[gjs: 1/4] byteArray: Add checks that object is a Uint8Array

[Cosimo Cecchi <cosimoc src gnome org>]

commit 8e6ed6ccc8769bf8782b579463ecc7692cca9c77
Author: Philip Chimento <philip chimento gmail com>
Date:   Mon Nov 12 17:37:08 2018 -0500

    byteArray: Add checks that object is a Uint8Array
    
    This avoids a crash when the wrong object is passed to the functions.
    
    Closes #219.

 gjs/byteArray.cpp                   | 12 ++++++++++++
 installed-tests/js/testByteArray.js |  6 ++++++
 2 files changed, 18 insertions(+)
---
diff --git a/gjs/byteArray.cpp b/gjs/byteArray.cpp
index 6130eb65..825e1bf8 100644
--- a/gjs/byteArray.cpp
+++ b/gjs/byteArray.cpp
@@ -50,6 +50,12 @@ static void bytes_unref_arraybuffer(void* contents, void* user_data) {
 GJS_JSAPI_RETURN_CONVENTION
 static bool to_string_impl(JSContext* context, JS::HandleObject byte_array,
                            const char* encoding, JS::MutableHandleValue rval) {
+    if (!JS_IsUint8Array(byte_array)) {
+        gjs_throw(context,
+                  "Argument to ByteArray.toString() must be a Uint8Array");
+        return false;
+    }
+
     bool encoding_is_utf8;
     uint8_t* data;
 
@@ -161,6 +167,12 @@ to_gbytes_func(JSContext *context,
                              "byteArray", &byte_array))
         return false;
 
+    if (!JS_IsUint8Array(byte_array)) {
+        gjs_throw(context,
+                  "Argument to ByteArray.toGBytes() must be a Uint8Array");
+        return false;
+    }
+
     GBytes* bytes = gjs_byte_array_get_bytes(byte_array);
     gbytes_info = g_irepository_find_by_gtype(NULL, G_TYPE_BYTES);
     ret_bytes_obj = gjs_boxed_from_c_struct(context, (GIStructInfo*)gbytes_info,
diff --git a/installed-tests/js/testByteArray.js b/installed-tests/js/testByteArray.js
index 3c537603..4bcebf8c 100644
--- a/installed-tests/js/testByteArray.js
+++ b/installed-tests/js/testByteArray.js
@@ -58,6 +58,12 @@ describe('Byte array', function () {
         expect(s).toEqual('ab');
     });
 
+    it('deals gracefully with a non Uint8Array', function () {
+        const a = [97, 98, 99, 100, 0];
+        expect(() => ByteArray.toString(a)).toThrow();
+        expect(() => ByteArray.toGBytes(a)).toThrow();
+    });
+
     describe('legacy toString() behavior', function () {
         beforeEach(function () {
             GLib.test_expect_message('Gjs', GLib.LogLevelFlags.LEVEL_WARNING,