From 02efc70ce2dda09fa5c2db47593ec30b632b1f97 Mon Sep 17 00:00:00 2001
From: Jason Orendorff <jorendorff@mozilla.com>
Date: Thu, 11 Aug 2011 15:50:04 -0500
Subject: [PATCH] Fix Frame.arguments bug noticed by luke in bug 672829 comment
 69.

---
 .../tests/debug/Frame-arguments-07.js         | 23 +++++++++++++++++++
 js/src/vm/Debugger.cpp                        |  2 +-
 2 files changed, 24 insertions(+), 1 deletion(-)
 create mode 100644 js/src/jit-test/tests/debug/Frame-arguments-07.js

diff --git a/js/src/jit-test/tests/debug/Frame-arguments-07.js b/js/src/jit-test/tests/debug/Frame-arguments-07.js
new file mode 100644
index 00000000000..3e7e902deb1
--- /dev/null
+++ b/js/src/jit-test/tests/debug/Frame-arguments-07.js
@@ -0,0 +1,23 @@
+// When argument[x] is assigned, where x > callee.length, frame.arguments reflects the change.
+
+var g = newGlobal('new-compartment');
+g.eval("function f(a, b) {\n" +
+       "    for (var i = 0; i < arguments.length; i++)\n" +
+       "        arguments[i] = i;\n" +
+       "    debugger;\n" +
+       "}\n");
+
+var dbg = Debugger(g);
+var hits = 0;
+dbg.onDebuggerStatement = function (frame) {
+    var argc = frame.eval("arguments.length").return;
+    var args = frame.arguments;
+    assertEq(args.length, argc);
+    for (var i = 0; i < argc; i++)
+	assertEq(args[i], i);
+    hits++;
+}
+
+g.f(9);
+g.f(9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9);
+assertEq(hits, 2);
diff --git a/js/src/vm/Debugger.cpp b/js/src/vm/Debugger.cpp
index 0599ebad0c1..4774cb4011d 100644
--- a/js/src/vm/Debugger.cpp
+++ b/js/src/vm/Debugger.cpp
@@ -2506,7 +2506,7 @@ DebuggerArguments_getArg(JSContext *cx, uintN argc, Value *vp)
      */
     JS_ASSERT(i >= 0);
     if (uintN(i) < fp->numActualArgs())
-        *vp = fp->actualArgs()[i];
+        *vp = fp->canonicalActualArg(i);
     else
         vp->setUndefined();
     return Debugger::fromChildJSObject(thisobj)->wrapDebuggeeValue(cx, vp);