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Firefox 22.0 serious closure bug

  • 4 risposte
  • 2 hanno questo problema
  • 2 visualizzazioni
  • Ultima risposta di cor-el

mccodev
mccodev
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We have run into what seems like a serious closure bug in Firefox 22.0.

The simple following code executes fine in IE and chrome etc. but fails in a very scary way in FireFox - it thinks the function is undefined !!!

if (true) { 

   test();

   function test()  {
       alert("success")
   }

}

If the code is executed outside of the if statement (or if just the function definition is moved outside the if statement) everything is ok.

The same error occurs (not defined) inside other closures like do .. while etc.

We are scared. What did we miss?

We have run into what seems like a serious closure bug in Firefox 22.0. The simple following code executes fine in IE and chrome etc. but fails in a very scary way in FireFox - it thinks the function is undefined !!! if (true) { test(); function test() { alert("success") } } If the code is executed outside of the if statement (or if just the function definition is moved outside the if statement) everything is ok. The same error occurs (not defined) inside other closures like do .. while etc. We are scared. What did we miss?

Modificato da mccodev il

Soluzione scelta

This has been solved. Firefox is different from other browsers (as we know)... but here's why...

http://stackoverflow.com/questions/18079086/firefox-22-0-scope-bug

Leggere questa risposta nel contesto 👍 0

Tutte le risposte (4)

cor-el
cor-el
  • Top 25 Contributor
  • Moderator
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Just swap the order of the two statements and place the function definition before calling the function. 

if (true) {
   function test()  {
       alert("success")
   }
 test();
}
mccodev
mccodev Utente che ha posto la domanda
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Thank you for your time and advice... but that wasn't my point at all.

The point is this seems to be quite a big bug. Javascript by it's very nature can forward reference within scope. As I suggested, the code works fine in all other browsers.

I'm worried this is a huge new bug in Firefox - or worse a secret breaking change. Has anyone got a lead on this? This should work right ???? Is it just me??

Modificato da mccodev il

mccodev
mccodev Utente che ha posto la domanda
more options

Soluzione scelta

This has been solved. Firefox is different from other browsers (as we know)... but here's why...

http://stackoverflow.com/questions/18079086/firefox-22-0-scope-bug

cor-el
cor-el
  • Top 25 Contributor
  • Moderator
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I've marked your previous post as the solution since you wrote that it has been solved (Firefox doesn't allow forward reference if a function is defined within a block).