a 
 	 * corresponding preference.
diff --git a/bundles/org.eclipse.equinox.p2.ui/src/org/eclipse/equinox/p2/ui/RepositoryManipulationPage.java b/bundles/org.eclipse.equinox.p2.ui/src/org/eclipse/equinox/p2/ui/RepositoryManipulationPage.java
index 73b63c7a8..914f56c2d 100644
--- a/bundles/org.eclipse.equinox.p2.ui/src/org/eclipse/equinox/p2/ui/RepositoryManipulationPage.java
+++ b/bundles/org.eclipse.equinox.p2.ui/src/org/eclipse/equinox/p2/ui/RepositoryManipulationPage.java
@@ -1,5 +1,5 @@
 /*******************************************************************************
- *  Copyright (c) 2007, 2012 IBM Corporation and others.
+ *  Copyright (c) 2007, 2013 IBM Corporation and others.
  *  All rights reserved. This program and the accompanying materials
  *  are made available under the terms of the Eclipse Public License v1.0
  *  which accompanies this distribution, and is available at
@@ -7,6 +7,7 @@
  * 
  *  Contributors:
  *     IBM Corporation - initial API and implementation
+ *     Ericsson AB (Pascal Rapicault) - bug 398539
  *******************************************************************************/
 package org.eclipse.equinox.p2.ui;
 
@@ -774,7 +775,7 @@ public class RepositoryManipulationPage extends PreferencePage implements IWorkb
 		};
 
 		int retCode = dialog.open();
-		if (retCode == Window.OK) {
+		if (retCode == Window.OK && dialog.getLocation() != null) {
 			selected[0].setNickname(dialog.getName());
 			selected[0].setLocation(dialog.getLocation());
 			if (dialog.getLocation().equals(existingLocation)) {
diff --git a/bundles/org.eclipse.equinox.simpleconfigurator.manipulator/src/org/eclipse/equinox/internal/simpleconfigurator/manipulator/SimpleConfiguratorManipulatorImpl.java b/bundles/org.eclipse.equinox.simpleconfigurator.manipulator/src/org/eclipse/equinox/internal/simpleconfigurator/manipulator/SimpleConfiguratorManipulatorImpl.java
index c6748e918..55e1743dd 100644
--- a/bundles/org.eclipse.equinox.simpleconfigurator.manipulator/src/org/eclipse/equinox/internal/simpleconfigurator/manipulator/SimpleConfiguratorManipulatorImpl.java
+++ b/bundles/org.eclipse.equinox.simpleconfigurator.manipulator/src/org/eclipse/equinox/internal/simpleconfigurator/manipulator/SimpleConfiguratorManipulatorImpl.java
@@ -1,10 +1,13 @@
 /*******************************************************************************
- * Copyright (c) 2007, 2010 IBM Corporation and others. All rights reserved.
+ * Copyright (c) 2007, 2013 IBM Corporation and others. All rights reserved.
  * This program and the accompanying materials are made available under the
  * terms of the Eclipse Public License v1.0 which accompanies this distribution,
  * and is available at http://www.eclipse.org/legal/epl-v10.html
  * 
  * Contributors: IBM Corporation - initial API and implementation
+ * 
+ * Ericsson AB (Pascal Rapicault) - Bug 397216 -[Shared] Better shared
+ * configuration change discovery
  *******************************************************************************/
 package org.eclipse.equinox.internal.simpleconfigurator.manipulator;
 
@@ -42,8 +45,10 @@ public class SimpleConfiguratorManipulatorImpl implements SimpleConfiguratorMani
 
 	public static final String PROP_KEY_EXCLUSIVE_INSTALLATION = "org.eclipse.equinox.simpleconfigurator.exclusiveInstallation"; //$NON-NLS-1$
 	public static final String CONFIG_LIST = "bundles.info"; //$NON-NLS-1$
+	public static final String CONFIG_FOLDER = "configuration"; //$NON-NLS-1$
 	public static final String CONFIGURATOR_FOLDER = "org.eclipse.equinox.simpleconfigurator"; //$NON-NLS-1$
 	public static final String PROP_KEY_CONFIGURL = "org.eclipse.equinox.simpleconfigurator.configUrl"; //$NON-NLS-1$
+	public static final String SHARED_BUNDLES_INFO = CONFIG_FOLDER + File.separatorChar + CONFIGURATOR_FOLDER + File.separatorChar + CONFIG_LIST;
 
 	private Set manipulators = new HashSet();
 
