"cake versions" with no argument throws null exception

[rosejn]

This patch fixes the error and prints a usage message, but a more general solution for all commands might be better.

diff --git a/src/cake/tasks/clojars.clj b/src/cake/tasks/clojars.clj
index f385d74..5e9e71b 100644
--- a/src/cake/tasks/clojars.clj
+++ b/src/cake/tasks/clojars.clj
@@ -50,14 +50,16 @@
     (println "\n\n")))

 (defn clojars-versions [library-name]
-  (let [response (http-get-text-seq clojars-all-jars-url)]
-    (println "\n\nAvailable versions for library: " library-name)
-    (println "--------------------------------------------------------------------------------")
-    (doseq [entry (filter #(= (first %) (symbol library-name))
-                         (for [line response]
-                           (read-string line)))]
-      (println "  " (first entry) "  " (second entry)))
-    (println "\n\n")))
+  (if (nil? library-name)
+    (println "No library specified.\n\tUsage: cake versions <library-name>")
+    (let [response (http-get-text-seq clojars-all-jars-url)]
+      (println "\n\nAvailable versions for library: " library-name)
+      (println "--------------------------------------------------------------------------------")
+      (doseq [entry (filter #(= (first %) (symbol library-name))
+                            (for [line response]
+                              (read-string line)))]
+        (println "  " (first entry) "  " (second entry)))
+      (println "\n\n"))))

[ninjudd]

thanks. i just checked in a fix for this for all clojars tasks