Stop writing after the last file of a cabinet folder (#107)

* Stop writing after the last file of a cabinet folder

When the last data block of a folder held the end of two or more files,
WriteData still wrote the rest of the block after EndFile had closed the
last file, which threw an ObjectDisposedException. It now returns there,
as it already does when the first file in a block ends the folder.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

* Simplify the console check in the cabinet extraction test

Extract catches the ObjectDisposedException and only writes it to
Console.Error, so the test still reads the console, but without the
try/finally. It now fails with the whole exception as its message.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

---------

Co-authored-by: Claude Opus 5.5 <noreply@anthropic.com>

SabreTools.Wrappers.Test/MicrosoftCabinetTests.cs

@@ -1,3 +1,4 @@
+using System;
 using System.IO;
 using System.Linq;
 using Xunit;
@@ -56,5 +57,32 @@ namespace SabreTools.Wrappers.Test
             var actual = MicrosoftCabinet.Create(data);
             Assert.Null(actual);
         }
+
+        #region Extract
+
+        [Fact]
+        public void Extract_LastBlockEndsTwoFiles()
+        {
+            // One MS-ZIP block that holds both files
+            string path = Path.Combine(Environment.CurrentDirectory, "TestData", "MicrosoftCabinet", "mszip.cab");
+            var cabinet = MicrosoftCabinet.Create(File.ReadAllBytes(path), 0);
+            Assert.NotNull(cabinet);
+
+            // Extract catches the exception and only writes it to the console
+            string outputDirectory = Path.Combine(Path.GetTempPath(), Path.GetRandomFileName());
+            var originalError = Console.Error;
+            var error = new StringWriter();
+            Console.SetError(error);
+            cabinet.Extract(outputDirectory, includeDebug: true);
+            Console.SetError(originalError);
+
+            // Assert.True shows the whole exception, Assert.Empty cuts it off
+            Assert.True(error.ToString().Length == 0, error.ToString());
+            Assert.Equal("Hello, ", File.ReadAllText(Path.Combine(outputDirectory, "a.txt")));
+            Assert.Equal("World!", File.ReadAllText(Path.Combine(outputDirectory, "b.txt")));
+            Directory.Delete(outputDirectory, recursive: true);
+        }
+
+        #endregion
     }
 }

SabreTools.Wrappers/MicrosoftCabinet.Extraction.cs

@@ -548,7 +548,7 @@ namespace SabreTools.Wrappers
                         _fileStream.Write(data, (int)tempBytesLeft, (int)_bytesLeft);
                         tempBytesLeft += _bytesLeft;
                         if (EndFile(outputDirectory))
-                            break;
+                            return;
                     }
 
                     _fileStream.Write(data, (int)tempBytesLeft, data.Length - (int)tempBytesLeft);