### Eclipse Workspace Patch 1.0
#P org.eclipse.jdt.core.tests.model
Index: src/org/eclipse/jdt/core/tests/model/ClasspathTests.java
===================================================================
RCS file: /cvsroot/eclipse/org.eclipse.jdt.core.tests.model/src/org/eclipse/jdt/core/tests/model/ClasspathTests.java,v
retrieving revision 1.200
diff -u -r1.200 ClasspathTests.java
--- src/org/eclipse/jdt/core/tests/model/ClasspathTests.java	14 May 2009 10:09:36 -0000	1.200
+++ src/org/eclipse/jdt/core/tests/model/ClasspathTests.java	24 Jun 2009 04:59:56 -0000
@@ -5863,5 +5863,69 @@
 	assertTrue("Inclusion pattern was null", e.getInclusionPatterns() != null);
 	assertTrue("Exclusion pattern was null", e.getExclusionPatterns() != null);
 }
+/**
+ * Test adding jar files with absolute file system path using the following modes and ensure the comparison
+ * with a relative path return true.
+ * 1. Variable Entry
+ * 2. User Library
+ * 3. External Jar file
+ * 
+ * @see "https://bugs.eclipse.org/bugs/show_bug.cgi?id=276373"
+ * @throws Exception
+ */
+public void testBug276373() throws Exception {
+	File libDir = null;
+	try {
+		IJavaProject proj =  this.createJavaProject("P", new String[] {}, "bin");
+		IPath libPath = proj.getResource().getLocation().append("lib");
+		JavaCore.setClasspathVariable("MyVar", libPath, null);
+		libDir = new File(libPath.toPortableString());
+		libDir.mkdirs();
+		IClasspathEntry[] classpath = new IClasspathEntry[3];
+		File libJar = new File(libDir, "variableLib.jar");
+		libJar.createNewFile();
+		classpath[0] = JavaCore.newVariableEntry(new Path("/MyVar/variableLib.jar"), null, null);
+
+		libJar = new File(libDir, "externalLib.jar");
+		libJar.createNewFile();
+		classpath[1] = JavaCore.newLibraryEntry(new Path(libJar.getAbsolutePath()), null, null);
+
+		libJar = new File(libDir, "userLib.jar");
+		libJar.createNewFile();
+		
+		ClasspathContainerInitializer initializer= JavaCore.getClasspathContainerInitializer(JavaCore.USER_LIBRARY_CONTAINER_ID);
+		String libraryName = "TestUserLibrary";
+		IPath containerPath = new Path(JavaCore.USER_LIBRARY_CONTAINER_ID);
+		UserLibraryClasspathContainer containerSuggestion = new UserLibraryClasspathContainer(libraryName);
+		initializer.requestClasspathContainerUpdate(containerPath.append(libraryName), null, containerSuggestion);
+
+		IEclipsePreferences preferences = new InstanceScope().getNode(JavaCore.PLUGIN_ID);
+		String propertyName = JavaModelManager.CP_USERLIBRARY_PREFERENCES_PREFIX+"TestUserLibrary";
+		StringBuffer propertyValue = new StringBuffer("<?xml version=\"1.0\" encoding=\"UTF-8\"?>\r\n<userlibrary systemlibrary=\"false\" version=\"1\">\r\n<archive");
+		propertyValue.append(" path=\"" + libJar.getAbsolutePath());
+		propertyValue.append("\"/>\r\n</userlibrary>\r\n");
+		preferences.put(propertyName, propertyValue.toString());
+		preferences.flush();	
+		
+		classpath[2] = JavaCore.newContainerEntry(containerSuggestion.getPath());
+		proj.setRawClasspath(classpath, null);
+		
+		IResource resource = getWorkspaceRoot().getProject("P").getFile("lib/variableLib.jar");
+		assertTrue(proj.isOnClasspath(resource));
+
+		resource = getWorkspaceRoot().getProject("P").getFile("lib/externalLib.jar");
+		assertTrue(proj.isOnClasspath(resource));
+
+		resource = getWorkspaceRoot().getProject("P").getFile("lib/userLib.jar");
+		assertTrue(proj.isOnClasspath(resource));
+	}
+	finally {
+		if (libDir != null) {
+			org.eclipse.jdt.core.tests.util.Util.delete(libDir);
+		}
+		this.deleteProject("P");
+		JavaCore.removeClasspathVariable("MyVar", null);
+	}		
+}
 
 }
#P org.eclipse.jdt.core
Index: model/org/eclipse/jdt/internal/core/JavaProject.java
===================================================================
RCS file: /cvsroot/eclipse/org.eclipse.jdt.core/model/org/eclipse/jdt/internal/core/JavaProject.java,v
retrieving revision 1.424
diff -u -r1.424 JavaProject.java
--- model/org/eclipse/jdt/internal/core/JavaProject.java	23 Apr 2009 15:32:16 -0000	1.424
+++ model/org/eclipse/jdt/internal/core/JavaProject.java	24 Jun 2009 05:00:00 -0000
@@ -2171,6 +2171,13 @@
 			if (entryPath.equals(exactPath)) { // package fragment roots must match exactly entry pathes (no exclusion there)
 				return true;
 			}
+			// https://bugs.eclipse.org/bugs/show_bug.cgi?id=276373
+			// When a classpath entry is absolute, convert the resource's relative path to a file system path and compare
+			// e.g - /P/lib/variableLib.jar and /home/P/lib/variableLib.jar when compared should return true
+			if (entryPath.isAbsolute()
+					&& entryPath.equals(ResourcesPlugin.getWorkspace().getRoot().getLocation().append(exactPath))) {
+				return true;
+			}
 			if (entryPath.isPrefixOf(path)
 					&& !Util.isExcluded(path, ((ClasspathEntry)entry).fullInclusionPatternChars(), ((ClasspathEntry)entry).fullExclusionPatternChars(), isFolderPath)) {
 				return true;
@@ -2190,6 +2197,11 @@
 					&& !Util.isExcluded(elementPath, ((ClasspathEntry)entry).fullInclusionPatternChars(), ((ClasspathEntry)entry).fullExclusionPatternChars(), isFolderPath))
 				return true;
 		}
+		// https://bugs.eclipse.org/bugs/show_bug.cgi?id=276373
+		if (entryPath.isAbsolute()
+				&& entryPath.equals(ResourcesPlugin.getWorkspace().getRoot().getLocation().append(elementPath))) {
+			return true;
+		}
 		return false;
 	}