202
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Changes
→Proposal
Add a virtual function to nsDocLoader "OnRedirectStateChange". This function would be called manually from OnChannelRedirect will full information on the source and destionation channels. DocShell will provide an implementation of this function, and we can move the redirect handling code from OnStateChange to there.
We could add a new redirect function to the existing nsIGlobalHistory2 or add it in a new interface nsIGlobalhistory3. Adding to the existing interface is cleaner, but would force embedders to update their history code. A new interface could be optional (docshell would fall back on AddURI if history didn't QI to nsIGlobalHistory3) so embedders would not have to change, but it would make history more difficult to understand. Probably adding an additional method is preferrable; the GeckoFlags function was successfully added without too much pain to GlobalHistory2 in Firefox 1.5.
The docshell would be extended to support nsIWritablePropertyBag. When the history system gets visit notifications, it can store necessary state on the docshell (probably just a 64-bit visit ID number). This way, it can associate a given page visit as coming from a specific docshell, and know which specific page visit it came from, even if the same document is open in more than one docshell.
