Will this code lead to an object not being disposed?

Question

Say I have the following code:

 SPList promo1List = site.WebApplication.Sites[0].RootWeb.Lists.TryGetList("promotions");

Will this lead to the SPSite object Sites[0] not being disposed? I ran SPDisposeCheck against my code and it came up with a bunch of warnings about the above.

According to their documentation: SPSiteCollection[] indexer returns a SPSite object which needs to be disposed.

Is this accurate or is this just a false positive?

Answer 1

Yes, this code leads to memory leak.
I prefer to use this (or this one for 2007 sharepoint) page every time, when I doubt if object should be disposed. According section SPSiteCollection [ ] Index Operator you must dispose SPSite object.

So, in order to correct dispose SPSite in your example, you need to use this code:

using (var mySite = site.WebApplication.Sites[0])
{
    SPList promo1List = mySite.RootWeb.Lists.TryGetList("promotions");
    //no need to dispose RootWeb, because the dispose cleanup for RootWeb is handled 
    //automatically by both SharePoint Foundation and SharePoint Server.
}