94308 - document.write document.documentElement properties causes infinite loop

Status: RESOLVED INVALID

(Core :: DOM: Core & HTML, defect)

Description

[basic]

Got this from the n.p.m.dom newsgroup

The code below throws moz into an infinite loop. It might be related or dup of
bug 92425

<script type="text/JavaScript" language="javascript">
function propertySlideShow(anyObject)
{
  var s = "";
  for (var prop in anyObject){s = prop + " = " + anyObject[prop] +
"\n\n";document.write(s)}
}
propertySlideShow(document.documentElement)
</script>

Comment 1

[basic]

Attachment: testcase

Comment 2

[Brian King [:kinger]]

This cause an error for me (was previously working):

    with (window.frames[0].document) {
        open();
        write('foo');
        close();
    }
The error is (note nsIDOMNSHTMLDocument.write part)
###*** Error/XPConnect JavaScript: chrome://komodo/content/editor/scintillaview.
js(485): [Exception... "Component returned failure code: 0x804e03f7 [nsIDOMNSHTM
LDocument.write]"  nsresult: "0x804e03f7 (<unknown>)"  location: "JS frame :: ch
rome://komodo/content/editor/scintillaview.js :: anonymous :: line 485"  data: n
o]
###*** Warning/: chrome://komodo/content/koGlobalOverlay.js(202): An error occur
red executing the cmd_print command\012[Exception... "Component returned failure
 code: 0x804e03f7 [nsIDOMNSHTMLDocument.write]"  nsresult: "0x804e03f7 (<unknown
>)"  location: "JS frame :: chrome://komodo/content/editor/scintillaview.js :: a
nonymous :: line 485"  data: no]

Comment 3

[Fabian Guisset]

Not DOM Events -> JS Engine for initial debugging.
Phil, I really need your help on this one. I tried to figure out where we hang,
but neither gdb nor the debugger on windows give any useful information (the
stacktrace is somewhere in nspr land). 
Also note that we don't hang if I call that script from an onclick in a button
(after the page has loaded).
I'm really at a loss here.
Feel free to reassign to.. hmm.. DOM0 I guess if it isn't the js engine fault

Comment 4

[Phil Schwartau]

The problem is this:

As the page is loading, propertySlideShow() accesses all the enumerable 
properties of document.documentElement and document.writes each one.

But then each of these strings become new properties of 
document.documentElement! So the loop can never end.

I would like to say this is just a coding error. But then why do 
NN4.7 and IE4.7 load the testcase and finish, whereas Mozilla hangs?

Reassigning to DOM Level 0 for further analysis -

Comment 5

[Phil Schwartau]

Really reassigning 

Comment 6

[Johnny Stenback (:jst)]

Future.

Comment 7

[basic]

Phil: maybe because NN4.7 and IE4.7 does not implement document.documentElement ?

in WinIE5.0 sometimes the testcase finish loading with a blank page, sometimes
filled with properties = values and sometimes never finish loading at all.

Comment 8

[Johnny Stenback (:jst)]

That's right, NN4x did not have a document.documentElement property, not sure
about IE4...

Comment 9

[Johnny Stenback (:jst)]

Mass-reassigning bugs to [e-mail]

Comment 10

[Garrett Smith]

I agree with comment 4. This is a coding error. To examine the props, you'll
have to open a new window. 


// loop through a collection 
  for (var prop in anyObject) {
      s = prop + " = " + anyObject[prop] + "\n\n";
      
    // modify the collection.
      document.write(s)}
}
This should cause infinite recursion.



try writing to a new window. 

var x = window.open();
for(prop in obj)
   x.document.writeln(prop + " = " + anyObject[prop] + "\n\n");



Can we mark this INVALID?

Comment 11

[Christopher Aillon (sabbatical, not receiving bugmail)]

Okay.  marking invalid.  If anyone disagrees, please explain why it is a Mozilla
bug and then feel free to re-open.