minified manipulation methods fail on oldIE with XML

[gibson042]

A handful of our methods (among them the manipulation-module internal getAll) employ a clever typeof node.<DOM method> !== "undefined" hack because oldIE sometimes tries to evaluate the methods (and fails for insufficient arguments) if we test them directly.

Unfortunately, UglifyJS undoes all our efforts and turns the pattern into n.<DOM method>!==<undefined>. Core module test "jQuery(selector, xml).text(str) - Loaded via XML document" fails on oldIE when run against minified source for precisely this reason.

Secondarily, we should check jquery.min.js with TestSwarm. :)

[Rick Waldron]

That's so annoying.

[jaubourg]

+1 on testing the minified build on TestSwarm. Has the uglify team been notified of this? Would it be possible to get an option to opt out of this optimization?

[gibson042]

Replying to jaubourg:

+1 on testing the minified build on TestSwarm. Has the uglify team been notified of this? Would it be possible to get an option to opt out of this optimization?

I'm checking/posting now.

[gibson042]

Reported at ​https://github.com/mishoo/UglifyJS2/issues/105

[gibson042]

For the record, safer auto-compressed output will add about 69 bytes after gzip. We can save more than half of that (+26) by comparing against a global variable instead of literal "undefined", and we can do it without waiting on dependency upgrades. Expect something along those lines later this week.

[Richard Gibson]

Fix #13315: compare typeof node.method to var instead of literal "undefined" for safer uglification

Changeset: ec9b38a34fb9bd81d1903cf12b69466f699abca5

[gibson042]

As an interesting side note, minification also undoes some of our performance micro-optimizations, replacing undefined/true/false respectively with void 0/!0/!1 and making typeof comparisons loose (e.g., "string"==typeof v instead of "string"===typeof v).

I haven't checked on the latter size optimization, but the former is configurable and saves something like 40 bytes after gzip.

Also interesting, but probably not actionable, is that minification maps our internal variable jQuery to a two-character identifier. Swapping it with a one-character identifier would save another 40 bytes gzipped.

[dmethvin]

#13328 is a duplicate of this ticket.

[dmethvin]

#13320 is a duplicate of this ticket.

[Richard Gibson]

Fix #13315 for IE9: compare typeof xmlNode.method to var instead of literal "undefined" for safer uglification (cherry picked from commit ec9b38a34fb9bd81d1903cf12b69466f699abca5)

Changeset: 64b55f0b7912d96c3bdae8c771b4da99c96954fd