Possible solution to the latter:

/(?![^\\\\\\[]*\\])(?![^\\\\\\(]*\\))/

But this way the class regex (and the others) will wrongly match if a backslash is present after a dot inside an attribute selector:

´[foo=.ba\\r]´

(besides the opening brackets, as in the first issue)

I've been thinking about the first issue and came up with a simple solution to detect if there's still an erroneous match inside an attribute selector. It doesn't impact speed - maybe only in these edge cases a bit - but the only problem is that it should be in the Sizzle.filter function, which isn't really the place where this should ideally happen. Here's a standalone code that demonstrates the logic:

var classregex = /\\.((?:[\\w\\u0128-\\uFFFF_-]|\\\\.)+)(?![^\\\\\\[]*\\])(?![^\\\\\\(]*\\))/;
var attrregex = /\\[((?:[\\w\\u0128-\\uFFFF_-]|\\\\.)+)\\s*(?:(\\S?=)\\s*(['"]*)(.*?)\\3|)\\]/;
var expr = 'input[name=".types["]' //original example
var expr = "input[name='.types\\\\.asdf']";
 //this would match ".types" too beacause of the fix for  in the previous comment
var match = classregex(expr);

//
// and in Sizzle.filter the following would go after 
// 
//

var nextpos=match && match.index + match[0].length;
if( nextpos && expr.charAt( nextpos ).match(/[\\[\\(\\\\]/) ){
  var isattr=attrregex(expr);
  if( isattr && ( (isattr.index + isattr[0].length) > nextpos ) )
    console.log("false positive"); // continue;
}

It's getting even more interesting :)

I tried to apply the above but the chunker splits this selector into two:

input[name=".types["]

becomes

input and name=".types["]

Now looking at the chunker this part: [^ >+~,(\\[]+ is interesting -- why does it have to split the selector by the openening braces? Removing (\\[ seems to solve this but I guess they have some purpose...

Btw, looks like people are already running into this bug: http://groups.google.com/group/jquery-en/browse_thread/thread/eefe67dca10c8163

I moved the discussion of input[name^="types["] style selectors to bug #3928.

Per John in #3928, fixed in SVN rev [6143].

I reopen this because #3928 was just a related problem. The original issue comes up when there's an opening bracket and a dot too in the attribute filter beacause that causes the class filter to match inside it (and the same goes for colons and pseudos).

I am still seeing this issue in 1.3.2.

It appears that as long as a left bracket occurs after a dot (even if it is not the first character in the string) the element will not be properly selected. For example:

div[name='a.b[c'] will fail to select

whereas:

div[name='a.b]c'] works fine...

Confirmed. test case

Will check this out later, post-1.5.

Confirmed in bug triage, but low priority.

#5482 is a duplicate of this ticket.

valid if escaped: http://jsfiddle.net/yjCW7/1/