Bug 28510 java build path inconsistency [build path]
20021216 select rt.jar in the package explorer open properties it allows you to set the javadoc location but for source attachment you are sent somewhere else it's inconsistent - on the java build path they both look sort of the same (they sit under the same node in the tree)
org.eclipse.jdt.ui/ui/org/eclipse/jdt/internal/ui/wizards/buildpaths/CPListElement.java
private void attributeChanged(String key) {
		fCachedEntry= null;
	}
	
	
	/*
	 * @see Object#equals(java.lang.Object)
	 */
	public boolean equals(Object other) {
		if (other != null && other.getClass() == getClass()) {
			CPListElement elem= (CPListElement)other;
			return elem.fEntryKind == fEntryKind && elem.fPath.equals(fPath);
		}
		return false;
	}
	
	/*
	 * @see Object#hashCode()
	 */
	public int hashCode() {
		return fPath.hashCode() + fEntryKind;
	}
	/**
	 * Returns if a entry is missing.
	 * @return Returns a boolean
	 */
	public boolean isMissing() {
		return fIsMissing;
	}
	/**