Prevent some common mistakes when calling parent constructors and destructors

2 files changed, 37 insertions, 0 deletions

diff --git a/src/embind/embind.js b/src/embind/embind.js
index 27dfa928..6f905d55 100644
--- a/src/embind/embind.js
+++ b/src/embind/embind.js
@@ -1823,6 +1823,10 @@ function __embind_create_inheriting_constructor(constructorName, wrapperType, pr
     // It's a little nasty that we're modifying the wrapper prototype here.
 
     wrapperPrototype.__construct = function __construct() {
+        if (this === wrapperPrototype) {
+            throwBindingError("Pass correct 'this' to __construct");
+        }
+
         var inner = baseConstructor.__$implement.apply(
             undefined,
             [this].concat(arraySlice.call(arguments)));
@@ -1835,6 +1839,10 @@ function __embind_create_inheriting_constructor(constructorName, wrapperType, pr
     };
 
     wrapperPrototype.__destruct = function __destruct() {
+        if (this === wrapperPrototype) {
+            throwBindingError("Pass correct 'this' to __destruct");
+        }
+
         unregisterInheritedInstance(registeredClass, this.$$.ptr);
     };
 
diff --git a/tests/embind/embind.test.js b/tests/embind/embind.test.js
index bc0a6154..067b3f60 100644
--- a/tests/embind/embind.test.js
+++ b/tests/embind/embind.test.js
@@ -1800,6 +1800,35 @@ module({
             rv.delete();
         });
 
+        test("can instantiate two wrappers with constructors", function() {
+            var parent = cm.HeldAbstractClass;
+            var C = parent.extend("C", {
+                __construct: function() {
+                    this.__parent.__construct.call(this);
+                },
+                method: function() {
+                }
+            });
+            var a = new C;
+            var b = new C;
+            a.delete();
+            b.delete();
+        });
+
+        test("incorrectly calling parent is an error", function() {
+            var parent = cm.HeldAbstractClass;
+            var C = parent.extend("C", {
+                __construct: function() {
+                    this.__parent.__construct();
+                },
+                method: function() {
+                }
+            });
+            assert.throws(cm.BindingError, function() {
+                new C;
+            });
+        });
+
         test("deleteLater() works for JavaScript implementations", function() {
             var parent = cm.HeldAbstractClass;
             var C = parent.extend("C", {