[CLJ-1140] {:as x} destructuring with an empty list raises exception

Fri, 1 Mar 2013 09:49:21 -0600

user=> (clojure-version)
"1.4.0"
user=> (let [{:as x} '()] x)
{}

...

user=> (clojure-version)
"1.5.0-RC1"
user=> (let [{:as x} '()] x)
IllegalArgumentException No value supplied for key: null  clojure.lang.PersistentHashMap.create (PersistentHashMap.java:77)

The bug was introduced by a change[1] to support duplicate keys in map
destructuring. Using PersistentHashMap/create here introduces the above
bug, since it does not properly handle empty lists.

[1]: https://github.com/clojure/clojure/commit/93c795fe10ee5c92a36b6ec6373b3c80a31135c4

Clojure JIRA

[CLJ-1140] {:as x} destructuring with an empty list raises exception