diff -r 000000000000 -r 6474c204b198 js/src/jit-test/tests/debug/Source-introductionScript-03.js
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/js/src/jit-test/tests/debug/Source-introductionScript-03.js	Wed Dec 31 06:09:35 2014 +0100
@@ -0,0 +1,32 @@
+// We don't record introduction scripts in a different global from the
+// introduced script, even if they're both debuggees.
+
+var dbg = new Debugger;
+
+var g1 = newGlobal();
+g1.g1 = g1;
+var g1DO = dbg.addDebuggee(g1);
+
+var g2 = newGlobal();
+g2.g1 = g1;
+
+var log = '';
+dbg.onDebuggerStatement = function (frame) {
+  log += 'd';
+  assertEq(frame.script.source.introductionScript, undefined);
+  assertEq(frame.script.source.introductionOffset, undefined);
+};
+
+g2.eval('g1.eval("debugger;");');
+assertEq(log, 'd');
+
+// Just for sanity: when it's not cross-global, we do note the introducer.
+log = '';
+dbg.onDebuggerStatement = function (frame) {
+  log += 'd';
+  assertEq(frame.script.source.introductionScript instanceof Debugger.Script, true);
+  assertEq(typeof frame.script.source.introductionOffset, "number");
+};
+// Exactly as above, but with g1 instead of g2.
+g1.eval('g1.eval("debugger;");');
+assertEq(log, 'd');