getMediaIndexByTime was returning -1 at playlist boundaries

It should correctly return the first or last segment in the playlist.

@@ -1115,6 +1115,10 @@ videojs.Hls.translateMediaIndex = function(mediaIndex, original, update) {
 videojs.Hls.getMediaIndexByTime = function(playlist, time) {
   var index, counter, timeRanges, currentSegmentRange;
 
+  if (time === 0) {
+    return 0;
+  }
+
   timeRanges = [];
   for (index = 0; index < playlist.segments.length; index++) {
     currentSegmentRange = {};
@@ -1123,6 +1127,10 @@ videojs.Hls.getMediaIndexByTime = function(playlist, time) {
     timeRanges.push(currentSegmentRange);
   }
 
+  if (time >= timeRanges[timeRanges.length - 1].end) {
+    return (playlist.segments.length - 1);
+  }
+
   for (counter = 0; counter < timeRanges.length; counter++) {
     if (time >= timeRanges[counter].start && time < timeRanges[counter].end) {
       return counter;

@@ -1728,6 +1728,24 @@ test('mediaIndex is zero before the first segment loads', function() {
   strictEqual(player.hls.mediaIndex, 0, 'mediaIndex is zero');
 });
 
+test('mediaIndex returns correctly at playlist boundaries', function() {
+  player.src({
+    src: 'http://example.com/master.m3u8',
+    type: 'application/vnd.apple.mpegurl'
+  });
+
+  openMediaSource(player);
+  standardXHRResponse(requests.shift()); // master
+  standardXHRResponse(requests.shift()); // media
+
+  strictEqual(player.hls.mediaIndex, 0, 'mediaIndex is zero at first segment');
+
+  // seek to end
+  player.currentTime(40);
+
+  strictEqual(player.hls.mediaIndex, 3, 'mediaIndex is 3 at last segment');
+});
+
 test('reloads out-of-date live playlists when switching variants', function() {
   player.src({
     src: 'http://example.com/master.m3u8',