[webkit-dev] SupportImage[Resource]MIMEType

[Rudi Sherry]

I'm looking into a problem where embedded PDFs don't invoke a WebKit  
plugin.

I found that
    <object data="url-to-pdf" ... >
with a "type" property works fine (invokes the PDF plugin), but
    <object data="url-to-pdf" type="application/pdf" ... >
simply shows the first page of the PDF in the embedding location as  
an image.

I tracked it down to the fact that HTMLObjectEelement::isImageType()  
is returning 'true' for "application/pdf"; this happens because  
Image::supportsType() looks at all the types that could be an image.   
Since it returns TRUE, this becomes a CachedImage and it never goes  
out to WebKit to check if any plug-ins support this type.


Image::supportsType() calls +[WebCoreFrameBridge  
supportedImageResourceMIMETypes] to get the list.  There is also + 
[WebCoreFrameBridge supportedImageMIMETypes], which is the same list  
except specifically excluding the hard-coded strings "application/ 
pdf" and "application/postscript".


Does anyone know why are there two different methods for returning  
the image mime types -- whose only difference are the pdf/postscript  
types?  Neither are called from within WebCore itself.


Another tantalizing tidbit is that there is a hidden preference  
"WebKitOmitPDFSupport", used by WebKit (but not WebCore), that will  
remove some built-in PDF support from numerous places... but not,  
unfortunately, from embedded objects as they're being parsed.

Does anyone on this list know more about the history or design of all  
this?

Thanks,
Rudi