@@ -63,7 +68,7 @@ public class SimpleConfiguratorManipulatorImpl implements SimpleConfiguratorMani
 				if (manipulator.getLauncherData().getLauncher() != null) {
 					baseDir = manipulator.getLauncherData().getLauncher().getParentFile();
 				} else {
-					throw new IllegalStateException("All of fwConfigFile, home, launcher are not set.");
+					throw new IllegalStateException("All of fwConfigFile, home, launcher are not set."); //$NON-NLS-1$
 				}
 			}
 		} else {
@@ -393,6 +398,33 @@ public class SimpleConfiguratorManipulatorImpl implements SimpleConfiguratorMani
 			return;
 		}
 		SimpleConfiguratorManipulatorUtils.writeConfiguration(simpleInfos, outputFile);
+		if (CONFIG_LIST.equals(outputFile.getName()) && isSharedInstallSetup(URIUtil.toFile(installArea), outputFile))
+			rememberSharedBundlesInfoTimestamp(installArea, outputFile.getParentFile());
+	}
+
+	private void rememberSharedBundlesInfoTimestamp(URI installArea, File outputFolder) {
+		if (installArea == null)
+			return;
+
+		File sharedBundlesInfo = new File(URIUtil.append(installArea, SHARED_BUNDLES_INFO));
+		if (!sharedBundlesInfo.exists())
+			return;
+
+		Properties timestampToPersist = new Properties();
+		timestampToPersist.put(SimpleConfiguratorImpl.KEY_BUNDLESINFO_TIMESTAMP, Long.toString(sharedBundlesInfo.lastModified()));
+		OutputStream os = null;
+		try {
+			try {
+				File outputFile = new File(outputFolder, SimpleConfiguratorImpl.BASE_TIMESTAMP_FILE_BUNDLESINFO);
+				os = new BufferedOutputStream(new FileOutputStream(outputFile));
+				timestampToPersist.store(os, "Written by " + this.getClass()); //$NON-NLS-1$
+			} finally {
+				if (os != null)
+					os.close();
+			}
+		} catch (IOException e) {
+			return;
+		}
 	}
 
 	private org.eclipse.equinox.internal.simpleconfigurator.utils.BundleInfo[] convertBundleInfos(BundleInfo[] configuration, URI installArea) {
@@ -402,7 +434,7 @@ public class SimpleConfiguratorManipulatorImpl implements SimpleConfiguratorMani
 			BundleInfo bundleInfo = configuration[i];
 			URI location = bundleInfo.getLocation();
 			if (bundleInfo.getSymbolicName() == null || bundleInfo.getVersion() == null || location == null)
-				throw new IllegalArgumentException("Cannot persist bundleinfo: " + bundleInfo.toString());
+				throw new IllegalArgumentException("Cannot persist bundleinfo: " + bundleInfo.toString()); //$NON-NLS-1$
 			//only need to make a new BundleInfo if we are changing it.
 			if (installArea != null)
 				location = URIUtil.makeRelative(location, installArea);
@@ -492,13 +524,17 @@ public class SimpleConfiguratorManipulatorImpl implements SimpleConfiguratorMani
 		File configFile = getConfigFile(manipulator);
 
 		File installArea = ParserUtils.getOSGiInstallArea(Arrays.asList(manipulator.getLauncherData().getProgramArgs()), manipulator.getConfigData().getProperties(), manipulator.getLauncherData());
-		BundleInfo[] toInstall = null;
-		try {
-			//input stream will be closed for us
-			toInstall = loadConfiguration(new FileInputStream(configFile), installArea.toURI());
-		} catch (FileNotFoundException e) {
-			//no file, just return an empty list
-			toInstall = new BundleInfo[0];
+		BundleInfo[] toInstall = new BundleInfo[0];
+
+		boolean isShared = isSharedInstallSetup(installArea, configFile);
+		if (!isShared || (isShared && !hasBaseChanged(installArea.toURI(), configFile.getParentFile()))) {
+			try {
+				//input stream will be closed for us
+				toInstall = loadConfiguration(new FileInputStream(configFile), installArea.toURI());
+			} catch (FileNotFoundException e) {
+				//no file, just return an empty list
+				toInstall = new BundleInfo[0];
+			}
 		}
 
