diff -r 000000000000 -r 6474c204b198 browser/devtools/debugger/test/browser_dbg_sources-sorting.js
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/browser/devtools/debugger/test/browser_dbg_sources-sorting.js	Wed Dec 31 06:09:35 2014 +0100
@@ -0,0 +1,137 @@
+/* Any copyright is dedicated to the Public Domain.
+   http://creativecommons.org/publicdomain/zero/1.0/ */
+
+/**
+ * Tests that urls are correctly sorted when added to the sources widget.
+ */
+
+const TAB_URL = EXAMPLE_URL + "doc_recursion-stack.html";
+
+let gTab, gDebuggee, gPanel, gDebugger;
+let gSources, gUtils;
+
+function test() {
+  initDebugger(TAB_URL).then(([aTab, aDebuggee, aPanel]) => {
+    gTab = aTab;
+    gDebuggee = aDebuggee;
+    gPanel = aPanel;
+    gDebugger = gPanel.panelWin;
+    gSources = gDebugger.DebuggerView.Sources;
+    gUtils = gDebugger.SourceUtils;
+
+    waitForSourceShown(gPanel, ".html").then(() => {
+      addSourceAndCheckOrder(1, () => {
+        addSourceAndCheckOrder(2, () => {
+          addSourceAndCheckOrder(3, () => {
+            closeDebuggerAndFinish(gPanel);
+          });
+        });
+      });
+    });
+  });
+}
+
+function addSourceAndCheckOrder(aMethod, aCallback) {
+  gSources.empty();
+  gSources.suppressSelectionEvents = true;
+
+  let urls = [
+    { href: "ici://some.address.com/random/", leaf: "subrandom/" },
+    { href: "ni://another.address.org/random/subrandom/", leaf: "page.html" },
+    { href: "san://interesting.address.gro/random/", leaf: "script.js" },
+    { href: "si://interesting.address.moc/random/", leaf: "script.js" },
+    { href: "si://interesting.address.moc/random/", leaf: "x/script.js" },
+    { href: "si://interesting.address.moc/random/", leaf: "x/y/script.js?a=1" },
+    { href: "si://interesting.address.moc/random/x/", leaf: "y/script.js?a=1&b=2" },
+    { href: "si://interesting.address.moc/random/x/y/", leaf: "script.js?a=1&b=2&c=3" }
+  ];
+
+  urls.sort(function(a, b) {
+    return Math.random() - 0.5;
+  });
+
+  switch (aMethod) {
+    case 1:
+      for (let { href, leaf } of urls) {
+        let url = href + leaf;
+        let label = gUtils.getSourceLabel(url);
+        let dummy = document.createElement("label");
+        gSources.push([dummy, url], {
+          staged: true,
+          attachment: {
+            label: label
+          }
+        });
+      }
+      gSources.commit({ sorted: true });
+      break;
+
+    case 2:
+      for (let { href, leaf } of urls) {
+        let url = href + leaf;
+        let label = gUtils.getSourceLabel(url);
+        let dummy = document.createElement("label");
+        gSources.push([dummy, url], {
+          staged: false,
+          attachment: {
+            label: label
+          }
+        });
+      }
+      break;
+
+    case 3:
+      let i = 0
+      for (; i < urls.length / 2; i++) {
+        let { href, leaf } = urls[i];
+        let url = href + leaf;
+        let label = gUtils.getSourceLabel(url);
+        let dummy = document.createElement("label");
+        gSources.push([dummy, url], {
+          staged: true,
+          attachment: {
+            label: label
+          }
+        });
+      }
+      gSources.commit({ sorted: true });
+
+      for (; i < urls.length; i++) {
+        let { href, leaf } = urls[i];
+        let url = href + leaf;
+        let label = gUtils.getSourceLabel(url);
+        let dummy = document.createElement("label");
+        gSources.push([dummy, url], {
+          staged: false,
+          attachment: {
+            label: label
+          }
+        });
+      }
+      break;
+  }
+
+  checkSourcesOrder(aMethod);
+  aCallback();
+}
+
+function checkSourcesOrder(aMethod) {
+  let attachments = gSources.attachments;
+
+  for (let i = 0; i < attachments.length - 1; i++) {
+    let first = attachments[i].label;
+    let second = attachments[i + 1].label;
+    ok(first < second,
+      "Using method " + aMethod + ", " +
+      "the sources weren't in the correct order: " + first + " vs. " + second);
+  }
+}
+
+registerCleanupFunction(function() {
+  gTab = null;
+  gDebuggee = null;
+  gPanel = null;
+  gDebugger = null;
+  gSources = null;
+  gUtils = null;
+});