Details
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Type:
Defect
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Status:
Closed
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Priority:
Major
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Resolution: Completed
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Affects Version/s: Release 1.4, Release 1.5
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Fix Version/s: Release 1.5
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Component/s: None
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Labels:None
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Patch:Code
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Approval:Ok
Description
A number of vars from clojure.repl, clojure.java.javadoc, and clojure.pprint are unconditionally referred into *ns* by clojure.main/repl. This is fine when it is being used e.g. as the primary driver of a terminal-bound Clojure REPL, but other usages can end up bringing those utility vars into namespaces other than 'user. This can cause problems if clojure.main/repl is used to drive a REPL within namespaces that already have referred or interned vars with the same names as those utility vars, e.g.:
$ java -jar ~/.m2/repository/org/clojure/clojure/1.5.0-alpha6/clojure-1.5.0-alpha6.jar Clojure 1.5.0-alpha6 user=> (ns foo) nil foo=> (defn pp [] "hi!") #'foo/pp foo=> (pp) "hi!" foo=> (clojure.main/repl) foo=> (pp) nil nil foo=> (defn pp [] "whoops") CompilerException java.lang.IllegalStateException: pp already refers to: #'clojure.pprint/pp in namespace: foo, compiling:(NO_SOURCE_PATH:7:1)
Worse, nREPL uses clojure.main/repl (in large part to maximize the consistency of REPL behaviour across different Clojure versions), where each user expression is evaluated through a separate clojure.main/repl invocation. This leads to the same problems as above, but for every nREPL user, session, and expression (reported @ NREPL-31).
A simple fix for this is to perform these refers only if *ns* is 'user (which, AFAICT, was the only intended effect of CLJ-310, CLJ-454, and https://github.com/clojure/clojure/commit/04764db, the changes that added these automatic implicit refers to clojure.main/repl).
Patch attached to only refer in the utility vars if in the user namespace.