Bug 37345 javaElementFilters extension point isn't robust against errors in the plugin.xml
1) create a javaElementFilters extension, but leave the markup in the plugin.xml incomplete 2) start-up the workbench -> the package explorer doesn't come up The reason is that the javaElementFilters extension point implementation fires an assertion when the xml isn't complete. This is not correct since this isn't a programming error. In addition, an error in the plugin.xml shouldn't never block the workbench from properly coming up.
org.eclipse.jdt.ui/ui/org/eclipse/jdt/internal/ui/filters/FilterDescriptor.java
description= ""; 
		return description;
	}
	/**
	 * @return <code>true</code> if this filter is a custom filter.
	 */
	public boolean isPatternFilter() {
		return getPattern() != null;
	}
	/**
	 * @return <code>true</code> if this filter is a pattern filter.
	 */
	public boolean isCustomFilter() {
		return fElement.getAttribute(CLASS_ATTRIBUTE) != null;
	}
	/**
	 * Returns <code>true</code> if the filter
	 * is initially enabled.
	 * 
	 * This attribute is optional and defaults to <code>true</code>.
	 */
	public boolean isEnabled() {
		String strVal= fElement.getAttribute(ENABLED_ATTRIBUTE);
		if (strVal == null)
			
			strVal= fElement.getAttribute(SELECTED_ATTRIBUTE);
		return strVal == null || Boolean.valueOf(strVal).booleanValue();
	}
	/* 
	 * Implements a method from IComparable