Very large pages (800,000 characters) view and edit slowly, but cannot be saved.

A customer reported a problem with a very large page. After some investigation, it appears that pages over a certain size cannot be saved in Firefox. In my testing, the attached file (800K.txt) can be used to reproduce the problem as follows:

1. Copy the contents of the file into a new page
2. Save the page
3. Edit the page
4. Attempt to save the page again
5. The error varies depending on the browser. Some browsers (Firefox 3.0 on OS X, Firefox 3.5 on Windows) churn indefinitely. When running Firefox 3.5 through a proxy (such as Fiddler), the error "You must enter a title" eventually appears. The same message appears when saving using Internet Explorer 7 (no proxy).

The problem occurs with both Confluence 2.10.3 and Confluence 3.0.0_01. Interestingly, the problem does not occur when using Safari on OS X, the page saves as expected.

In my testing, the problem does not occur with a 600K file, but occurs with a 700K file or larger.

The obvious workaround is to break down very large pages into sections and use the {include} macro. In my opinion, adding a note about splitting the content to the fix for CONF-12773 would address this as well.