version check fails when clojure is a managed dependency

[pcarlisle]

As of Leiningen 2.7.0 it is possible to leave out version numbers under the :dependencies key of a project map, and list them under the :managed-dependencies key instead [Managed Dependencies].

If the dependency on clojure is listed this way, the repl fails to start with a stack trace.

With this project.clj:

(defproject test "0.1.0-SNAPSHOT"
  :dependencies [[org.clojure/clojure]]
  :managed-dependencies [[org.clojure/clojure "1.8.0"]]
  :plugins [[cider/cider-nrepl "0.14.0-SNAPSHOT"]
            [refactor-nrepl "2.3.0-SNAPSHOT"]])

test:% lein repl
java.lang.NullPointerException: null
 at java.util.regex.Matcher.getTextLength (Matcher.java:1283)
    java.util.regex.Matcher.reset (Matcher.java:309)
    java.util.regex.Matcher.<init> (Matcher.java:229)
    java.util.regex.Pattern.matcher (Pattern.java:1093)
    java.util.regex.Pattern.split (Pattern.java:1206)
    clojure.string$split.invokeStatic (string.clj:226)
    clojure.string$split.invoke (string.clj:219)
    leiningen.core.main$version_satisfies_QMARK_.invokeStatic (main.clj:340)
    leiningen.core.main$version_satisfies_QMARK_.invoke (main.clj:339)
    refactor_nrepl.plugin$version_ok_QMARK_$fn__12615.invoke (plugin.clj:15)
    clojure.core$some.invokeStatic (core.clj:2592)
    clojure.core$some.invoke (core.clj:2583)
    refactor_nrepl.plugin$version_ok_QMARK_.invokeStatic (plugin.clj:13)
    refactor_nrepl.plugin$version_ok_QMARK_.invoke (plugin.clj:10)
    refactor_nrepl.plugin$external_dependencies_ok_QMARK_$fn__12622.invoke (plugin.clj:23)
    clojure.core.protocols$iter_reduce.invokeStatic (protocols.clj:49)
    clojure.core.protocols$fn__6742.invokeStatic (protocols.clj:75)
    clojure.core.protocols/fn (protocols.clj:75)
    clojure.core.protocols$fn__6684$G__6679__6697.invoke (protocols.clj:13)
    clojure.core$reduce.invokeStatic (core.clj:6545)
    clojure.core$reduce.invoke (core.clj:6527)
    refactor_nrepl.plugin$external_dependencies_ok_QMARK_.invokeStatic (plugin.clj:21)
    refactor_nrepl.plugin$external_dependencies_ok_QMARK_.invoke (plugin.clj:19)
    refactor_nrepl.plugin$middleware.invokeStatic (plugin.clj:29)
    refactor_nrepl.plugin$middleware.invoke (plugin.clj:27)
    clojure.lang.Var.invoke (Var.java:379)
    leiningen.core.project$apply_middleware.invokeStatic (project.clj:750)
    leiningen.core.project$apply_middleware.invoke (project.clj:743)
    clojure.core.protocols$naive_seq_reduce.invokeStatic (protocols.clj:62)
    clojure.core.protocols$interface_or_naive_reduce.invokeStatic (protocols.clj:72)
    clojure.core.protocols$fn__6755.invokeStatic (protocols.clj:168)
    clojure.core.protocols/fn (protocols.clj:124)
    clojure.core.protocols$fn__6710$G__6705__6719.invoke (protocols.clj:19)
    clojure.core.protocols$seq_reduce.invokeStatic (protocols.clj:31)
    clojure.core.protocols$fn__6738.invokeStatic (protocols.clj:75)
    clojure.core.protocols/fn (protocols.clj:75)
    clojure.core.protocols$fn__6684$G__6679__6697.invoke (protocols.clj:13)
    clojure.core$reduce.invokeStatic (core.clj:6545)
    clojure.core$reduce.invoke (core.clj:6527)
    leiningen.core.project$apply_middleware.invokeStatic (project.clj:745)
    leiningen.core.project$apply_middleware.invoke (project.clj:743)
    leiningen.core.project$activate_middleware.invokeStatic (project.clj:777)
    leiningen.core.project$activate_middleware.invoke (project.clj:773)
    leiningen.core.project$init_project.invokeStatic (project.clj:902)
    leiningen.core.project$init_project.invoke (project.clj:892)
    leiningen.core.project$read.invokeStatic (project.clj:973)
    leiningen.core.project$read.invoke (project.clj:970)
    leiningen.core.project$read.invokeStatic (project.clj:974)
    leiningen.core.project$read.invoke (project.clj:970)
    leiningen.core.main$_main$fn__5998.invoke (main.clj:397)
    leiningen.core.main$_main.invokeStatic (main.clj:394)
    leiningen.core.main$_main.doInvoke (main.clj:391)
    clojure.lang.RestFn.invoke (RestFn.java:408)
    clojure.lang.Var.invoke (Var.java:379)
    clojure.lang.AFn.applyToHelper (AFn.java:154)
    clojure.lang.Var.applyTo (Var.java:700)
    clojure.core$apply.invokeStatic (core.clj:646)
    clojure.main$main_opt.invokeStatic (main.clj:314)
    clojure.main$main_opt.invoke (main.clj:310)
    clojure.main$main.invokeStatic (main.clj:421)
    clojure.main$main.doInvoke (main.clj:384)
    clojure.lang.RestFn.invoke (RestFn.java:436)
    clojure.lang.Var.invoke (Var.java:388)
    clojure.lang.AFn.applyToHelper (AFn.java:160)
    clojure.lang.Var.applyTo (Var.java:700)
    clojure.main.main (main.java:37)

This starts normally if refactor-nrepl is removed. This doesn't fail in cider-nrepl because it has a special case for the clojure dependency being present with a nil version.

Environment & Version information

clj-refactor.el and refactor-nrepl version information

"clj-refactor 2.3.0-SNAPSHOT (package: 20161005.344), refactor-nrepl 2.3.0-SNAPSHOT"

CIDER version information

;; CIDER 0.14.0snapshot (package: 20161006.431), nREPL 0.2.12
;; Clojure 1.7.0, Java 1.8.0_92

Leiningen or Boot version

lein 2.7.1

Emacs version

25.1.1

Operating system

arch linux