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
* equivalent {@link ParameterizedCommand} using the
	 * {@link CommandManager#deserialize(String)} method.
	 * <p>
	 * The syntax of the returned {@link String} is as follows:
	 * </p>
	 * 
	 * <blockquote>
	 * <code>serialization = <u>commandId</u> [ '(' parameters ')' ]</code><br>
	 * <code>parameters = parameter [ ',' parameters ]</code><br>
	 * <code>parameter = <u>parameterId</u> [ '=' <u>parameterValue</u> ]</code>
	 * </blockquote>
	 * 
	 * <p>
	 * In the syntax above, sections inside square-brackets are optional. The
	 * characters in single quotes (<code>(</code>, <code>)</code>,
	 * <code>,</code> and <code>=</code>) indicate literal characters.
	 * </p>
	 * <p>
	 * <code><u>commandId</u></code> represents the command id encoded with
	 * separator characters escaped. <code><u>parameterId</u></code> and
	 * <code><u>parameterValue</u></code> represent the parameter ids and
	 * values encoded with separator characters escaped. The separator
	 * characters <code>(</code>, <code>)</code>, <code>,</code> and
	 * <code>=</code> are escaped by prepending a <code>%</code>. This
	 * requires <code>%</code> to be escaped, which is also done by prepending
	 * a <code>%</code>.
	 * </p>
	 * <p>
	 * The order of the parameters is not defined (and not important). A missing
	 * <code><u>parameterValue</u></code> indicates that the value of the