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[whatwg] Script/parser interaction bug?

From: Kartikaya Gupta <lists.whatwg@stakface.com>
Date: Tue, 20 Jan 2009 00:43:51 +0000
Message-ID: <20090120004348.78E3B828E@looneymail-mx3.g.dreamhost.com>
I have a test case that works in major browsers (FF, Opera, Safari, IE6) but that I don't think would work if the they followed the behavior as currently specified in HTML5. I've put the test case online:

http://stakface.com/pub/mango/ext7.html

The assertion "document.getElementById('r').firstChild.data == 'PASS'" is true after the page has loaded, whereas according to the spec I don't think it shouldn't be.

The steps are roughly as follows:
- tokenize/treebuild ext7.html until the first closing script tag is found (for the 7a.js script)
- run the script. this sets 7a.js to be the "pending external script"
- execute the "pending external script" (7a.js) since it's not a re-entrant invocation of the tree builder
--- insert the 7b.js line into the input stream
--- tokenize/treebuild the 7b.js script tag until the </script> for 7b.js is found
--- run the script. this sets 7b.js to be the "pending external script"
--- now, since there is a "pending external script" and this is a re-entrant invocation, set the pause flag to true and bail
--- insert the other stuff in 7a.js into the input stream
--- since the parser pause flag is set this other stuff does NOT get tokenized/treebuilt yet
- 7a.js finishes executing, and now we have a new "pending external script", which is 7b.js
- execute 7b.js
--- throws
- continue processing input stream (this now has the contents of the document.write calls from 7a.js, line 2 onwards)
- tokenize/treebuild the input stream until the </script> that was document.write'd at the bottom of 7a.js is encountered
- execute the script
--- insert the div into the input stream
--- since the parser pause flag is still set the div does NOT get tokenized/treebuilt
--- run the line that sets .firstChild.data to PASS. since the div isn't in the DOM yet, this throws and the script is done
- unwind back to the treebuilder, which clears the parser pause flag since the script nesting level drops to zero
- tokenize/treebuild the input stream, which contains the div tag
- add div with content FAIL to the DOM
- done

Here, I think the pause flag needs to get cleared earlier, so that when the div is inserted into the input stream, it gets tokenized and added to the DOM. This would make the behavior consistent with what I'm seeing in major browsers. Thoughts?

kats
Received on Monday, 19 January 2009 16:43:51 UTC

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