Bug 811784: Account for subscripts when figuring out what object to stick properties on. r=mrbkap

js/xpconnect/loader/mozJSComponentLoader.cpp

@@ -625,6 +625,16 @@ mozJSComponentLoader::FindTargetObject(JSContext* aCx,
     return NS_OK;
 }
 
+void
+mozJSComponentLoader::NoteSubScript(JSScript* aScript, JSObject* aThisObject)
+{
+  if (!mInitialized && NS_FAILED(ReallyInit())) {
+      MOZ_NOT_REACHED();
+  }
+
+  mThisObjects.Put(aScript, aThisObject);
+}
+
 // Some stack based classes for cleaning up on early return
 #ifdef HAVE_PR_MEMMAP
 class FileAutoCloser

js/xpconnect/loader/mozJSComponentLoader.h

@@ -54,6 +54,8 @@ class mozJSComponentLoader : public mozilla::ModuleLoader,
 
     static mozJSComponentLoader* Get() { return sSelf; }
 
+    void NoteSubScript(JSScript* aScript, JSObject* aThisObject);
+
  protected:
     static mozJSComponentLoader* sSelf;
 

js/xpconnect/loader/mozJSSubScriptLoader.cpp

@@ -31,6 +31,7 @@
 
 #include "mozilla/scache/StartupCache.h"
 #include "mozilla/scache/StartupCacheUtils.h"
+#include "mozilla/Preferences.h"
 
 using namespace mozilla::scache;
 
@@ -77,12 +78,16 @@ nsresult
 mozJSSubScriptLoader::ReadScript(nsIURI *uri, JSContext *cx, JSObject *target_obj,
                                  const nsAString& charset, const char *uriStr,
                                  nsIIOService *serv, nsIPrincipal *principal,
-                                 JSScript **scriptp)
+                                 bool reuseGlobal, JSScript **scriptp,
+                                 JSFunction **functionp)
 {
     nsCOMPtr<nsIChannel>     chan;
     nsCOMPtr<nsIInputStream> instream;
     JSErrorReporter  er;
 
+    *scriptp = nullptr;
+    *functionp = nullptr;
+
     nsresult rv;
     // Instead of calling NS_OpenURI, we create the channel ourselves and call
     // SetContentType, to avoid expensive MIME type lookups (bug 632490).
@@ -130,13 +135,27 @@ mozJSSubScriptLoader::ReadScript(nsIURI *uri, JSContext *cx, JSObject *target_ob
             return ReportError(cx, LOAD_ERROR_BADCHARSET);
         }
 
-        *scriptp = JS::Compile(cx, target_obj_root, options,
+        if (!reuseGlobal) {
-                               reinterpret_cast<const jschar*>(script.get()), script.Length());
+            *scriptp = JS::Compile(cx, target_obj_root, options,
+                                   reinterpret_cast<const jschar*>(script.get()),
+                                   script.Length());
+        } else {
+            *functionp = JS::CompileFunction(cx, target_obj_root, options,
+                                             nullptr, 0, nullptr,
+                                             reinterpret_cast<const jschar*>(script.get()),
+                                             script.Length());
+        }
     } else {
         // We only use LAZY_SOURCE when no special encoding is specified because
         // the lazy source loader doesn't know the encoding.
-        options.setSourcePolicy(JS::CompileOptions::LAZY_SOURCE);
+        if (!reuseGlobal) {
-        *scriptp = JS::Compile(cx, target_obj_root, options, buf.get(), len);
+            options.setSourcePolicy(JS::CompileOptions::LAZY_SOURCE);
+            *scriptp = JS::Compile(cx, target_obj_root, options, buf.get(), len);
+        } else {
+            *functionp = JS::CompileFunction(cx, target_obj_root, options,
+                                             nullptr, 0, nullptr, buf.get(),
+                                             len);
+        }
     }
 
     /* repent for our evil deeds */
@@ -180,16 +199,20 @@ mozJSSubScriptLoader::LoadSubScript(const nsAString& url,
     JSAutoRequest ar(cx);
 
     JSObject* targetObj;
-    if (!JS_ValueToObject(cx, target, &targetObj))
+    mozJSComponentLoader* loader = mozJSComponentLoader::Get();
+    rv = loader->FindTargetObject(cx, &targetObj);
+    NS_ENSURE_SUCCESS(rv, rv);
+
+    bool reusingGlobal = !JS_IsGlobalObject(targetObj);
+
+    // We base reusingGlobal off of what the loader told us, but we may not
+    // actually be using that object.
+    JSObject* passedObj;
+    if (!JS_ValueToObject(cx, target, &passedObj))
         return NS_ERROR_ILLEGAL_VALUE;
 
-
+    if (passedObj)
-    if (!targetObj) {
+        targetObj = passedObj;
-        // If the user didn't provide an object to eval onto, find one.
-        mozJSComponentLoader* loader = mozJSComponentLoader::Get();
-        rv = loader->FindTargetObject(cx, &targetObj);
-        NS_ENSURE_SUCCESS(rv, rv);
-    }
 
     // Remember an object out of the calling compartment so that we
     // can properly wrap the result later.
@@ -274,20 +297,32 @@ mozJSSubScriptLoader::LoadSubScript(const nsAString& url,
     cachePath.AppendPrintf("jssubloader/%d", version);
     PathifyURI(uri, cachePath);
 
+    JSFunction* function = nullptr;
     script = nullptr;
     if (cache)
         rv = ReadCachedScript(cache, cachePath, cx, mSystemPrincipal, &script);
     if (!script) {
         rv = ReadScript(uri, cx, targetObj, charset,
                         static_cast<const char*>(uriStr.get()), serv,
-                        principal, &script);
+                        principal, reusingGlobal, &script, &function);
-        writeScript = true;
+        writeScript = !!script;
     }
 
-    if (NS_FAILED(rv) || !script)
+    if (NS_FAILED(rv) || (!script && !function))
         return rv;
 
-    bool ok = JS_ExecuteScriptVersion(cx, targetObj, script, retval, version);
+    if (function) {
+        script = JS_GetFunctionScript(cx, function);
+    }
+
+    loader->NoteSubScript(script, targetObj);
+
+    bool ok = false;
+    if (function) {
+        ok = JS_CallFunction(cx, targetObj, function, 0, nullptr, retval);
+    } else {
+        ok = JS_ExecuteScriptVersion(cx, targetObj, script, retval, version);
+    }
 
     if (ok) {
         JSAutoCompartment rac(cx, result_obj);

js/xpconnect/loader/mozJSSubScriptLoader.h

@@ -33,7 +33,8 @@ private:
     nsresult ReadScript(nsIURI *uri, JSContext *cx, JSObject *target_obj,
                         const nsAString& charset, const char *uriStr,
                         nsIIOService *serv, nsIPrincipal *principal,
-                        JSScript **scriptp);
+                        bool reuseGlobal, JSScript **scriptp,
+                        JSFunction **functionp);
 
     nsCOMPtr<nsIPrincipal> mSystemPrincipal;
 };