 		List toUninstall = new LinkedList();
@@ -538,4 +574,43 @@ public class SimpleConfiguratorManipulatorImpl implements SimpleConfiguratorMani
 		if (outputFile.getParentFile().isDirectory())
 			outputFile.getParentFile().delete();
 	}
+
+	private boolean hasBaseChanged(URI installArea, File outputFolder) {
+		String rememberedTimestamp;
+		try {
+			rememberedTimestamp = (String) loadProperties(new File(outputFolder, SimpleConfiguratorImpl.BASE_TIMESTAMP_FILE_BUNDLESINFO)).get(SimpleConfiguratorImpl.KEY_BUNDLESINFO_TIMESTAMP);
+		} catch (IOException e) {
+			return false;
+		}
+		if (rememberedTimestamp == null)
+			return false;
+
+		File sharedBundlesInfo = new File(URIUtil.append(installArea, SHARED_BUNDLES_INFO));
+		if (!sharedBundlesInfo.exists())
+			return true;
+		return !String.valueOf(sharedBundlesInfo.lastModified()).equals(rememberedTimestamp);
+	}
+
+	private boolean isSharedInstallSetup(File installArea, File outputFile) {
+		//An instance is treated as shared if the bundles.info file is not located in the install area.
+		return !new File(installArea, SHARED_BUNDLES_INFO).equals(outputFile);
+	}
+
+	private Properties loadProperties(File inputFile) throws FileNotFoundException, IOException {
+		Properties props = new Properties();
+		InputStream is = null;
+		try {
+			is = new FileInputStream(inputFile);
+			props.load(is);
+		} finally {
+			try {
+				if (is != null)
+					is.close();
+			} catch (IOException e) {
+				//Do nothing
+			}
+			is = null;
+		}
+		return props;
+	}
 }
diff --git a/bundles/org.eclipse.equinox.simpleconfigurator/src/org/eclipse/equinox/internal/simpleconfigurator/SimpleConfiguratorImpl.java b/bundles/org.eclipse.equinox.simpleconfigurator/src/org/eclipse/equinox/internal/simpleconfigurator/SimpleConfiguratorImpl.java
index dbd2aec45..70d3b4c93 100644
--- a/bundles/org.eclipse.equinox.simpleconfigurator/src/org/eclipse/equinox/internal/simpleconfigurator/SimpleConfiguratorImpl.java
+++ b/bundles/org.eclipse.equinox.simpleconfigurator/src/org/eclipse/equinox/internal/simpleconfigurator/SimpleConfiguratorImpl.java
@@ -1,5 +1,5 @@
 /*******************************************************************************
- *  Copyright (c) 2007, 2010 IBM Corporation and others.
+ *  Copyright (c) 2007, 2013 IBM Corporation and others.
  *  All rights reserved. This program and the accompanying materials
  *  are made available under the terms of the Eclipse Public License v1.0
  *  which accompanies this distribution, and is available at
@@ -7,13 +7,14 @@
  * 
  *  Contributors:
  *      IBM Corporation - initial API and implementation
+ *      Ericsson AB (Pascal Rapicault) - Bug 397216 -[Shared] Better shared configuration change discovery 
  *******************************************************************************/
 package org.eclipse.equinox.internal.simpleconfigurator;
 
-import java.io.File;
-import java.io.IOException;
-import java.net.*;
-import java.util.List;
+import java.io.*;
+import java.net.MalformedURLException;
+import java.net.URL;
+import java.util.Properties;
 import org.eclipse.equinox.internal.provisional.configurator.Configurator;
 import org.eclipse.equinox.internal.simpleconfigurator.utils.*;
 import org.osgi.framework.Bundle;
@@ -42,6 +43,12 @@ public class SimpleConfiguratorImpl implements Configurator {
 	private ConfigApplier configApplier;
 	private Bundle bundle;
 
