With inheritance, HstSiteMapItemService uses the wrong siteMapRootNodePath, which leads to StringIndexOutOfBoundsException

In HstSiteMapItemService, line 129:
this.id = nodePath.substring(siteMapRootNodePath.length()+1).intern();

When using inheritance in HST configurations, the nodePath can be in the super-configuration, and the siteMapRootNodePath refers to the sub-configuration.

Examples:

HST configurations: myhippoproject-A inherits from myhippoproject
nodePath: /hst:hst/hst:configurations/myhippoproject/hst:sitemap/home
siteMapRootNodePath: /hst:hst/hst:configurations/myhippoproject-A/hst:sitemap
id = "me" (instead of "home")

HST configurations: myhippoproject-Awesome inheritsfrom myhippoproject
nodePath: /hst:hst/hst:configurations/myhippoproject/hst:sitemap/home
siteMapRootNodePath: /hst:hst/hst:configurations/myhippoproject-Awesome/hst:sitemap
id = StringIndexOutOfBoundsException (instead of "home")