diff -r 000000000000 -r 6474c204b198 js/src/jit-test/tests/debug/Script-clearBreakpoint-02.js
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/js/src/jit-test/tests/debug/Script-clearBreakpoint-02.js	Wed Dec 31 06:09:35 2014 +0100
@@ -0,0 +1,26 @@
+// A breakpoint cleared during dispatch does not fire.
+// (Breakpoint dispatch is well-behaved even when breakpoint handlers clear other breakpoints.)
+
+var g = newGlobal();
+var dbg = Debugger(g);
+var log = '';
+dbg.onDebuggerStatement = function (frame) {
+    var s = frame.script;
+    function handler(i) {
+        if (i === 1)
+            return function () { log += i; s.clearBreakpoint(h[1]); s.clearBreakpoint(h[2]); };
+        return function () { log += i; };
+    }
+    var offs = s.getLineOffsets(g.line0 + 2);
+    var h = [];
+    for (var i = 0; i < 4; i++) {
+        h[i] = {hit: handler(i)};
+        for (var j = 0; j < offs.length; j++)
+            s.setBreakpoint(offs[j], h[i]);
+    }
+};
+
+g.eval("var line0 = Error().lineNumber;\n" +
+       "debugger;\n" +          // line0 + 1
+       "result = 'ok';\n");     // line0 + 2
+assertEq(log, '013');