Drop thenable coercion cache

R=dslomov@chromium.org
BUG=372788
LOG=Y

Review URL: https://codereview.chromium.org/281753004

git-svn-id: https://v8.googlecode.com/svn/branches/bleeding_edge@21301 ce2b1a6d-e550-0410-aec6-3dcde31c8c00

src/promise.js

@@ -204,24 +204,16 @@ function PromiseThen(onResolve, onReject) {
   );
 }
 
-PromiseCoerce.table = new $WeakMap;
-
 function PromiseCoerce(constructor, x) {
   if (!IsPromise(x) && IS_SPEC_OBJECT(x)) {
     var then;
     try {
       then = x.then;
     } catch(r) {
-      var promise = %_CallFunction(constructor, r, PromiseRejected);
-      PromiseCoerce.table.set(x, promise);
-      return promise;
+      return %_CallFunction(constructor, r, PromiseRejected);
     }
-    if (typeof then === 'function') {
-      if (PromiseCoerce.table.has(x)) {
-        return PromiseCoerce.table.get(x);
-      } else {
+    if (IS_SPEC_FUNCTION(then)) {
       var deferred = %_CallFunction(constructor, PromiseDeferred);
-        PromiseCoerce.table.set(x, deferred.promise);
       try {
         %_CallFunction(x, deferred.resolve, deferred.reject, then);
       } catch(r) {
@@ -230,7 +222,6 @@ function PromiseCoerce(constructor, x) {
       return deferred.promise;
     }
   }
-  }
   return x;
 }
 

test/mjsunit/es6/regress/regress-cr372788.js

+// Copyright 2014 the V8 project authors. All rights reserved.
+// Redistribution and use in source and binary forms, with or without
+// modification, are permitted provided that the following conditions are
+// met:
+//
+//     * Redistributions of source code must retain the above copyright
+//       notice, this list of conditions and the following disclaimer.
+//     * Redistributions in binary form must reproduce the above
+//       copyright notice, this list of conditions and the following
+//       disclaimer in the documentation and/or other materials provided
+//       with the distribution.
+//     * Neither the name of Google Inc. nor the names of its
+//       contributors may be used to endorse or promote products derived
+//       from this software without specific prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+// Flags: --allow-natives-syntax
+
+var x = 0;
+var y = 0;
+
+var thenable = { then: function(f) { x++; f(); } };
+
+for (var i = 0; i < 3; ++i) {
+  Promise.resolve(thenable).then(function() { x++; y++; });
+}
+assertEquals(0, x);
+
+(function check() {
+  Promise.resolve().chain(function() {
+    // Delay check until all handlers have run.
+    if (y < 3) check(); else assertEquals(6, x);
+  }).catch(function(e) { %AbortJS("FAILURE: " + e) });
+})();