diff -r 000000000000 -r 6474c204b198 toolkit/devtools/server/tests/unit/test_trace_actor-02.js
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/toolkit/devtools/server/tests/unit/test_trace_actor-02.js	Wed Dec 31 06:09:35 2014 +0100
@@ -0,0 +1,82 @@
+/* Any copyright is dedicated to the Public Domain.
+ http://creativecommons.org/publicdomain/zero/1.0/ */
+
+/**
+ * Tests re-entrant startTrace/stopTrace calls on TraceActor.  Tests
+ * that stopTrace ends the most recently started trace when not
+ * provided with a name. Tests that starting a trace with the same
+ * name twice results in only one trace being collected for that name.
+ */
+
+var gDebuggee;
+var gClient;
+var gTraceClient;
+
+function run_test()
+{
+  initTestTracerServer();
+  gDebuggee = addTestGlobal("test-tracer-actor");
+  gClient = new DebuggerClient(DebuggerServer.connectPipe());
+  gClient.connect(function() {
+    attachTestTab(gClient, "test-tracer-actor", function(aResponse, aTabClient) {
+      gClient.attachTracer(aResponse.traceActor, function(aResponse, aTraceClient) {
+        gTraceClient = aTraceClient;
+        test_start_stop_reentrant();
+      });
+    });
+  });
+  do_test_pending();
+}
+
+function test_start_stop_reentrant()
+{
+  do_check_true(!gTraceClient.tracing, "TraceClient should start in idle state");
+
+  start_named_trace("foo")
+    .then(start_named_trace.bind(null, "foo"))
+    .then(start_named_trace.bind(null, "bar"))
+    .then(start_named_trace.bind(null, "baz"))
+    .then(stop_trace.bind(null, "bar", "bar"))
+    .then(stop_trace.bind(null, null, "baz"))
+    .then(stop_trace.bind(null, null, "foo"))
+    .then(function() {
+      do_check_true(!gTraceClient.tracing, "TraceClient should finish in idle state");
+      finishClient(gClient);
+    });
+}
+
+function start_named_trace(aName)
+{
+  let deferred = promise.defer();
+  gTraceClient.startTrace([], aName, function(aResponse) {
+    do_check_true(!!gTraceClient.tracing, "TraceClient should be in tracing state");
+    do_check_true(!aResponse.error,
+                  'startTrace should not respond with error: ' + aResponse.error);
+    do_check_eq(aResponse.type, "startedTrace",
+                'startTrace response should have "type":"startedTrace" property');
+    do_check_eq(aResponse.why, "requested",
+                'startTrace response should have "why":"requested" property');
+    do_check_eq(aResponse.name, aName,
+                'startTrace response should have the given name');
+    deferred.resolve();
+  });
+  return deferred.promise;
+}
+
+function stop_trace(aName, aExpectedName)
+{
+  let deferred = promise.defer();
+  gTraceClient.stopTrace(aName, function(aResponse) {
+    do_check_true(!aResponse.error,
+                  'stopTrace should not respond with error: ' + aResponse.error);
+    do_check_true(aResponse.type === "stoppedTrace",
+                  'stopTrace response should have "type":"stoppedTrace" property');
+    do_check_true(aResponse.why === "requested",
+                  'stopTrace response should have "why":"requested" property');
+    do_check_true(aResponse.name === aExpectedName,
+                  'stopTrace response should have name "' + aExpectedName
+                  + '", but had "' + aResponse.name + '"');
+    deferred.resolve();
+  });
+  return deferred.promise;
+}