in 4.x you could go into the pref ui, and control what plugin/helper/internal browser itself was used to handle different mimetypes. i can't seem to find a way to do this. as a result, you're at the mercy of the registration of plugins, etc. for example, moz supports png, but on a mac or pc with quicktime installed, quicktime says it can handle image/png so it get's farmed off the the plugin instead, which doesn't make a lot of sense. it's also ugly when you have more then one plugin that can support a format, in that the user doesn't get control over which one does the final handling for them. [ sorry if this was a dup, couldn't find it ]

*** This bug has been marked as a duplicate of 19118 ***

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