On 18 Sep 2012, at 22:33, Thomas Geymayer wrote: > While searching for the reason of crashing FlightGear if trying to > remove the nodes of the previously selected airport in the new Select > Airport Dialog I stumbled upon a problem with the behavior of > SGPropertyNode::removeChild. If you remove a child then fireChildRemoved > is triggered and every listener is getting informed. The problem is that > it is only called for the node being removed but for non of it's child > nodes. So if you listen upon a specific node being removed and instead a > parent node is being removed you will never get notified and have a > pointer to an invalid part of your memory which can cause a crash :) > > I've pushed a commit witch recursively triggers childRemoved for all > nodes controlling the canvas. Any objections on moving this behavior > directly into simgear?
I don't think firing this recursively is a good idea - it means remove nodes near the root of the tree becomes very high cost. Isn't it better to just document the behaviour very clearly somewhere, and modify the listeners that care about it (which are very few). In other words, the fix is to have the listener watch all the parents (ancestors) that might possibly be removed. I appreciate that's a little ugly, but it keeps the balance of work the right way around - removing nodes stays generally cheap and simple, and listeners that care about deeply-nested children being remvoed have to watch for that explicitly. James ------------------------------------------------------------------------------ Live Security Virtual Conference Exclusive live event will cover all the ways today's security and threat landscape has changed and how IT managers can respond. Discussions will include endpoint security, mobile security and the latest in malware threats. http://www.accelacomm.com/jaw/sfrnl04242012/114/50122263/ _______________________________________________ Flightgear-devel mailing list Flightgear-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/flightgear-devel
