Add unit test

osu.Game.Tests/Beatmaps/Formats/LegacyBeatmapDecoderTest.cs

@@ -194,6 +194,34 @@ namespace osu.Game.Tests.Beatmaps.Formats
             }
         }
 
+        [Test]
+        public void TestDecodeOverlappingTimingPoints()
+        {
+            var decoder = new LegacyBeatmapDecoder { ApplyOffsets = false };
+
+            using (var resStream = TestResources.OpenResource("overlapping-control-points.osu"))
+            using (var stream = new StreamReader(resStream))
+            {
+                var controlPoints = decoder.Decode(stream).ControlPointInfo;
+
+                Assert.That(controlPoints.DifficultyPoints, Has.Count.EqualTo(2));
+                Assert.That(controlPoints.DifficultyPoints[0].SpeedMultiplier, Is.EqualTo(1.5).Within(0.1));
+                Assert.That(controlPoints.DifficultyPoints[1].SpeedMultiplier, Is.EqualTo(0.75).Within(0.1));
+
+                Assert.That(controlPoints.EffectPoints, Has.Count.EqualTo(2));
+                Assert.That(controlPoints.EffectPoints[0].KiaiMode, Is.True);
+                Assert.That(controlPoints.EffectPoints[1].KiaiMode, Is.True);
+
+                Assert.That(controlPoints.SamplePoints, Has.Count.EqualTo(2));
+                Assert.That(controlPoints.SamplePoints[0].SampleBank, Is.EqualTo("drum"));
+                Assert.That(controlPoints.SamplePoints[1].SampleBank, Is.EqualTo("normal"));
+
+                Assert.That(controlPoints.TimingPoints, Has.Count.EqualTo(2));
+                Assert.That(controlPoints.TimingPoints[0].BeatLength, Is.EqualTo(500));
+                Assert.That(controlPoints.TimingPoints[1].BeatLength, Is.EqualTo(250));
+            }
+        }
+
         [Test]
         public void TestDecodeBeatmapColours()
         {

osu.Game.Tests/Resources/overlapping-control-points.osu

@@ -0,0 +1,11 @@
+osu file format v14
+
+[TimingPoints]
+
+// Timing -> Inherited
+0,500,4,2,0,100,1,0
+0,-66.6666666666667,4,3,0,100,0,1
+
+// Inherited -> Timing
+1000,-133.333333333333,4,1,0,100,0,1
+1000,250,4,2,0,100,1,0