+	//for change detection in the base when running in shared install mode
+	private static final long NO_TIMESTAMP = -1;
+	public static final String BASE_TIMESTAMP_FILE_BUNDLESINFO = ".baseBundlesInfoTimestamp"; //$NON-NLS-1$
+	public static final String KEY_BUNDLESINFO_TIMESTAMP = "bundlesInfoTimestamp";
+	public static final String PROP_IGNORE_USER_CONFIGURATION = "eclipse.ignoreUserConfiguration"; //$NON-NLS-1$
+
 	public SimpleConfiguratorImpl(BundleContext context, Bundle bundle) {
 		this.context = context;
 		this.bundle = bundle;
@@ -80,27 +87,10 @@ public class SimpleConfiguratorImpl implements Configurator {
 			//if it is an relative file URL, then resolve it against the configuration area
 			// TODO Support relative file URLs when not on Equinox
 			URL[] configURL = EquinoxUtils.getConfigAreaURL(context);
-			if (configURL != null) {
-				File userConfig = new File(configURL[0].getFile(), url.getFile());
-				if (configURL.length == 1)
-					return userConfig.exists() ? userConfig.toURL() : null;
-
-				File sharedConfig = new File(configURL[1].getFile(), url.getFile());
-				if (!userConfig.exists())
-					return sharedConfig.exists() ? sharedConfig.toURL() : null;
-
-				if (!sharedConfig.exists())
-					return userConfig.toURL();
-
-				URI base = EquinoxUtils.getInstallLocationURI(context);
-
-				URL sharedConfigURL = sharedConfig.toURL();
-				List sharedBundles = SimpleConfiguratorUtils.readConfiguration(sharedConfigURL, base);
 
-				URL userConfigURL = userConfig.toURL();
-				List userBundles = SimpleConfiguratorUtils.readConfiguration(userConfigURL, base);
-
-				return (userBundles.containsAll(sharedBundles)) ? userConfigURL : sharedConfigURL;
+			URL result = chooseConfigurationURL(url, configURL);
+			if (result != null) {
+				return result;
 			}
 		} catch (MalformedURLException e) {
 			return null;
@@ -116,6 +106,69 @@ public class SimpleConfiguratorImpl implements Configurator {
 		return null;
 	}
 
+	/**
+	 * This method is public for testing purposes only.
+	 * @param relativeURL - a relative URL of the configuration
+	 * @param configURL - an array of parent config URLs to which relativeURL can be appended. 
+	 */
+	public URL chooseConfigurationURL(URL relativeURL, URL[] configURL) throws MalformedURLException {
+		if (configURL != null) {
+			File userConfig = new File(configURL[0].getFile(), relativeURL.getFile());
+			if (configURL.length == 1)
+				return userConfig.exists() ? userConfig.toURL() : null;
+
+			File sharedConfig = new File(configURL[1].getFile(), relativeURL.getFile());
+			if (!userConfig.exists())
+				return sharedConfig.exists() ? sharedConfig.toURL() : null;
+
+			if (!sharedConfig.exists())
+				return userConfig.toURL();
+
+			if (Boolean.TRUE.toString().equals(System.getProperty(PROP_IGNORE_USER_CONFIGURATION)))
+				return sharedConfig.toURL();
+
+			long sharedBundlesInfoTimestamp = getCurrentBundlesInfoBaseTimestamp(sharedConfig);
+			long lastKnownBaseTimestamp = getLastKnownBundlesInfoBaseTimestamp(userConfig.getParentFile());
+
+			if (lastKnownBaseTimestamp == sharedBundlesInfoTimestamp || lastKnownBaseTimestamp == NO_TIMESTAMP) {
+				return userConfig.toURL();
+			} else {
+				System.setProperty(PROP_IGNORE_USER_CONFIGURATION, Boolean.TRUE.toString());
+				return sharedConfig.toURL();
+			}
+		}
+		return null;
+	}
+
+	private long getLastKnownBundlesInfoBaseTimestamp(File configFolder) {
+		File storedSharedTimestamp = new File(configFolder, BASE_TIMESTAMP_FILE_BUNDLESINFO);
+		if (!storedSharedTimestamp.exists())
+			return NO_TIMESTAMP;
+
+		Properties p = new Properties();
+		InputStream is = null;
+		try {
+			try {
+				is = new BufferedInputStream(new FileInputStream(storedSharedTimestamp));
+				p.load(is);
+				if (p.get(KEY_BUNDLESINFO_TIMESTAMP) != null) {
+					return Long.valueOf((String) p.get(KEY_BUNDLESINFO_TIMESTAMP)).longValue();
+				}
+			} finally {
+				is.close();
+			}
+		} catch (IOException e) {
+			return NO_TIMESTAMP;
+		}
+		return NO_TIMESTAMP;
+	}
+
+	private long getCurrentBundlesInfoBaseTimestamp(File sharedBundlesInfo) {
+		if (!sharedBundlesInfo.exists())
+			return NO_TIMESTAMP;
+		return sharedBundlesInfo.lastModified();
+	}
+
 	public void applyConfiguration(URL url) throws IOException {
 		synchronized (configurationLock) {
 			if (Activator.DEBUG)