3 files changed, 26 insertions, 7 deletions

diff --git a/js/src/jsfun.h b/js/src/jsfun.h
index 7da831aa2..1c7da57ec 100644
--- a/js/src/jsfun.h
+++ b/js/src/jsfun.h
@@ -460,6 +460,19 @@ class JSFunction : public js::NativeObject
         return nonLazyScript();
     }
 
+    // If this is a scripted function, returns its canonical function (the
+    // original function allocated by the frontend). Note that lazy self-hosted
+    // builtins don't have a lazy script so in that case we also return nullptr.
+    JSFunction* maybeCanonicalFunction() const {
+        if (hasScript()) {
+            return nonLazyScript()->functionNonDelazifying();
+        }
+        if (isInterpretedLazy() && !isSelfHostedBuiltin()) {
+            return lazyScript()->functionNonDelazifying();
+        }
+        return nullptr;
+    }
+
     // The state of a JSFunction whose script errored out during bytecode
     // compilation. Such JSFunctions are only reachable via GC iteration and
     // not from script.
diff --git a/js/src/vm/ObjectGroup.cpp b/js/src/vm/ObjectGroup.cpp
index d6a8fcaa4..1fbf8976b 100644
--- a/js/src/vm/ObjectGroup.cpp
+++ b/js/src/vm/ObjectGroup.cpp
@@ -496,12 +496,7 @@ ObjectGroup::defaultNewGroup(ExclusiveContext* cx, const Class* clasp,
 
             // Canonicalize new functions to use the original one associated with its script.
             JSFunction* fun = &associated->as<JSFunction>();
-            if (fun->hasScript())
-                associated = fun->nonLazyScript()->functionNonDelazifying();
-            else if (fun->isInterpretedLazy() && !fun->isSelfHostedBuiltin())
-                associated = fun->lazyScript()->functionNonDelazifying();
-            else
-                associated = nullptr;
+            associated = associated->as<JSFunction>().maybeCanonicalFunction();
 
             // If we have previously cleared the 'new' script information for this
             // function, don't try to construct another one.
diff --git a/js/src/vm/TypeInference.cpp b/js/src/vm/TypeInference.cpp
index c86345d9c..4775a2dea 100644
--- a/js/src/vm/TypeInference.cpp
+++ b/js/src/vm/TypeInference.cpp
@@ -3603,6 +3603,10 @@ TypeNewScript::make(JSContext* cx, ObjectGroup* group, JSFunction* fun)
     MOZ_ASSERT(!group->newScript());
     MOZ_ASSERT(!group->maybeUnboxedLayout());
 
+    // rollbackPartiallyInitializedObjects expects function_ to be
+    // canonicalized.
+    MOZ_ASSERT(fun->maybeCanonicalFunction() == fun);
+
     if (group->unknownProperties())
         return true;
 
@@ -3958,8 +3962,15 @@ TypeNewScript::rollbackPartiallyInitializedObjects(JSContext* cx, ObjectGroup* g
                 oomUnsafe.crash("rollbackPartiallyInitializedObjects");
         }
 
-        if (!iter.isConstructing() || !iter.matchCallee(cx, function))
+        if (!iter.isConstructing()) {
+            continue;
+        }
+
+        MOZ_ASSERT(iter.calleeTemplate()->maybeCanonicalFunction());
+
+        if (iter.calleeTemplate()->maybeCanonicalFunction() != function) {
             continue;
+        }
 
         // Derived class constructors initialize their this-binding later and
         // we shouldn't run the definite properties analysis on them.