Bug 123040 [Commands] request: display help topic
I'm going to attach a patch to "command-ify" the opening of help topics. The command takes a parameter which is the href of a help topic. The default handler uses IWorkbenchHelpSystem.displayHelpResource(String) with the href parameter. If no parameter was given, the default handler calls IWorkbenchHelpSystem.displayHelp() instead to simply open the help system. Note that this looks like it should be opened against User Assistance, but the plugins that should be patched (I think) are org.eclipse.ui and org.eclipse.ui.workbench, so I opened against UI.
bundles/org.eclipse.core.commands/src/org/eclipse/core/commands/ParameterizedCommand.java
* command to have the same identifier.
	 * 
	 * @return The command; never <code>null</code>, but may be undefined.
	 */
	public final Command getCommand() {
		return command;
	}
	/**
	 * Returns the command's base identifier. It is possible for more than one
	 * parameterized command to have the same identifier.
	 * 
	 * @return The command id; never <code>null</code>.
	 */
	public final String getId() {
		return command.getId();
	}
	/**
	 * Returns a human-readable representation of this command with all of its
	 * parameterizations.
	 * 
	 * @return The human-readable representation of this parameterized command;
	 *         never <code>null</code>.
	 * @throws NotDefinedException
	 *             If the underlying command is not defined.
	 */
	public final String getName() throws NotDefinedException {
		final StringBuffer nameBuffer = new StringBuffer();
		nameBuffer.append(command.getName());
		if (parameterizations != null) {
			nameBuffer.append(" (");