Resolve #59

Author: ds5678

AssetRipper.TextureDecoder.Tests/AstcTests.cs

@@ -75,7 +75,6 @@ private static void AssertCorrectDecompression<T>(int blockWidth, int blockHeigh
 		ByteArrayDeviation.AssertMinimalDeviation(decompressedData, AndroidTextures.Logo_00.Data, maxMeanDeviation, maxStandardDeviation);
 	}
 
-	[Ignore("Bug not yet fixed")]
 	[TestCase(new byte[16] { 83, 1, 147, 104, 198, 173, 55, 116, 182, 66, 105, 11, 102, 43, 148, 125 }, 8, 8, TestName = "GetBits Should not throw in DecodeIntseq")]
 	public void DecodesBlockWithoutThrowing(byte[] block, int blockWidth, int blockHeight)
 	{

AssetRipper.TextureDecoder/Astc/AstcDecoder.cs

@@ -883,7 +883,19 @@ private static ulong BitReverseU64(ulong d, int bits)
 		[MethodImpl(MethodImplOptions.AggressiveInlining | MethodImplOptions.AggressiveOptimization)]
 		private static int GetBits(ReadOnlySpan<byte> input, int bit, int len)
 		{
-			return (BinaryPrimitives.ReadInt32LittleEndian(input[(bit / 8)..]) >> (bit % 8)) & ((1 << len) - 1);
+			ReadOnlySpan<byte> slice = input[(bit / 8)..];
+			int bitBuffer;
+			if (slice.Length >= sizeof(int))
+			{
+				bitBuffer = BinaryPrimitives.ReadInt32LittleEndian(slice);
+			}
+			else
+			{
+				Span<byte> temp = stackalloc byte[sizeof(int)];
+				slice.CopyTo(temp);
+				bitBuffer = BinaryPrimitives.ReadInt32LittleEndian(temp);
+			}
+			return (bitBuffer >> (bit % 8)) & ((1 << len) - 1);
 		}
 
 		[MethodImpl(MethodImplOptions.AggressiveInlining | MethodImplOptions.AggressiveOptimization)]