servo: Merge #2947 - Implement the delete proxy trap (fixes #2213); r=jdm (from Ms2ger:delete-trap)

Source-Repo: https://github.com/servo/servo
Source-Revision: 4da88f0ecc92149034f5bba70d5105f995693b1e

servo/src/components/script/dom/bindings/codegen/CodegenRust.py

@@ -2061,7 +2061,7 @@ let traps = ProxyTraps {
   getOwnPropertyDescriptor: Some(getOwnPropertyDescriptor),
   defineProperty: Some(defineProperty),
   getOwnPropertyNames: ptr::null(),
-  delete_: None,
+  delete_: Some(delete_),
   enumerate: ptr::null(),
 
   has: None,
@@ -4541,7 +4541,7 @@ class CGBindingRoot(CGThing):
             'dom::bindings::proxyhandler',
             'dom::bindings::proxyhandler::{_obj_toString, defineProperty}',
             'dom::bindings::proxyhandler::{FillPropertyDescriptor, GetExpandoObject}',
-            'dom::bindings::proxyhandler::{getPropertyDescriptor}',
+            'dom::bindings::proxyhandler::{delete_, getPropertyDescriptor}',
             'dom::bindings::str::ByteString',
             'page::JSPageInfo',
             'libc',

servo/src/components/script/dom/bindings/proxyhandler.rs

@@ -10,7 +10,8 @@ use js::jsapi::{JS_GetPropertyDescriptorById, JS_NewUCString, JS_malloc, JS_free
 use js::jsapi::{JSBool, JS_DefinePropertyById, JS_NewObjectWithGivenProto};
 use js::jsapi::{JS_ReportErrorFlagsAndNumber, JS_StrictPropertyStub};
 use js::jsapi::{JSREPORT_WARNING, JSREPORT_STRICT, JSREPORT_STRICT_MODE_ERROR};
-use js::jsval::ObjectValue;
+use js::jsapi::JS_DeletePropertyById2;
+use js::jsval::{UndefinedValue, ObjectValue};
 use js::glue::GetProxyExtra;
 use js::glue::{GetObjectProto, GetObjectParent, SetProxyExtra, GetProxyHandler};
 use js::glue::InvokeGetOwnPropertyDescriptor;
@@ -78,6 +79,24 @@ pub extern fn defineProperty(cx: *mut JSContext, proxy: *mut JSObject, id: jsid,
     defineProperty_(cx, proxy, id, desc)
 }
 
+pub extern fn delete_(cx: *mut JSContext, proxy: *mut JSObject, id: jsid,
+                      bp: *mut bool) -> JSBool {
+    unsafe {
+        let expando = EnsureExpandoObject(cx, proxy);
+        if expando.is_null() {
+            return 0;
+        }
+
+        let mut value = UndefinedValue();
+        if JS_DeletePropertyById2(cx, expando, id, &mut value) == 0 {
+            return 0;
+        }
+
+        *bp = value.to_boolean();
+        return 1;
+    }
+}
+
 pub fn _obj_toString(cx: *mut JSContext, className: *libc::c_char) -> *mut JSString {
   unsafe {
     let name = str::raw::from_c_str(className);