From 287ca21a651803ce87347ba584ce93908cd8a9e6 Mon Sep 17 00:00:00 2001 From: janekptacijarabaci Date: Sat, 14 Apr 2018 22:20:43 +0200 Subject: moebius#242: XPCOM: exportFunction() - fix wrong .length attribute https://github.com/MoonchildProductions/moebius/pull/243 --- js/xpconnect/src/ExportHelpers.cpp | 11 ++++++++++- js/xpconnect/tests/unit/test_exportFunction.js | 3 +++ 2 files changed, 13 insertions(+), 1 deletion(-) diff --git a/js/xpconnect/src/ExportHelpers.cpp b/js/xpconnect/src/ExportHelpers.cpp index 3dbf83e3b..e574e708c 100644 --- a/js/xpconnect/src/ExportHelpers.cpp +++ b/js/xpconnect/src/ExportHelpers.cpp @@ -329,11 +329,20 @@ NewFunctionForwarder(JSContext* cx, HandleId idArg, HandleObject callable, if (id == JSID_VOIDHANDLE) id = GetJSIDByIndex(cx, XPCJSContext::IDX_EMPTYSTRING); + // If our callable is a (possibly wrapped) function, we can give + // the exported thing the right number of args. + unsigned nargs = 0; + RootedObject unwrapped(cx, js::UncheckedUnwrap(callable)); + if (unwrapped) { + if (JSFunction* fun = JS_GetObjectFunction(unwrapped)) + nargs = JS_GetFunctionArity(fun); + } + // We have no way of knowing whether the underlying function wants to be a // constructor or not, so we just mark all forwarders as constructors, and // let the underlying function throw for construct calls if it wants. JSFunction* fun = js::NewFunctionByIdWithReserved(cx, FunctionForwarder, - 0, JSFUN_CONSTRUCTOR, id); + nargs, JSFUN_CONSTRUCTOR, id); if (!fun) return false; diff --git a/js/xpconnect/tests/unit/test_exportFunction.js b/js/xpconnect/tests/unit/test_exportFunction.js index 830816342..9e1bf2082 100644 --- a/js/xpconnect/tests/unit/test_exportFunction.js +++ b/js/xpconnect/tests/unit/test_exportFunction.js @@ -10,12 +10,14 @@ function run_test() { epsb.do_check_true = do_check_true; epsb.do_check_eq = do_check_eq; subsb.do_check_true = do_check_true; + subsb.do_check_eq = do_check_eq; // Exporting should work if prinicipal of the source sandbox // subsumes the principal of the target sandbox. Cu.evalInSandbox("(" + function() { var wasCalled = false; this.funToExport = function(expectedThis, a, obj, native, mixed, callback) { + do_check_eq(arguments.callee.length, 6); do_check_eq(a, 42); do_check_eq(obj, subsb.tobecloned); do_check_eq(obj.cloned, "cloned"); @@ -53,6 +55,7 @@ function run_test() { invokedCallback = false; callback = function() { invokedCallback = true; }; imported(this, 42, tobecloned, native, mixed, callback); + do_check_eq(imported.length, 6); do_check_true(invokedCallback); }.toSource() + ")()", subsb); -- cgit v1.2.3