In http://jira.codehaus.org/browse/JRUBY-6237 it is noted that 1.9.3 (but not 1.9.2) supports
def f(x); x; end
a = b = f 1
as syntactically valid (and both a and b will be assigned f(1), naturally).
There should be a spec for this case, but I wasn't sure where it should go.
The spec would go in method call specs under language.
Unfortunately, I have to now change the language stuff to support separate syntax in 1.9 versions. Which I'm not at all happy about.
In other words, there's no way to add this spec right now.