Theme Customizer is non-functional in IE11

[celloexpressions]

Changing a control throws a JS error, and thus prevents the preview from updating and or the save button from becoming enabled.

The error is invalid calling object on line 265 of custommize-base.js.

Doesn't seem to affect Chrome or Firefox.

Introduced in [26548].

[nacin]

We haven't updated Underscore.js since 1.4.4. I haven't seen anything in the logs to suggest that 1.5.2's version of _.isEqual would fix this.

[nacin]

At worst we can revert [26548] and save it for 3.9. I would rather not have that optimization in, if it causes problems. If it's caused at least one issue, there's bound to be another.

[ocean90]

I found ​https://github.com/paulmillr/exoskeleton/issues/36 and some other pages.

toString.call(a) should be replaced by Object.prototype.toString.call(a). This should be also reported upstream.
Patch attached.

[ocean90]

Seeing also an issue in IE 8 for hasOwnPropertery, see ​http://stackoverflow.com/questions/8157700/object-has-no-hasownproperty-method-i-e-its-undefined-ie8.

So +1 for a revert and review this again for 3.9, since the same code exists in 1.4.4 and us used by the media modal where _.isEqual it works.

[nacin]

In 26702:

Customizer: Revert [26548], removing _.isEqual() for proper object comparison.

This broke the customizer in IE 11, with possibly other side effects. Revisit in 3.9.

Also reverts [26632].

see #26061 (reopens), fixes #26438.

[EPinci]

Header image changing now works fine.
Changing header text color doesn't live preview as it does on Chrome.

[ocean90]

EPinci,
works for me in IE 11 with Twenty Fourteen.

Please open a new ticket if you think this is a bug in 3.8, but with some more Infos, like IE version, theme name and so on.

Re-closing since the reported issue was fixed.