Make the sort used for filetered link hints stable.

JavaScript's sort function is not stable; this PR makes the sort used for filtered link hints stable.

There are two reasons for doing this:

- High-scoring hints are more likely to keep the same hint string as the user continues typing. (Currently, the hints assigned change based on the vaguaries of the non-stable sort.)

- For equal-scoring hints, we retain the visit-child-before-parent ordering (which is used to NOT match a parent's text if we have already matched that text in a child).

And, as a result of all of that, the UX is more predictable and hence better.

1 files changed, 7 insertions, 4 deletions

diff --git a/tests/dom_tests/dom_tests.coffee b/tests/dom_tests/dom_tests.coffee
index a79735ae..9d703774 100644
--- a/tests/dom_tests/dom_tests.coffee
+++ b/tests/dom_tests/dom_tests.coffee
@@ -185,18 +185,21 @@ context "Filtered link hints",
 
     should "label the hints", ->
       hintMarkers = getHintMarkers()
-      for i in [0...4]
-        assert.equal (i + 1).toString(), hintMarkers[i].textContent.toLowerCase()
+      expectedMarkers = [1..4].map (m) -> m.toString()
+      actualMarkers = [0...4].map (i) -> hintMarkers[i].textContent.toLowerCase()
+      assert.equal expectedMarkers.length, actualMarkers.length
+      for marker in expectedMarkers
+        assert.isTrue marker in actualMarkers
 
     should "narrow the hints", ->
       hintMarkers = getHintMarkers()
       sendKeyboardEvent "T"
       sendKeyboardEvent "R"
       assert.equal "none", hintMarkers[0].style.display
-      assert.equal "1", hintMarkers[1].hintString
+      assert.equal "3", hintMarkers[1].hintString
       assert.equal "", hintMarkers[1].style.display
       sendKeyboardEvent "A"
-      assert.equal "2", hintMarkers[3].hintString
+      assert.equal "1", hintMarkers[3].hintString
 
   context "Image hints",