diff --git a/core/org.eclipse.cdt.core/ChangeLog b/core/org.eclipse.cdt.core/ChangeLog
index 1c26c7f0dcf..9418cb8ba12 100644
--- a/core/org.eclipse.cdt.core/ChangeLog
+++ b/core/org.eclipse.cdt.core/ChangeLog
@@ -1,3 +1,7 @@
+2004-04-28 Alain Magloire
+
+	NPE in the PathEntry.
+
 2004-04-28 Alain Magloire
 
 	Work in Progress for the PathEntry API
diff --git a/core/org.eclipse.cdt.core/model/org/eclipse/cdt/core/model/ILibraryEntry.java b/core/org.eclipse.cdt.core/model/org/eclipse/cdt/core/model/ILibraryEntry.java
index f2141aeb3aa..9e1b8a2419f 100644
--- a/core/org.eclipse.cdt.core/model/org/eclipse/cdt/core/model/ILibraryEntry.java
+++ b/core/org.eclipse.cdt.core/model/org/eclipse/cdt/core/model/ILibraryEntry.java
@@ -70,4 +70,11 @@ public interface ILibraryEntry extends IPathEntry {
 	 */
 	IPath getBaseReference();
 
+	/**
+	 * Returns the complete path, equivalent to:
+	 *   getBasepath().append(getPath());
+	 * @return
+	 */
+	IPath getFullLibraryPath();
+
 }
diff --git a/core/org.eclipse.cdt.core/model/org/eclipse/cdt/internal/core/model/IncludeEntry.java b/core/org.eclipse.cdt.core/model/org/eclipse/cdt/internal/core/model/IncludeEntry.java
index 90aa8ede636..f488285f9b3 100644
--- a/core/org.eclipse.cdt.core/model/org/eclipse/cdt/internal/core/model/IncludeEntry.java
+++ b/core/org.eclipse.cdt.core/model/org/eclipse/cdt/internal/core/model/IncludeEntry.java
@@ -13,6 +13,8 @@
 package org.eclipse.cdt.internal.core.model;
 
 import org.eclipse.cdt.core.model.IIncludeEntry;
+import org.eclipse.core.resources.IResource;
+import org.eclipse.core.resources.ResourcesPlugin;
 import org.eclipse.core.runtime.IPath;
 
 public class IncludeEntry extends APathEntry implements IIncludeEntry {
@@ -22,7 +24,7 @@ public class IncludeEntry extends APathEntry implements IIncludeEntry {
 	public IncludeEntry(IPath resourcePath, IPath basePath, IPath baseRef, IPath includePath, boolean isSystemInclude,
 			IPath[] exclusionPatterns, boolean isExported) {
 		super(IIncludeEntry.CDT_INCLUDE, basePath, baseRef, resourcePath, exclusionPatterns, isExported);
-		this.includePath = includePath;
+		this.includePath = (includePath == null) ? EMPTY_PATH : includePath;
 		this.isSystemInclude = isSystemInclude;
 	}
 
@@ -80,6 +82,18 @@ public class IncludeEntry extends APathEntry implements IIncludeEntry {
 	 * @see org.eclipse.cdt.core.model.IIncludeEntry#getFullIncludePath()
 	 */
 	public IPath getFullIncludePath() {
-		return basePath.append(includePath);
+		IPath p = (!basePath.isEmpty()) ? basePath.append(includePath) : includePath;
+		if (p.isAbsolute()) {
+			return p;
+		}
+		IResource res = ResourcesPlugin.getWorkspace().getRoot().findMember(p);
+		if (res != null) {
+			IPath location = res.getLocation();
+			if (location != null) {
+				return location;
+			}
+		}
+		return p;
 	}
+
 }
diff --git a/core/org.eclipse.cdt.core/model/org/eclipse/cdt/internal/core/model/IncludeReference.java b/core/org.eclipse.cdt.core/model/org/eclipse/cdt/internal/core/model/IncludeReference.java
index 1e180a557c1..4f3e20870b5 100644
--- a/core/org.eclipse.cdt.core/model/org/eclipse/cdt/internal/core/model/IncludeReference.java
+++ b/core/org.eclipse.cdt.core/model/org/eclipse/cdt/internal/core/model/IncludeReference.java
@@ -16,6 +16,7 @@ import java.util.ArrayList;
 import java.util.Map;
 
 import org.eclipse.cdt.core.model.CModelException;
+import org.eclipse.cdt.core.model.CoreModel;
 import org.eclipse.cdt.core.model.CoreModelUtil;
 import org.eclipse.cdt.core.model.ICElement;
 import org.eclipse.cdt.core.model.ICProject;
@@ -40,7 +41,7 @@ public class IncludeReference extends Openable implements IIncludeReference {
 	 * @param type
 	 */
 	public IncludeReference(ICProject cproject, IIncludeEntry entry) {
-		this(cproject, entry, entry.getIncludePath());
+		this(cproject, entry, entry.getFullIncludePath());
 	}
 
