commit 3055196eb5f1 (HEAD)
Author: Luke Wagner <luke@mozilla.com>
Date:   Sat Dec 2 12:33:29 2017 -0500

    Bug 1415291 - Baldr: factor out ToTableIndex(). r=bbouvier, a=gchang
---
 js/src/wasm/WasmJS.cpp | 18 ++++++++++++++++--
 1 file changed, 16 insertions(+), 2 deletions(-)

diff --git js/src/wasm/WasmJS.cpp js/src/wasm/WasmJS.cpp
index 1d07b0d065fe..482de9788221 100644
--- js/src/wasm/WasmJS.cpp
+++ js/src/wasm/WasmJS.cpp
@@ -1694,6 +1694,20 @@ const JSPropertySpec WasmTableObject::properties[] =
     JS_PS_END
 };
 
+static bool
+ToTableIndex(JSContext* cx, HandleValue v, const Table& table, const char* noun, uint32_t* index)
+{
+    if (!ToNonWrappingUint32(cx, v, UINT32_MAX, "Table", noun, index))
+        return false;
+
+    if (*index >= table.length()) {
+        JS_ReportErrorNumberASCII(cx, GetErrorMessage, nullptr, JSMSG_WASM_BAD_UINT32, "Table", noun);
+        return false;
+    }
+
+    return true;
+}
+
 /* static */ bool
 WasmTableObject::getImpl(JSContext* cx, const CallArgs& args)
 {
@@ -1701,7 +1715,7 @@ WasmTableObject::getImpl(JSContext* cx, const CallArgs& args)
     const Table& table = tableObj->table();
 
     uint32_t index;
-    if (!ToNonWrappingUint32(cx, args.get(0), table.length() - 1, "Table", "get index", &index))
+    if (!ToTableIndex(cx, args.get(0), table, "get index", &index))
         return false;
 
     ExternalTableElem& elem = table.externalArray()[index];
@@ -1740,7 +1754,7 @@ WasmTableObject::setImpl(JSContext* cx, const CallArgs& args)
         return false;
 
     uint32_t index;
-    if (!ToNonWrappingUint32(cx, args.get(0), table.length() - 1, "Table", "set index", &index))
+    if (!ToTableIndex(cx, args.get(0), table, "set index", &index))
         return false;
 
     RootedFunction value(cx);