1 files changed, 61 insertions, 0 deletions
diff --git a/js/src/jsapi-tests/testExternalStrings.cpp b/js/src/jsapi-tests/testExternalStrings.cpp
new file mode 100644
index 000000000..9aca388b3
--- /dev/null
+++ b/js/src/jsapi-tests/testExternalStrings.cpp
@@ -0,0 +1,61 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#include "mozilla/ArrayUtils.h"
+#include "mozilla/PodOperations.h"
+
+#include "jsapi-tests/tests.h"
+
+using mozilla::ArrayLength;
+using mozilla::PodEqual;
+
+static const char16_t arr[] = {
+    'h', 'i', ',', 'd', 'o', 'n', '\'', 't', ' ', 'd', 'e', 'l', 'e', 't', 'e', ' ', 'm', 'e', '\0'
+};
+static const size_t arrlen = ArrayLength(arr) - 1;
+
+static int finalized1 = 0;
+static int finalized2 = 0;
+
+static void
+finalize_str(JS::Zone* zone, const JSStringFinalizer* fin, char16_t* chars);
+
+static const JSStringFinalizer finalizer1 = { finalize_str };
+static const JSStringFinalizer finalizer2 = { finalize_str };
+
+static void
+finalize_str(JS::Zone* zone, const JSStringFinalizer* fin, char16_t* chars)
+{
+    if (chars && PodEqual(const_cast<const char16_t*>(chars), arr, arrlen)) {
+        if (fin == &finalizer1) {
+            ++finalized1;
+        } else if (fin == &finalizer2) {
+            ++finalized2;
+        }
+    }
+}
+
+BEGIN_TEST(testExternalStrings)
+{
+    const unsigned N = 1000;
+
+    for (unsigned i = 0; i < N; ++i) {
+        CHECK(JS_NewExternalString(cx, arr, arrlen, &finalizer1));
+        CHECK(JS_NewExternalString(cx, arr, arrlen, &finalizer2));
+    }
+
+    // clear that newborn root
+    JS_NewUCStringCopyN(cx, arr, arrlen);
+
+    JS_GC(cx);
+
+    // a generous fudge factor to account for strings rooted by conservative gc
+    const unsigned epsilon = 10;
+
+    CHECK((N - finalized1) < epsilon);
+    CHECK((N - finalized2) < epsilon);
+
+    return true;
+}
+END_TEST(testExternalStrings)