diff -r 000000000000 -r 6474c204b198 js/src/jit-test/tests/debug/Frame-onStep-10.js
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/js/src/jit-test/tests/debug/Frame-onStep-10.js	Wed Dec 31 06:09:35 2014 +0100
@@ -0,0 +1,28 @@
+// Throwing and catching an error in an onStep handler shouldn't interfere
+// with throwing and catching in the debuggee.
+
+var g = newGlobal();
+g.eval("function f() { debugger; throw 'mud'; }");
+
+var dbg = Debugger(g);
+var stepped = false;
+dbg.onDebuggerStatement = function (frame) {
+    frame.older.onStep = function () {
+        stepped = true;
+        try {
+            throw 'snow';
+        } catch (x) {
+            assertEq(x, 'snow');
+        }
+    };
+};
+
+stepped = false;
+g.eval("var caught;\n" +
+       "try {\n" +
+       "    f();\n" +
+       "} catch (x) {\n" +
+       "    caught = x;\n" +
+       "}\n");
+assertEq(stepped, true);
+assertEq(g.caught, 'mud');