284296 - DOMParser freezes Mozilla if the top element is html:script

Status: RESOLVED WORKSFORME

(Core :: XML, defect)

Description

[Ng Ming Hong]

User-Agent:       Mozilla/5.0 (Windows; U; Windows NT 5.0; en-US; rv:1.7.6) Gecko/20050223 Firefox/1.0.1
Build Identifier: Mozilla/5.0 (Windows; U; Windows NT 5.0; en-US; rv:1.7.6) Gecko/20050223 Firefox/1.0.1

DOMParser freezes when parsing a string that the top element is HTML script,
e.g. '<script xmlns="http://www.w3.org/1999/xhtml"/>'. Of course one can blame
me for parser an incorrect string. But my string is a well-formatted so it
should be parsed accordingly.

The bug is still reproducible on Mozilla 1.8b1.

P.S. If there is no xmlns, there is no problem (it is parsed as generic XML).
For other elements like p, table, hr, there is no problem too. HTML script seems
to be the only element that kills DOMParser.

Reproducible: Always

Steps to Reproduce:
1. Create a string like '<script xmlns="http://www.w3.org/1999/xhtml"/>'
2. Parse with DOMParser

Actual Results:  
The browser freezes when it loads the line with parseFromString().

Expected Results:  
Should parse accordingly if the string is well formatted.

I mark this bug as critical as it hangs the browser. But since usually people
parse a correct string to DOMParser, the bug may be less critical.

Comment 1

[Ng Ming Hong]

Attachment: Test case

If it works, it should give an alert dialog with the text "script".

Disabled JavaScript if you don't want to hang your browser.

Comment 2

[Xanthor Sccas]

Confirm on GNU/Linux with Moz 1.8b1 too

Comment 3

[Matthias Versen [:Matti]]

confirming with win2k3 and Mozilla 20050226

Comment 4

[Boris Zbarsky [:bzbarsky]]

So there seem to be two issues here:

1)  <script> as root doesn't load the script (see bug 88309)
2)  The DOMParser code spins in a tight loop calling ProcessPendingEvents() on
    the event queue it pushed until the page loads (which is forever, in this
    case, since the parser is blocked and will never unblock).  Is there a reason
    this can't use waitForEvent() and handleEvent()?  That will at least not
    freeze up the whole app (though the parseFromString call will still never
    return).

Comment 5

[Jonas Sicking (:sicking) No longer reading bugmail consistently]

This is wholly or partially a dup of bug 88309. Making dependent for now.

Comment 6

[Boris Zbarsky [:bzbarsky]]

Well... The fact that this code busy-waits while we're parsing seems wrong even
if the parsing just takes "a while" instead of "forever".  Consider a slow
server such that fetching the script just takes 10-15 seconds....

Comment 7

[Martin Honnen]

*** Bug 318934 has been marked as a duplicate of this bug. ***

Comment 8

[Cees T.]

Only a short glitch while moving the window; WFM on Firefox 4.0b7 (32 bit Windows 7).

Comment 9

[Timea Cernea [:tbabos][inactive]]

Although this is a very old bug, I can not reproduce it on the latest Firefox Nightly 87 on MacOS 10.15. Closing this as resolved:worksforme, please re-open if it is still reproducible on your side. The string "script" was displayed on my end after loading the testcase.