getMimeTypes() race condition results in content getting served as xhtml and failing in safari

[codeconsole]

Expected Behavior

Grails core should not silently fall back to createDefaults() in getMimeTypes() — when there's no request, it should defer caching, not poison it.

org.grails.web.mime.HttpServletResponseExtension.getMimeTypes()

  public static MimeType[] getMimeTypes() {                                                                                           
      if (mimeTypes == null) {                              // ← static field, populated once
          webRequest = GrailsWebRequest.lookup();           // ← thread-local request lookup                                          
          ApplicationContext ctx = webRequest?.getApplicationContext();                                                               
          if (ctx != null) {                                                                                                          
              // CORRECT PATH: read app config via Spring                                                                             
              mimeTypes = ctx.getBean(MimeUtility).getKnownMimeTypes();                                                               
              loadMimeTypeConfig(ctx.getBean(GrailsApplication).config);                                                              
          } else {                                                                                                                    
              // WRONG-FALLBACK PATH:                                                                                                 
              mimeTypes = MimeType.createDefaults();        // [XHTML, HTML, XML, ...]                                                
          }                                                       
      }                                                                                                                               
      return mimeTypes;                                           
  } 

Actual Behaviour

No response

Steps To Reproduce

No response

Environment Information

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Example Application

No response

Version

7.0.10