Add failing test coverage of incorrect default preview time

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

@@ -33,7 +33,7 @@ public class LegacyBeatmapDecoderTest
         [Test]
         public void TestDecodeBeatmapVersion()
         {
-            using (var resStream = TestResources.OpenResource("beatmap-version.osu"))
+            using (var resStream = TestResources.OpenResource("beatmap-version-6.osu"))
             using (var stream = new LineBufferedReader(resStream))
             {
                 var decoder = Decoder.GetDecoder<Beatmap>(stream);
@@ -45,6 +45,25 @@ public void TestDecodeBeatmapVersion()
             }
         }
 
+        [TestCase(false)]
+        [TestCase(true)]
+        public void TestPreviewPointWithOffsets(bool applyOffsets)
+        {
+            using (var resStream = TestResources.OpenResource("beatmap-version-4.osu"))
+            using (var stream = new LineBufferedReader(resStream))
+            {
+                var decoder = Decoder.GetDecoder<Beatmap>(stream);
+                ((LegacyBeatmapDecoder)decoder).ApplyOffsets = applyOffsets;
+                var working = new TestWorkingBeatmap(decoder.Decode(stream));
+
+                Assert.AreEqual(4, working.BeatmapInfo.BeatmapVersion);
+                Assert.AreEqual(4, working.Beatmap.BeatmapInfo.BeatmapVersion);
+                Assert.AreEqual(4, working.GetPlayableBeatmap(new OsuRuleset().RulesetInfo, Array.Empty<Mod>()).BeatmapInfo.BeatmapVersion);
+
+                Assert.AreEqual(-1, working.BeatmapInfo.Metadata.PreviewTime);
+            }
+        }
+
         [Test]
         public void TestDecodeBeatmapGeneral()
         {
@@ -915,10 +934,11 @@ public void TestSliderLengthExtensionEdgeCase()
             }
         }
 
-        [Test]
-        public void TestLegacyDefaultsPreserved()
+        [TestCase(false)]
+        [TestCase(true)]
+        public void TestLegacyDefaultsPreserved(bool applyOffsets)
         {
-            var decoder = new LegacyBeatmapDecoder { ApplyOffsets = false };
+            var decoder = new LegacyBeatmapDecoder { ApplyOffsets = applyOffsets };
 
             using (var memoryStream = new MemoryStream())
             using (var stream = new LineBufferedReader(memoryStream))

osu.Game.Tests/Resources/beatmap-version-4.osu

@@ -0,0 +1,4 @@
+osu file format v4
+
+[General]
+PreviewTime: -1