Whitelabel page is not displayed in IE 11 in Compatibility Mode

[trung]

In IE11, Tools -> Compatibility View Settings -> Add localhost in the list
Visit http://localhost:8080/foo

It displays IE 404 instead of Spring Boot Whitelabel page.

This is due to the Accept header for Compatibility mode contains:
application/x-ms-application, image/jpeg, application/xaml+xml, image/gif, image/pjpeg, application/x-ms-xbap, application/vnd.ms-excel, application/vnd.ms-powerpoint, application/msword, */*

Hence the BasicErrorController returns the ResponseEntity instead of the "error" view.

Per https://developer.mozilla.org/en-US/docs/Web/HTTP/Content_negotiation

Not sure how best we can fix this, probably declare one more content type in the "produces" value in BasicErrorController#errorHtml?

[bclozel]

Given the current method signatures, I don't know what we could do to fix this...

    @RequestMapping(value = "${error.path:/error}", produces = "text/html")
    public ModelAndView errorHtml(HttpServletRequest request) {

    @RequestMapping(value = "${error.path:/error}")
    @ResponseBody
    public ResponseEntity<Map<String, Object>> error(HttpServletRequest request) {

Mimetypes application/x-ms-application, image/jpeg, application/xaml+xml, image/gif, image/pjpeg, application/x-ms-xbap, application/vnd.ms-excel, application/vnd.ms-powerpoint, application/msword are all application/file related and not suitable for HTML output.
Writing HTML in response of */* would work, but this would also mean that content negotiation is broken for JSON, XML, etc.

For that very specific use case, I'd try to write a Servlet Filter that adds a text/html mimetype to HTTP requests coming from that particular client. It will be a problem for all endpoints anyway.

[trung]

How about reversely provide explicit produces for JSON/XML content negotiation and default returned content type is the white label page?

Or is there a way to create error controller programmatically? We can externalized content negotiation for whitelabel page and the ResponseEntity

[bclozel]

You can configure the content negotiation to your liking (how it's operated, default content type, etc), but it's likely to break things for all other clients.

If you'd like to do that for this particular client, then the Servlet filter is in my opinion still the best choice.