limitTo: Ignore `limit` when `undefined`

[gkalpak]

Currently, passing an undefined limit to the limitTo filter will return an empty array/string.
I would expect filtering to be skipped and the original input returned, when the limit argument is undefined.

E.g.:

Limit: <input type="number" ng-model="limit" />
Items: <ul><li ng-repeat="item in items | limitTo:limit">...</li></ul>

Before interacting with the input (i.e. explicitly specifying a limit), I would expect all items to be listed.
What happens instead, is that no item is listed, until a valid integer number is specified.

Although there are ways around this limitation (i.e. detecting undefined and set limit to Infinity), they are unnecessrily verbose (imo).

[pkozlowski-opensource]

It kind of makes sense what you are saying and I think that the current behavior is bogus for non-string inputs. Having said this it would be a breaking change (see those tests:

angular.js/test/ng/filter/limitToSpec.js

Lines 45 to 51 in 85758ce

	it('should return an empty string when X cannot be parsed', function() {
	expect(limitTo(str, 'bogus')).toEqual("");
	expect(limitTo(str, 'null')).toEqual("");
	expect(limitTo(str, 'undefined')).toEqual("");
	expect(limitTo(str, null)).toEqual("");
	expect(limitTo(str, undefined)).toEqual("");
	});

) so we shouldn't be doing this before 1.4. But yeh, let's revisit this as part of 1.4.

[pkozlowski-opensource]

Oh, actually it is fine for arrays. But yeh, we can revisit behavior for undefined in 1.4.x

[marcin-wosinek]

I'm taking look at this. Should it return input unchanged only for undefined and 'undefined'; or for all bogus values?