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ASF subversion and git services commented on WICKET-6908: --------------------------------------------------------- Commit 05ab77655fb00d27ade1402b72db1dc6968b3dbe in wicket's branch refs/heads/WICKET-6908-detach-failure from Sven Meier [ https://gitbox.apache.org/repos/asf?p=wicket.git;h=05ab776 ] WICKET-6908 detach all handlers even if one throws a RuntimeException > Possible bug / edge case where page is not detached > --------------------------------------------------- > > Key: WICKET-6908 > URL: https://issues.apache.org/jira/browse/WICKET-6908 > Project: Wicket > Issue Type: Bug > Components: wicket-core > Affects Versions: 9.3.0, 9.4.0 > Reporter: Sebastian Gooren > Assignee: Sven Meier > Priority: Minor > Attachments: quickstart.zip > > > Today I spent the better part of my day investigating a bug report regarding > a hibernate LazyInitializationException. > Since we use detaching models everywhere and (in general) never see such > issues anymore, this one was interesting :-) > > After much debugging I found out what is happening. > > We have a page which has a database model + links for prev/next item (in the > database). > When the users double-clicks on one of the links, the first click is OK, and > the second click throws a StalePageException during request cycle processing. > > So far, normal. > > However, stepping through the wicket code, this is what happens: > > 1) Resolve to ListenerRequestHandler, execute it, throws StalePageException > 2) exception mapper handles this and we execute a RenderPageRequestHandler, > which re-renders the page > 3) the request cycle detaches, which delegates in part to > RequestHandlerExecutor.detach() > 4) The handlers to detach are both handlers from step 1 and 2; During the > detach of ListenerRequestHandler, it initializes ListenerLogData, which (in > the PageLogData ctor) throws the StalePageException again! > 5) The second handler (RenderPageRequestHandler) is not detached, thus all > models in the page are not detached > 6) The user clicks on a link and boom, the models are all still attached and > there we get the LazyInitializationException > > I think that (a) RequestHandlerExecutor.detach() should ensure all handlers > are detached, and (b) that failing to collect LogData should not stop the > detaching of a request handler. > > What do you think? > > I tried to make the simplest possible Quickstart to demonstrate this. > > Weird stuff: on the homepage of the quick start, the page is properly > detached when a stale link is clicked; > On another (test) page, the page is not properly detached. > > Steps to reproduce: > > Run Quickstart > Click on “Test” link on homepage > Observe that the following is logged: > > Model still attached? false > Page detaching > > Now click on "Click me (stale link)!” > Now refresh the page (re-render) > > Observe that the following is logged: > > Model still attached? true > Page detaching > > —> So the page was not detached > > These steps don’t have the same result on the homepage. So my guess is there > is some relation to the fact that we are interacting with a stateful, > non-mounted page. -- This message was sent by Atlassian Jira (v8.3.4#803005)