deleting all input might cause TypeError: Cannot call method 'replace' of undefined

[metamatt]

If I configure jquery-textcomplete with a completion strategy based on @, and type @xyz and backspace over it a few times (and keep pressing backspace after I've erased all input), sometimes I get it to throw this exception:

Uncaught client exception: TypeError: Cannot call method 'replace' of undefined
    at Function.jQuery.extend.camelCase (http://test:1080/static/lib/jquery/jquery.js:620:17)
    at Function.jQuery.extend.css (http://test:1080/static/lib/jquery/jquery.js:7048:22)
    at null.<anonymous> (http://test:1080/static/lib/jquery/jquery.js:6920:12)
    at Function.jQuery.extend.access (http://test:1080/static/lib/jquery/jquery.js:885:8)
    at jQuery.fn.extend.css (http://test:1080/static/lib/jquery/jquery.js:6902:17)
    at ListView.$.extend.setPosition (http://test:1080/static/lib/jquery-textcomplete/jquery.textcomplete.js:462:18)
    at Completer.$.extend.renderList (http://test:1080/static/lib/jquery-textcomplete/jquery.textcomplete.js:179:18)
    at http://test:1080/static/lib/jquery-textcomplete/jquery.textcomplete.js:196:16
    at http://test:1080/static/lib/jquery-textcomplete/jquery.textcomplete.js:76:20

I think this happens when the server is slow to respond (I was introducing intentional delays to reproduce another bug) and the callback arrives late.

This is easy to fix (don't call $el.css(null)); would you like a PR?

[yuku]

Hi @metamatt
Thank you for reporting the issue! This is a bug 👾

setPosition is called with the result of getCaretPosition (here) and getCaretPosition returns undefined when a caret is located at the head of textarea (here).
Don't call $el.css(null) is 🆗 , but I think removing this line is better :)

[yuku]

By the way, all PR is welcome.