re-import changed deftype, see #303

Signed-off-by: Stuart Halloway <stu@thinkrelevance.com>

src/clj/clojure/core_deftype.clj

@@ -18,7 +18,6 @@
                (vector name (vec (map tag args)) (tag name)))
         cname (with-meta (symbol (str *ns* "." name)) (meta name))]
     `(do (gen-interface :name ~cname :methods ~(vec (map psig sigs)))
-         (ns-unmap (find-ns '~(ns-name *ns*)) '~name)
          (import ~cname))))
 
 ;;;;;;;;;;;;;;;;;;;;;;;;;;;; reify/deftype ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
@@ -289,7 +288,6 @@
        ~(emit-defrecord name gname (vec hinted-fields) (vec interfaces) methods)
        (defmethod print-method ~classname [o# w#]
            ((var print-defrecord) o# w#))
-       (ns-unmap (find-ns '~(ns-name *ns*)) '~name)
        (import ~classname)
        #_(defn ~name
          ([~@fields] (new ~classname ~@fields nil nil))
@@ -379,7 +377,6 @@
         fields (vec (map #(with-meta % nil) fields))]
     `(do
        ~(emit-deftype* name gname (vec hinted-fields) (vec interfaces) methods)
-       (ns-unmap (find-ns '~(ns-name *ns*)) '~name)
        (import ~classname))))
 
 

src/jvm/clojure/lang/Namespace.java

@@ -86,6 +86,30 @@ Object reference(Symbol sym, Object val){
 	throw new IllegalStateException(sym + " already refers to: " + o + " in namespace: " + name);
 }
 
+public static boolean areDifferentInstancesOfSameClassName(Class cls1, Class cls2) {
+    return (cls1 != cls2) && (cls1.getName().equals(cls2.getName()));
+}
+
+Class referenceClass(Symbol sym, Class val){
+    if(sym.ns != null)
+        {
+        throw new IllegalArgumentException("Can't intern namespace-qualified symbol");
+        }
+    IPersistentMap map = getMappings();
+    Class c = (Class) map.valAt(sym);
+    while((c == null) || (areDifferentInstancesOfSameClassName(c, val)))
+        {
+        IPersistentMap newMap = map.assoc(sym, val);
+        mappings.compareAndSet(map, newMap);
+        map = getMappings();
+        c = (Class) map.valAt(sym);
+        }
+    if(c == val)
+        return c;
+
+    throw new IllegalStateException(sym + " already refers to: " + c + " in namespace: " + name);
+}
+
 public void unmap(Symbol sym) throws Exception{
 	if(sym.ns != null)
 		{
@@ -101,7 +125,7 @@ public void unmap(Symbol sym) throws Exception{
 }
 
 public Class importClass(Symbol sym, Class c){
-	return (Class) reference(sym, c);
+	return referenceClass(sym, c);
 
 }
 

test/clojure/test_clojure/ns_libs.clj

@@ -6,7 +6,7 @@
 ;   the terms of this license.
 ;   You must not remove this notice, or any other, from this software.
 
-; Author: Frantisek Sodomka
+; Authors: Frantisek Sodomka, Stuart Halloway
 
 (ns clojure.test-clojure.ns-libs
   (:use clojure.test))
@@ -34,3 +34,40 @@
          (is (thrown? Exception (use :foo)))
          (is (thrown? Exception (use))))
 
+(deftest reimporting-deftypes
+  (let [inst1 (binding [*ns* *ns*]
+                (eval '(do (ns exporter)
+                           (defrecord ReimportMe [a])
+                           (ns importer)
+                           (import exporter.ReimportMe)
+                           (ReimportMe. 1))))
+        inst2 (binding [*ns* *ns*]
+                (eval '(do (ns exporter)
+                           (defrecord ReimportMe [a b])
+                           (ns importer)
+                           (import exporter.ReimportMe)
+                           (ReimportMe. 1 2))))]
+    (testing "you can reimport a changed class and see the changes"
+      (is (= [:a] (keys inst1)))
+      (is (= [:a :b] (keys inst2))))
+    (testing "you cannot import same local name from a different namespace"
+      (is (thrown? clojure.lang.Compiler$CompilerException
+                  #"ReimportMe already refers to: class exporter.ReimportMe in namespace: importer"
+                  (binding [*ns* *ns*]
+                    (eval '(do (ns exporter-2)
+                               (defrecord ReimportMe [a b])
+                               (ns importer)
+                               (import exporter-2.ReimportMe)
+                               (ReimportMe. 1 2)))))))))
+
+(deftest naming-types
+  (testing "you cannot use a name already referred from another namespace"
+    (is (thrown? IllegalStateException
+                 #"String already refers to: class java.lang.String"
+                 (definterface String)))
+    (is (thrown? IllegalStateException
+                 #"StringBuffer already refers to: class java.lang.StringBuffer"
+                 (deftype StringBuffer [])))
+    (is (thrown? IllegalStateException
+                 #"Integer already refers to: class java.lang.Integer"
+                 (defrecord Integer [])))))