 	public IncludeReference(ICElement celement, IIncludeEntry entry, IPath path) {
@@ -94,7 +95,7 @@ public class IncludeReference extends Openable implements IIncludeReference {
 			if (fPath != null) {
 				file = fPath.toFile();
 			} else if (fIncludeEntry != null) {
-				file = fIncludeEntry.getIncludePath().toFile();
+				file = fIncludeEntry.getFullIncludePath().toFile();
 			}
 			String[] names = null;
 			if (file != null && file.isDirectory()) {
@@ -108,7 +109,7 @@ public class IncludeReference extends Openable implements IIncludeReference {
 					ICElement celement = null;
 					if (child.isDirectory()) {
 						celement = new IncludeReference(this, fIncludeEntry, new Path(child.getAbsolutePath()));
-					} else if (child.isFile()) {
+					} else if (CoreModel.isValidTranslationUnitName(names[i]) && child.isFile()) {
 						celement = new ExternalTranslationUnit(this, path.append(names[i]));
 					}
 					if (celement != null) {
diff --git a/core/org.eclipse.cdt.core/model/org/eclipse/cdt/internal/core/model/LibraryEntry.java b/core/org.eclipse.cdt.core/model/org/eclipse/cdt/internal/core/model/LibraryEntry.java
index f1d02fcd6d7..dfa1d1da017 100644
--- a/core/org.eclipse.cdt.core/model/org/eclipse/cdt/internal/core/model/LibraryEntry.java
+++ b/core/org.eclipse.cdt.core/model/org/eclipse/cdt/internal/core/model/LibraryEntry.java
@@ -13,6 +13,8 @@
 package org.eclipse.cdt.internal.core.model;
 
 import org.eclipse.cdt.core.model.ILibraryEntry;
+import org.eclipse.core.resources.IResource;
+import org.eclipse.core.resources.ResourcesPlugin;
 import org.eclipse.core.runtime.IPath;
 
 public class LibraryEntry extends APathEntry implements ILibraryEntry {
@@ -119,7 +121,20 @@ public class LibraryEntry extends APathEntry implements ILibraryEntry {
 		return super.equals(obj);
 	}
 
-	public IPath getFullLibaryPath() {
-		return basePath.append(getPath());
+	public IPath getFullLibraryPath() {
+		IPath lib = getPath();
+		IPath p = (!basePath.isEmpty()) ? basePath.append(lib) : lib;
+		if (p.isAbsolute()) {
+			return p;
+		}
+		IResource res = ResourcesPlugin.getWorkspace().getRoot().findMember(p);
+		if (res != null) {
+			IPath location = res.getLocation();
+			if (location != null) {
+				return location;
+			}
+		}
+		return p;
+
 	}
 }
diff --git a/core/org.eclipse.cdt.core/model/org/eclipse/cdt/internal/core/model/LibraryReferenceArchive.java b/core/org.eclipse.cdt.core/model/org/eclipse/cdt/internal/core/model/LibraryReferenceArchive.java
index d0e96554470..44451036376 100644
--- a/core/org.eclipse.cdt.core/model/org/eclipse/cdt/internal/core/model/LibraryReferenceArchive.java
+++ b/core/org.eclipse.cdt.core/model/org/eclipse/cdt/internal/core/model/LibraryReferenceArchive.java
@@ -23,7 +23,7 @@ public class LibraryReferenceArchive extends Archive implements ILibraryReferenc
 	ILibraryEntry entry;
 
 	public LibraryReferenceArchive(ICElement parent, ILibraryEntry e, IBinaryArchive ar) {
-		super(parent, e.getPath(), ar);
+		super(parent, e.getFullLibraryPath(), ar);
 		entry = e;
 	}
 
@@ -40,7 +40,7 @@ public class LibraryReferenceArchive extends Archive implements ILibraryReferenc
 	 * @see org.eclipse.cdt.core.model.ICElement#getPath()
 	 */
 	public IPath getPath() {
-		return entry.getPath();
+		return entry.getFullLibraryPath();
 	}
 
 	/* (non-Javadoc)
diff --git a/core/org.eclipse.cdt.core/model/org/eclipse/cdt/internal/core/model/LibraryReferenceShared.java b/core/org.eclipse.cdt.core/model/org/eclipse/cdt/internal/core/model/LibraryReferenceShared.java
index b7df01d1f65..aaed8cce072 100644
--- a/core/org.eclipse.cdt.core/model/org/eclipse/cdt/internal/core/model/LibraryReferenceShared.java
+++ b/core/org.eclipse.cdt.core/model/org/eclipse/cdt/internal/core/model/LibraryReferenceShared.java
@@ -23,7 +23,7 @@ public class LibraryReferenceShared extends Binary implements ILibraryReference
 	ILibraryEntry entry;
 
 	public LibraryReferenceShared(ICElement parent, ILibraryEntry e, IBinaryObject bin) {
-		super(parent, e.getPath(), bin);
+		super(parent, e.getFullLibraryPath(), bin);
 		entry = e;
 	}
 
@@ -60,7 +60,7 @@ public class LibraryReferenceShared extends Binary implements ILibraryReference
 	 * @see org.eclipse.cdt.core.model.ICElement#getPath()
 	 */
 	public IPath getPath() {
-		return entry.getPath();
+		return entry.getFullLibraryPath();
 	}
 
 	/* (non-Javadoc)