fix for 1.2.6: name undefined in attr()

[sgbeal]

Hi!

In attr(), from 1.2.6:

attr: function( name, value, type ) {

var options = name;

Look for the case where we're accessing a style value if ( name.constructor == String )

...

i have some code which will run just fine on 1.2 except that "name is undefined" (see above: name.constructor) in some cases and that's breaking my app. i found that by changing attr() slightly to:

attr: function( name, value, type ) {

... if ( name && (name.constructor == String) )

i could get my code to work in both 1.2.6(+patch) and 1.3.

:)

[dmethvin]

Please reopen with a test case that shows when the problem occurs.