TRDR-73 Restrict Clojure symbols for array class notation

Author: NoahTheDuke

src/main/clojure/clojure/tools/reader/impl/commons.clj

@@ -107,11 +107,14 @@
         (let [ns-idx (inc ns-idx)]
           (when-not (== ns-idx (count token))
             (let [sym (subs token ns-idx)]
-              (when (and (not (numeric? (nth sym 0)))
-                         (not (= "" sym))
-                         (not (.endsWith ns ":"))
-                         (or (= sym "/")
-                             (== -1 (.indexOf sym "/"))))
+              (cond
+                (re-matches #"[1-9]" sym)
+                [ns sym]
+                (and (not (numeric? (nth sym 0)))
+                     (not (= "" sym))
+                     (not (.endsWith ns ":"))
+                     (or (= sym "/")
+                         (== -1 (.indexOf sym "/"))))
                 [ns sym]))))
         (when (or (= token "/")
                   (== -1 (.indexOf token "/")))

src/test/clojure/clojure/tools/reader_test.clj

@@ -199,3 +199,38 @@
                           ["[a\rb]" "[a\r b]" "[a \rb]"])]
     (doseq [pairs (partition 2 1 read-vals)]
       (is (= (first pairs) (second pairs))))))
+
+(deftest read-symbol
+  (is (= 'foo (read-string "foo")))
+  (is (= 'foo/bar (read-string "foo/bar")))
+  (is (= '*+!-_? (read-string "*+!-_?")))
+  (is (= 'abc:def:ghi (read-string "abc:def:ghi")))
+  (is (= 'abc.def/ghi (read-string "abc.def/ghi")))
+  (is (= 'abc/def.ghi (read-string "abc/def.ghi")))
+  (is (= 'abc:def/ghi:jkl.mno (read-string "abc:def/ghi:jkl.mno")))
+  (is (instance? clojure.lang.Symbol (read-string "alphabet")))
+  (is (= "foo//" (str (read-string "foo//"))))
+  (is (java.lang.Double/isNaN ^double (read-string "##NaN")))
+  (is (java.lang.Double/isInfinite ^double (read-string "##Inf")))
+  (is (java.lang.Double/isInfinite ^double (read-string "##-Inf")))
+  (testing "Correct array class symbols"
+    (doseq [n (range 1 10)
+            :let [sym (str "String/" n)
+                  qsym (str "java.lang.String/" n)]]
+      (let [rsym (read-string sym)
+            rqsym (read-string qsym)]
+        (is (= ((juxt namespace name) rsym)
+               ["String" (str n)]))
+        (is (= ((juxt namespace name) rqsym)
+               ["java.lang.String" (str n)])))))
+  (testing "Correct prim array symbols"
+    (doseq [prim ["int" "long" "boolean" "byte" "char" "double" "float" "short"]]
+      (doseq [n (range 1 10)
+              :let [sym (str prim "/" n)]]
+        (let [rsym (read-string sym)]
+          (is (= ((juxt namespace name) rsym)
+                 [prim (str n)]))))))
+  (testing "Incorrect Array class symbols"
+    (doseq [suffix ["" "0" "11" "1a"]
+            :let [sym (str "String/" suffix)]]
+      (is (thrown? clojure.lang.ExceptionInfo (read-string sym)) sym))))