This is more a question than actually a post to show you something. But I think that this question is not suitable for Stackoverflow, so I decided to put it here.
Today I tried to read a session scope variable in my Java code. The code is being executed in the computed value of a computed text element on an XPage - and not used as a bean.
The XPage is loaded after several sessionScoped variables were set before in another page.
When I was trying to access the variable via
ExtLibUtil.getSessionScope().get("myKey")
it returned null and not the value I expected (in this case a long).
After searching for the cause I just tested the other way to gain access to the sessionScope map via
Map sessionscope = (Map) ExtLibUtil.resolveVariable(FacesContext.getCurrentInstance(), "sessionScope");
This one worked, returned the map and I could access the value via the get("myKey") method.
I am pretty sure that this works as designed and it is described somewhere (I admit that I still didn't find the time to read in the Mastering XPages ed.2 book yet 
).
Can you give me a hint what was happening here? I always try to avoid the variable resolver due to performance/memory issues so I'd be interested what was going wrong here.
UPDATE
Yesterday I immediately received an answer:
https://twitter.com/Gidgerby/status/474615613789589504