[fix] dont mutate module names (#5231)

jruby · Jun 26, 2018 · a7c5eb9 · a7c5eb9
1 parent 4e8bb26
commit a7c5eb9
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Showing 2 changed files with 13 additions and 3 deletions.
diff --git a/core/src/main/java/org/jruby/RubyModule.java b/core/src/main/java/org/jruby/RubyModule.java
@@ -2367,9 +2367,10 @@ public RubyFixnum hash() {
     @JRubyMethod(name = "to_s", alias = "inspect")
     @Override
     public RubyString to_s() {
+        Ruby runtime = getRuntime();
         if(isSingleton()){
             IRubyObject attached = ((MetaClass) this).getAttached();
-            RubyString buffer = getRuntime().newString("#<Class:");
+            RubyString buffer = runtime.newString("#<Class:");
 
             if (attached != null) { // FIXME: figure out why we getService null sometimes
                 if (attached instanceof RubyClass || attached instanceof RubyModule) {
@@ -2378,12 +2379,12 @@ public RubyString to_s() {
                     buffer.cat19((RubyString) attached.anyToString());
                 }
             }
-            buffer.cat19(getRuntime().newString(">"));
+            buffer.cat19(runtime.newString(">"));
 
             return buffer;
         }
 
-        return rubyName();
+        return rubyName().strDup(runtime);
     }
 
     /** rb_mod_eqq

diff --git a/test/jruby/test_module.rb b/test/jruby/test_module.rb
@@ -9,6 +9,15 @@ def test_prepend_features_type_error
       Module.new.instance_eval { prepend_features(1) }
     end
   end
+
+  module XXX
+  end
+
+  def test_module_name_is_not_mutated
+    assert_false XXX.to_s.object_id != XXX.to_s.object_id
+    XXX.to_s.downcase!
+    assert_equal XXX.to_s, "XXX"
+  end
 
   module M
     C = 'public';  public_constant  :C