Bug 150609 [Properties dialog][EFS] File properties for custom filesystem not shown
While implementing a custom filesystem, we came across the following problem: the properties 'last modified', 'location' and 'size' receive the value '<resource does not exist>'. The problem is due to the use of IResource#getLocation() in ResourcePropertySource and FilePropertySource which returns null in case of resources that are not stored on the default local filesystem. IResource#getLocationURI() should be used instead. In fact, this already happens in IDEResourceInfoUtils, which contains static versions of the same property retrieval methods implemented in ResourcePropertySource and FilePropertySource.
bundles/org.eclipse.ui.ide/src/org/eclipse/ui/views/properties/FilePropertySource.java
public FilePropertySource(IFile file) {
        super(file);
    }
    /**
     * Get a PropertyDescriptor that defines the size property
     * @return the PropertyDescriptor
     */
    private static PropertyDescriptor getInitialPropertyDescriptor() {
        return fileDescriptor;
    }
    /* (non-Javadoc)
     * Method declared on IPropertySource.
     */
    public IPropertyDescriptor[] getPropertyDescriptors() {
        IPropertyDescriptor[] superDescriptors = super.getPropertyDescriptors();
        int superLength = superDescriptors.length;
        IPropertyDescriptor[] fileDescriptors = new IPropertyDescriptor[superLength + 1];
        System.arraycopy(superDescriptors, 0, fileDescriptors, 0, superLength);
        fileDescriptors[superLength] = getInitialPropertyDescriptor();
        return fileDescriptors;
    }
    /* (non-Javadoc)
     * Method declared on IPropertySource.
     */
    public Object getPropertyValue(Object key) {
    	Object returnValue = (key.equals(IBasicPropertyConstants.P_TEXT)) ? TextProcessor
				.process(element.getName())
				: super.getPropertyValue(key);
        if (returnValue != null) {
			return returnValue;