Bug 8772 – Cache corruption with vBulletin forum pages

• Component: Page Loading
• Status: RESOLVED DUPLICATE

This is a bug which only appears on vBulletin forums, and no other sites, as far as I can tell. Moreover, it does not appear with all pages, or with all loads of a given page, but only some of the time.

What happens is that the content of the page is laid out erroneously, with some parts missing and others misplaced. Starting with a mis-rendered page, I tried several things:

- View Source: it appears normal. When copied into a text editor and saved as html, it is rendered correctly (apart from missing images and styles): all the content is displayed and properly structured.

- Save as Source: same as above: normal markup, correct rendering when reopened.

- Saved as Web Archive: when the webarchive is reopened, Safari displays the wrong rendering again. Moreover, doing a "View Source" on this reopened page shows an altered markup; when saved as html, this markup also renders incorrectly. Extracting the page from the webarchive file manually (using plutil and uudecode) yields the same altered markup that renders incorrectly.

- Opening a new tab and pasting the address of the page that was rendered incorrectly causes the badly-rendered version to load once again, as long as the page was in the cache. Refreshing the page causes it to be reloaded from the server and then it is rendered correctly.

It seems that the html source becomes corrupted somehow, and this corrupted version is fed to the cache, the renderer and the webarchive saver, but "view source" and "save as source" see the original uncorrupted markup instead. Hopefully, this information can help locate the stage where the corruption takes place.

Created attachment 8148 [details]
Webarchive of a damaged page. The message text is not visible when the file is loaded.

This is the webarchive saved from a page that had been rendered incorrectly.

Created attachment 8149 [details]
Source of the same page.

This source was saved by using "Save as source" on the same webpage as above. In this case, the correct source is saved, even though I saved it from the same page as the webarchive, without reloading it.

Created attachment 8150 [details]
Webarchive of the correctly rendered page, saved after reloading it.

After refreshing the page, it was rendered correctly. This webarchive shows the expected rendering of the page.

[Arnold Kim]

I had the same issue:

http://bugzilla.opendarwin.org/show_bug.cgi?id=9443

[Joost de Valk (AlthA)]

This, just like bug 9443, is a dupe of bug 6314.

*** This bug has been marked as a duplicate of 6314 ***