Bug 27878 infinite loop?
build N1206 on Win2K, IBM VM 1.3.1 in the big workspace I started up, opened the java perspective and navigated to org.eclipse.core.resources/src. When I clicked to expand the src folder my CPU went to 100% for alone time (forever?). Using ctrl-break I got the attached core dump which indicates that the RenameSupport.create() method appears to be called infinitely. Note that memory use does not seem to be increasing.
org.eclipse.jdt.ui/ui/org/eclipse/jdt/ui/refactoring/RenameSupport.java
* @param unit the <tt>ICompilationUnit</tt> to be renamed.
	 * @param flags flags controlling additional parameters. Valid flags are
	 * <code>UPDATE_REFERENCES</code>, <code>UPDATE_JAVADOC_COMMENTS</code>,
	 * <code>UPDATE_REGULAR_COMMENTS</code> and
	 * <code>UPDATE_STRING_LITERALS</code>, or their bitwise OR, or
	 * <code>NONE</code>.
	 * @return the <tt>RenameSupport</tt>.
	 * @throws CoreException if an unexpected error occured while creating
	 * the <tt>RenameSupport</tt>.
	 */
	public static RenameSupport create(ICompilationUnit unit, int flags) throws CoreException {
		RefactoringSupport.CompilationUnit support= new RefactoringSupport.CompilationUnit(unit);
		RenameCompilationUnitRefactoring refactoring= support.getSpecificRefactoring();
		refactoring.setUpdateReferences(updateReferences(flags));
		refactoring.setUpdateJavaDoc(updateJavadocComments(flags));
		refactoring.setUpdateComments(updateRegularComments(flags));
		refactoring.setUpdateStrings(updateStringLiterals(flags));
		return new RenameSupport(support, unit);
	}
	
	/**
	 * Creates a new rename support for the given <tt>IType</tt>.
	 * 
	 * @param type the <tt>IType</tt> to be renamed.
	 * @param flags flags controlling additional parameters. Valid flags are
	 * <code>UPDATE_REFERENCES</code>, <code>UPDATE_JAVADOC_COMMENTS</code>,
	 * <code>UPDATE_REGULAR_COMMENTS</code> and
	 * <code>UPDATE_STRING_LITERALS</code>, or their bitwise OR, or
	 * <code>NONE</code>.
	 * @return the <tt>RenameSupport</tt>.