diff --git a/core/org.eclipse.cdt.core/META-INF/MANIFEST.MF b/core/org.eclipse.cdt.core/META-INF/MANIFEST.MF
index bad3554ca8a..0badfaba81b 100644
--- a/core/org.eclipse.cdt.core/META-INF/MANIFEST.MF
+++ b/core/org.eclipse.cdt.core/META-INF/MANIFEST.MF
@@ -2,7 +2,7 @@ Manifest-Version: 1.0
 Bundle-ManifestVersion: 2
 Bundle-Name: %pluginName
 Bundle-SymbolicName: org.eclipse.cdt.core; singleton:=true
-Bundle-Version: 5.5.0.qualifier
+Bundle-Version: 5.6.0.qualifier
 Bundle-Activator: org.eclipse.cdt.core.CCorePlugin
 Bundle-Vendor: %providerName
 Bundle-Localization: plugin
diff --git a/core/org.eclipse.cdt.core/model/org/eclipse/cdt/core/settings/model/ICSettingEntry.java b/core/org.eclipse.cdt.core/model/org/eclipse/cdt/core/settings/model/ICSettingEntry.java
index 2dfdc007014..8bffda5eb33 100644
--- a/core/org.eclipse.cdt.core/model/org/eclipse/cdt/core/settings/model/ICSettingEntry.java
+++ b/core/org.eclipse.cdt.core/model/org/eclipse/cdt/core/settings/model/ICSettingEntry.java
@@ -1,12 +1,12 @@
 /*******************************************************************************
- * Copyright (c) 2007, 2010 Intel Corporation and others.
+ * Copyright (c) 2007, 2013 Intel 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:
- * Intel Corporation - Initial API and implementation
+ *     Intel Corporation - Initial API and implementation
  *******************************************************************************/
 package org.eclipse.cdt.core.settings.model;
 
@@ -23,6 +23,12 @@ import org.eclipse.cdt.core.settings.model.util.CDataUtil;
  * entries could be safely pooled by {@link CDataUtil#getPooledEntry(ICSettingEntry)}.
  */
 public interface ICSettingEntry {
+	/**
+	 * A constant known to be zero (0), used to indicate that no flags are set.
+	 * @since 5.6
+	 */
+	int NONE = 0;
+
 	/**
 	 * Flag {@code BUILTIN} indicates settings built in a tool (compiler) itself.
 	 * That kind of settings are not passed as options to a compiler but indexer
@@ -100,5 +106,4 @@ public interface ICSettingEntry {
 	boolean equalsByContents(ICSettingEntry entry);
 
 	int getFlags();
-
 }
diff --git a/core/org.eclipse.cdt.core/model/org/eclipse/cdt/core/settings/model/util/LanguageSettingEntriesSerializer.java b/core/org.eclipse.cdt.core/model/org/eclipse/cdt/core/settings/model/util/LanguageSettingEntriesSerializer.java
index c69b3c5a36d..3787a7dd3fa 100644
--- a/core/org.eclipse.cdt.core/model/org/eclipse/cdt/core/settings/model/util/LanguageSettingEntriesSerializer.java
+++ b/core/org.eclipse.cdt.core/model/org/eclipse/cdt/core/settings/model/util/LanguageSettingEntriesSerializer.java
@@ -1,12 +1,12 @@
 /*******************************************************************************
- * Copyright (c) 2007, 2010 Intel Corporation and others.
+ * Copyright (c) 2007, 2013 Intel 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:
- * Intel Corporation - Initial API and implementation
+ *     Intel Corporation - Initial API and implementation
  *******************************************************************************/
 package org.eclipse.cdt.core.settings.model.util;
 
@@ -45,6 +45,8 @@ public class LanguageSettingEntriesSerializer {
 	public static final String SOURCE_PATH = "sourcePath"; //$NON-NLS-1$
 	public static final String OUTPUT_PATH = "outputPath"; //$NON-NLS-1$
 
+	/** @since 5.6 */
+	public static final String NONE = "NONE"; //$NON-NLS-1$
 	public static final String BUILTIN = "BUILTIN"; //$NON-NLS-1$
 	public static final String READONLY = "READONLY"; //$NON-NLS-1$
 	public static final String LOCAL = "LOCAL"; //$NON-NLS-1$
@@ -225,7 +227,10 @@ public class LanguageSettingEntriesSerializer {
 	}
 
 	public static String composeFlagsString(int flags) {
-		StringBuffer buf = new StringBuffer();
+		if (flags == ICSettingEntry.NONE) {
+			return NONE;
+		}
+		StringBuilder buf = new StringBuilder();
 		if ((flags & ICSettingEntry.BUILTIN) != 0) {
 			buf.append(BUILTIN);
 		}
@@ -272,7 +277,7 @@ public class LanguageSettingEntriesSerializer {
 	 * @since 5.4
 	 */
 	public static int composeFlags(String flagsString) {
-		if (flagsString == null || flagsString.length() == 0)
+		if (flagsString == null || flagsString.isEmpty() || flagsString.equals(NONE))
 			return 0;
 
 		StringTokenizer tokenizer = new StringTokenizer(flagsString, FLAGS_SEPARATOR);
@@ -298,5 +303,4 @@ public class LanguageSettingEntriesSerializer {
 
 		return flags;
 	}
-
 }
diff --git a/core/org.eclipse.cdt.core/pom.xml b/core/org.eclipse.cdt.core/pom.xml
index 8d842b35176..4d076adc086 100644
--- a/core/org.eclipse.cdt.core/pom.xml
+++ b/core/org.eclipse.cdt.core/pom.xml
@@ -11,7 +11,7 @@
     <relativePath>../../pom.xml</relativePath>
   </parent>
 
-  <version>5.5.0-SNAPSHOT</version>
+  <version>5.6.0-SNAPSHOT</version>
   <artifactId>org.eclipse.cdt.core</artifactId>
   <packaging>eclipse-plugin</packaging>
 </project>