diff -r 000000000000 -r 6474c204b198 browser/devtools/debugger/test/code_ugly-4.js
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/browser/devtools/debugger/test/code_ugly-4.js	Wed Dec 31 06:09:35 2014 +0100
@@ -0,0 +1,24 @@
+function a(){b()}function b(){debugger}
+//# sourceMappingURL=data:application/json;base64,eyJ2ZXJzaW9uIjozLCJmaWxlIjoiYWJjLmpzIiwic291cmNlcyI6WyJkYXRhOnRleHQvamF2YXNjcmlwdCxmdW5jdGlvbiBhKCl7YigpfSIsImRhdGE6dGV4dC9qYXZhc2NyaXB0LGZ1bmN0aW9uIGIoKXtkZWJ1Z2dlcn0iXSwibmFtZXMiOltdLCJtYXBwaW5ncyI6IkFBQUEsaUJDQUEsQ0FBQyxDQUFDLENBQUMsQ0FBQyxDQUFDLENBQUMsQ0FBQyxDQUFDLENBQUMsQ0FBQyxDQUFDLENBQUMsQ0FBQyxDQUFDLENBQUMsQ0FBQyxDQUFDLENBQUMsQ0FBQyxDQUFDLENBQUMifQ==
+
+// Generate this file by evaluating the following in a browser-environment
+// scratchpad:
+//
+//    Components.utils.import('resource://gre/modules/devtools/SourceMap.jsm');
+//
+//    let dataUrl = s => "data:text/javascript," + s;
+//
+//    let A = "function a(){b()}";
+//    let A_URL = dataUrl(A);
+//    let B = "function b(){debugger}";
+//    let B_URL = dataUrl(B);
+//
+//    let result = (new SourceNode(null, null, null, [
+//      new SourceNode(1, 0, A_URL, A),
+//      B.split("").map((ch, i) => new SourceNode(1, i, B_URL, ch))
+//    ])).toStringWithSourceMap({
+//      file: "abc.js"
+//    });
+//
+//    result.code + "\n//# " + "sourceMappingURL=data:application/json;base64," + btoa(JSON.stringify(result.map));
+