diff -r 000000000000 -r 6474c204b198 toolkit/devtools/server/tests/unit/test_sourcemaps-05.js
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/toolkit/devtools/server/tests/unit/test_sourcemaps-05.js	Wed Dec 31 06:09:35 2014 +0100
@@ -0,0 +1,57 @@
+/* Any copyright is dedicated to the Public Domain.
+   http://creativecommons.org/publicdomain/zero/1.0/ */
+
+/**
+ * Check that relative source map urls work.
+ */
+
+var gDebuggee;
+var gClient;
+var gThreadClient;
+
+Components.utils.import('resource:///modules/devtools/SourceMap.jsm');
+
+// Deep in the complicated labyrinth of code that this test invokes, beneath
+// debugger callbacks, sandboxes and nested event loops, lies an exception.
+// This exception lay sleeping since the dawn of time, held captive in a
+// delicate balance of custom xpcshell error reporters and garbage data about
+// the XPCCallContext stack. But bholley dug too greedily, and too deep, and
+// awoke shadow and flame in the darkness of nsExternalHelperAppService.cpp.
+// We must now trust in deep magic to ensure that it does not awaken again.
+ignoreReportedErrors(true);
+
+function run_test()
+{
+  initTestDebuggerServer();
+  gDebuggee = addTestGlobal("test-source-map");
+  gClient = new DebuggerClient(DebuggerServer.connectPipe());
+  gClient.connect(function() {
+    attachTestTabAndResume(gClient, "test-source-map", function(aResponse, aTabClient, aThreadClient) {
+      gThreadClient = aThreadClient;
+      test_relative_source_map();
+    });
+  });
+  do_test_pending();
+}
+
+function test_relative_source_map()
+{
+  gClient.addOneTimeListener("newSource", function _onNewSource(aEvent, aPacket) {
+    do_check_eq(aEvent, "newSource");
+    do_check_eq(aPacket.type, "newSource");
+    do_check_true(!!aPacket.source);
+
+    do_check_true(aPacket.source.url.indexOf("sourcemapped.coffee") !== -1,
+                  "The new source should be a coffee file.");
+    do_check_eq(aPacket.source.url.indexOf("sourcemapped.js"), -1,
+                "The new source should not be a js file.");
+
+    finishClient(gClient);
+  });
+
+  code = readFile("sourcemapped.js")
+    + "\n//# sourceMappingURL=source-map-data/sourcemapped.map";
+
+  Components.utils.evalInSandbox(code, gDebuggee, "1.8",
+                                 getFileUrl("sourcemapped.js"), 1);
+}