now throws an exception if not handled using delegates.

Author: jfreilly

src/Core/FileSystemScanner.cs

@@ -286,6 +286,58 @@ public bool ContinueRunning
 	public delegate void FileFailureHandler(object sender, ScanFailureEventArgs e);
 	#endregion
 
+    /// <summary>
+    /// An exception encountered dutring scanning.
+    /// </summary>
+#if !NETCF_1_0 && !NETCF_2_0
+    [Serializable]
+#endif
+    public class ScanException : SharpZipBaseException
+    {
+        /// <summary>
+        /// Initializes a new instance of the <see cref="ScanException"/> class.
+        /// </summary>
+        public ScanException()
+        {
+        }
+
+        /// <summary>
+        /// Initializes a new instance of the <see cref="ScanException"/> class.
+        /// </summary>
+        /// <param name="message">The message.</param>
+        public ScanException(string message)
+            : base(message)
+        {
+        }
+
+        /// <summary>
+        /// Initializes a new instance of the <see cref="ScanException"/> class.
+        /// </summary>
+        /// <param name="message">The message.</param>
+        /// <param name="innerException">The inner exception.</param>
+        public ScanException(string message, Exception innerException)
+            : base(message, innerException)
+        {
+        }
+
+#if !NETCF_1_0 && !NETCF_2_0
+        /// <summary>
+        /// Initializes a new instance of the <see cref="ScanException"/> class.
+        /// </summary>
+        /// <param name="info">The <see cref="T:System.Runtime.Serialization.SerializationInfo"/> that holds the serialized object data about the exception being thrown.</param>
+        /// <param name="context">The <see cref="T:System.Runtime.Serialization.StreamingContext"/> that contains contextual information about the source or destination.</param>
+        /// <exception cref="T:System.ArgumentNullException">The <paramref name="info"/> parameter is null. </exception>
+        /// <exception cref="T:System.Runtime.Serialization.SerializationException">The class name is null or <see cref="P:System.Exception.HResult"/> is zero (0). </exception>
+        public ScanException(
+            System.Runtime.Serialization.SerializationInfo info,
+            System.Runtime.Serialization.StreamingContext context
+            )
+            : base(info, context)
+        {
+        }
+#endif
+    }
+
 	/// <summary>
 	/// FileSystemScanner provides facilities scanning of files and directories.
 	/// </summary>
@@ -367,11 +419,14 @@ public FileSystemScanner(IScanFilter fileFilter, IScanFilter directoryFilter)
 		/// <param name="e">The exception detected.</param>
 		void OnDirectoryFailure(string directory, Exception e)
 		{
-			if ( DirectoryFailure == null ) {
-				alive_ = false;
-			} else {
+            DirectoryFailureHandler handler = DirectoryFailure;
+            if (handler == null) {
+                alive_ = false;
+                throw new ScanException("Directory scan failure", e);
+            }
+            else {
 				ScanFailureEventArgs args = new ScanFailureEventArgs(directory, e);
-				DirectoryFailure(this, args);
+				handler(this, args);
 				alive_ = args.ContinueRunning;
 			}
 		}
@@ -383,8 +438,10 @@ void OnDirectoryFailure(string directory, Exception e)
 		/// <param name="e">The exception detected.</param>
 		void OnFileFailure(string file, Exception e)
 		{
-			if ( FileFailure == null ) {
-				alive_ = false;
+            FileFailureHandler handler = FileFailure;
+			if ( handler == null ) {
+                alive_ = false;
+                throw new ScanException("File failure", e);
 			} else {
 				ScanFailureEventArgs args = new ScanFailureEventArgs(file, e);
 				FileFailure(this, args);
@@ -483,7 +540,7 @@ void ScanDir(string directory, bool recurse)
 				}
 			}
 			catch (Exception e) {
-				OnDirectoryFailure(directory, e);
+                OnDirectoryFailure(directory, e);
 			}
 
 			if ( alive_ && recurse ) {
@@ -499,7 +556,7 @@ void ScanDir(string directory, bool recurse)
 					}
 				}
 				catch (Exception e) {
-					OnDirectoryFailure(directory, e);
+                    OnDirectoryFailure(directory, e);
 				}
 			}
 		}