error detection

UnRarDotNet/RarStream.cs

@@ -49,10 +49,8 @@ namespace UnRarDotNet
 					while (_size == null && !_close)
 						Monitor.Wait(this);
 				}
-				if (_ex != null)
-					throw _ex;
-				if (_size == null)
-					throw new NotSupportedException();
+				if (_close)
+					throw new IOException("Decompression failed", _ex);
 				return _size.Value;
 			}
 		}
@@ -140,14 +138,6 @@ namespace UnRarDotNet
 		}
 		public override long Seek(long offset, SeekOrigin origin)
 		{
-			Go();
-			lock (this)
-			{
-				while (_size == null && !_close)
-					Monitor.Wait(this);
-				if (_size == null)
-					throw new NotSupportedException();
-			}
 			switch (origin)
 			{
 				case SeekOrigin.Begin:
@@ -157,9 +147,14 @@ namespace UnRarDotNet
 					_seek_to = Position + offset;
 					break;
 				case SeekOrigin.End:
-					_seek_to = _size.Value + offset;
+					_seek_to = Length + offset;
 					break;
 			}
+			if (_seek_to.Value > Length)
+			{
+				_seek_to = null;
+				throw new IOException("Invalid seek");
+			}
 			if (_seek_to.Value == _pos)
 			{
 				_seek_to = null;
@@ -174,8 +169,6 @@ namespace UnRarDotNet
 					_buffer = null;
 					Monitor.Pulse(this);
 				}
-				//_seek_to = null;
-				//throw new NotSupportedException("cannot seek backwards");
 			}
 			return _seek_to.Value;
 		}
@@ -242,6 +235,7 @@ namespace UnRarDotNet
 			{
 				do
 				{
+					bool foundFile = false;
 					_unrar.Open(_path, Unrar.OpenMode.Extract);
 					while (_unrar.ReadHeader())
 					{
@@ -256,6 +250,7 @@ namespace UnRarDotNet
 								}
 							}
 							_unrar.Test();
+							foundFile = true;
 							break;
 						}
 						else
@@ -263,6 +258,13 @@ namespace UnRarDotNet
 					}
 					_unrar.Close();
 					lock (this)
+					{
+						if (!foundFile)
+						{
+							_ex = new FileNotFoundException();
+							break;
+						}
+						else
 						{
 							_eof = true;
 							Monitor.Pulse(this);
@@ -273,6 +275,7 @@ namespace UnRarDotNet
 							_rewind = false;
 							_eof = false;
 						}
+					}
 				} while (true);
 			}
 			catch (Exception ex)