Bug 180758 [IDE] Deleting a project but not the contents asks if you want to delete read-only files
I have noticed that in 3.3M6, if I delete a project that has read-only files in it, it will prompt if I want to delete the files even if I select "Do not delete contents". The files are not actually deleted, but the error dialog should not be presented to the user since the files are not actually being deleted. I don't remember seeing this in 3.3M4 or earlier.
bundles/org.eclipse.ui.ide/src/org/eclipse/ui/ide/undo/AbstractResourcesOperation.java
if (!resourceDescriptions[i].isValid()) {
				markInvalid();
				return getErrorStatus(UndoMessages.AbstractResourcesOperation_InvalidRestoreInfo);
			} else if (!allowOverwrite
					&& resourceDescriptions[i].verifyExistence(false)) {
				
				markInvalid();
				return getErrorStatus(UndoMessages.AbstractResourcesOperation_ResourcesAlreadyExist);
			}
		}
		return Status.OK_STATUS;
	}
	/**
	 * Compute the status for deleting resources. A status severity of
	 * <code>OK</code> indicates that the delete is likely to be successful. A
	 * status severity of <code>ERROR</code> indicates that the operation is
	 * no longer valid. Other status severities are open to interpretation by
	 * the caller.
	 * 
	 * Note this method may be called on initial deletion of a resource, or when
	 * a create or delete operation is being undone or redone. Therefore, this
	 * method should check conditions that can change over the life of the
	 * operation, such as the existence of the resources to be deleted. One-time
	 * static checks should typically be done by the caller (such as the action
	 * that creates the operation) so that the user is not continually prompted
	 * or warned about conditions that were acceptable at the time of original
	 * execution.
	 */
	protected IStatus computeDeleteStatus() {
		if (resources == null || resources.length == 0) {