MultiViewHandler#derivePhysicalViewId fails when error dispatcher is invoked on an error page mapped at virtual path

[BalusC]

• Tomcat/Spring/REST/Faces app migrated from Mojarra 2.3.13 to Mojarra 4.0.11
• have FacesServlet mapped at virtual path, e.g. *.faces
• have a Faces page as (general) <error-page> at virtual path, e.g. /error.faces
• have another servlet running in same app, e.g. Jakarta REST at /api/* or even (Spring) WebSocket handler at /
• have it throw an exception and invoke ERROR dispatcher
• ERROR dispatcher invokes FacesServlet, because error page is a Faces page
• Mojarra's MultiViewHandler#derivePhysicalViewId attempts to figure out the mapping used by FacesServlet
• expects it to be *.faces, but it's actually /api/* or /, so it cannot find /error.xhtml anymore
• error page rendering completely fails

Appears to be regression introduced by the change of the mapping inspection to utilize the in Servlet 4 introduced HttpServletRequest#getHttpServletMapping as per 45848de

Work around: add *.xhtml mapping to FacesServlet in web.xml and configure error page on /error.xhtml instead.

[BalusC]

Norepro in GlassFish. Most likely Tomcat bug.