This is a behavior difference. For $.when( 1 ), window is the context instead of undefined, but this is closer to $.when( 1, 1 ), which has historically resolved with a context of [ window, window ].

Not since at least jQuery 1.8.3: http://jsfiddle.net/av4shtg8/ . I complained about the cast/all mixing in #2018, but lost.

This test code should not be altered, and the behavior change should be reverted. If anything, the problem is that the Callbacks apply converts our undefined context into the global object, but there's nothing we can do about that language-level operation.

But, why? What's the point of returning undefined instead of window, or vice versa? I imagine neither is being used very often. And why are we continuing to do different things for $.when( 1 ) and $.when( 1, 1 )? jQuery 1.8.3 looks just as bad, only swapped. Time to get them to do the same thing.

I can't revert this change without doing ugly things or dumping this PR and closing #2018 wontfix. The point is to make single arguments and multiple arguments do the same thing. We can either do that or we can't. I don't really care if we do undefined or window, but let's choose one or the other for all cases, not a mixture.

Either context seems sufficiently useless that it does seem unlikely anyone is using them.

I'm inclined to leave it. Returning window and [ window, window ] seems better than undefined and [ window, window ]. However, I agree that getting window out of passing undefined is an odd language quirk, but I think all the windows will be undefineds in global strict mode.

I'm inclined to leave it. Returning window and [ window, window ] seems better than undefined and [ window, window ]

Meh.

I think all the windows will be undefineds in global strict mode.

Correct.

And why are we continuing to do different things for $.when( 1 ) and $.when( 1, 1 )… Time to get them to do the same thing.`

Look, I made the same argument, but lost. And the differences go beyond context—jQuery.when( value ) and jQuery.when( value1, …, valueN ) are actually different operations, with different signatures.

I see what you did there!

var done = assert.async(). We don't need QUnit.stop anymore. 😺

Yea, I started with that. I went with QUnit.stop given how prevalent it is in our code, but I'll switch it back.

notEqual → notStrictEqual

Thanks.