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[CLJ-1058] StackOverflowError on exception in reducef for PersistentHashMap fold Created: 02/Sep/12  Updated: 12/Apr/13

Status: Open
Project: Clojure
Component/s: None
Affects Version/s: Release 1.5
Fix Version/s: Release 1.6

Type: Defect Priority: Major
Reporter: Tom Jack Assignee: Unassigned
Resolution: Unresolved Votes: 0
Labels: None
Environment:

Clojure 1.5.0-alpha4, Sun Java 1.6.0_35, with [org.codehaus.jsr166-mirror/jsr166y "1.7.0"]


Approval: Vetted

 Description   

If reducef throws an exception, the PHM fold code can descend into an infinite loop, causing a stack overflow which masks the problem. This situation is commented "aargh" in PersistentHashMap.java line 444 (as of 412a51d).

To reproduce:

user> (require '[clojure.core.reducers :as r])
nil
user> (r/fold (fn ([]) ([ret k v] (+ 3 "foo") ret)) (into {} (map (juxt identity identity) (range 10000))))
;; boom

This results in a stack like: https://raw.github.com/gist/3bab917287a7fd635a84/f38bfe3e270556e467f3fc02062af7ea10781390/gistfile1.txt



 Comments   
Comment by Timothy Baldridge [ 30/Nov/12 3:40 PM ]

Verified as a bug.

Generated at Fri May 24 20:17:51 CDT 2013 using JIRA 4.4#649-r158309.