run CI on release branch

Fix: Should not throw on ARJ detection

.github/workflows/dotnetcore.yml

@@ -3,6 +3,7 @@ on:
   push:
     branches:
       - 'master'
+      - 'release'
   pull_request:
     types: [ opened, synchronize, reopened, ready_for_review ]
 

src/SharpCompress/Compressors/BZip2/CBZip2OutputStream.cs

@@ -544,6 +544,12 @@ internal sealed class CBZip2OutputStream : Stream, IStreamStack
 
     private void EndBlock()
     {
+        // Skip block processing for empty input (no data written)
+        if (last < 0)
+        {
+            return;
+        }
+
         blockCRC = mCrc.GetFinalCRC();
         combinedCRC = (combinedCRC << 1) | (int)(((uint)combinedCRC) >> 31);
         combinedCRC ^= blockCRC;

src/SharpCompress/Factories/ArjFactory.cs

@@ -28,12 +28,19 @@ namespace SharpCompress.Factories
             int bufferSize = ReaderOptions.DefaultBufferSize
         )
         {
-            var arjHeader = new ArjMainHeader(new ArchiveEncoding());
-            if (arjHeader.Read(stream) == null)
+            try
+            {
+                var arjHeader = new ArjMainHeader(new ArchiveEncoding());
+                if (arjHeader.Read(stream) == null)
+                {
+                    return false;
+                }
+                return true;
+            }
+            catch
             {
                 return false;
             }
-            return true;
         }
 
         public IReader OpenReader(Stream stream, ReaderOptions? options) =>

src/SharpCompress/SharpCompress.csproj

@@ -2,9 +2,9 @@
   <PropertyGroup>
     <AssemblyTitle>SharpCompress - Pure C# Decompression/Compression</AssemblyTitle>
     <NeutralLanguage>en-US</NeutralLanguage>
-    <VersionPrefix>0.41.0</VersionPrefix>
-    <AssemblyVersion>0.41.0</AssemblyVersion>
-    <FileVersion>0.41.0</FileVersion>
+    <VersionPrefix>0.42.1</VersionPrefix>
+    <AssemblyVersion>0.42.1</AssemblyVersion>
+    <FileVersion>0.42.1</FileVersion>
     <Authors>Adam Hathcock</Authors>
     <TargetFrameworks>net48;net481;netstandard2.0;net6.0;net8.0</TargetFrameworks>
     <AssemblyName>SharpCompress</AssemblyName>

tests/SharpCompress.Test/ArchiveTests.cs

@@ -654,4 +654,31 @@ public class ArchiveTests : ReaderTests
             Assert.Equal(3, archive.Entries.Count());
         }
     }
+
+    [Fact]
+    public void ArchiveFactory_IsArchive_NonArchiveFile_ShouldReturnFalse()
+    {
+        // Test that ArchiveFactory.IsArchive returns false instead of throwing
+        // when called on a non-archive file (regression test for issue #1064)
+        using (var stream = new MemoryStream(new byte[] { 0x00, 0x01, 0x02, 0x03, 0x04 }))
+        {
+            var result = ArchiveFactory.IsArchive(stream, out var type);
+            Assert.False(result);
+            Assert.Null(type);
+        }
+    }
+
+    [Fact]
+    public void ArchiveFactory_IsArchive_ValidArchive_ShouldReturnTrue()
+    {
+        // Test that ArchiveFactory.IsArchive correctly identifies valid archives
+        var testArchive = Path.Combine(TEST_ARCHIVES_PATH, "Zip.bzip2.noEmptyDirs.zip");
+
+        using (var stream = File.OpenRead(testArchive))
+        {
+            var result = ArchiveFactory.IsArchive(stream, out var type);
+            Assert.True(result);
+            Assert.Equal(ArchiveType.Zip, type);
+        }
+    }
 }

tests/SharpCompress.Test/Zip/ZipWriterTests.cs

@@ -1,5 +1,7 @@
+using System.IO;
 using System.Text;
 using SharpCompress.Common;
+using SharpCompress.Writers;
 using Xunit;
 
 namespace SharpCompress.Test.Zip;
@@ -9,6 +11,42 @@ public class ZipWriterTests : WriterTests
     public ZipWriterTests()
         : base(ArchiveType.Zip) { }
 
+    [Fact]
+    public void Zip_BZip2_Write_EmptyFile()
+    {
+        // Test that writing an empty file with BZip2 compression doesn't throw DivideByZeroException
+        using var memoryStream = new MemoryStream();
+        var options = new WriterOptions(CompressionType.BZip2)
+        {
+            ArchiveEncoding = new ArchiveEncoding { Default = new UTF8Encoding(false) },
+        };
+
+        using (var writer = WriterFactory.Open(memoryStream, ArchiveType.Zip, options))
+        {
+            writer.Write("test-folder/zero-byte-file.txt", Stream.Null);
+        }
+
+        Assert.True(memoryStream.Length > 0);
+    }
+
+    [Fact]
+    public void Zip_BZip2_Write_EmptyFolder()
+    {
+        // Test that writing an empty folder entry with BZip2 compression doesn't throw DivideByZeroException
+        using var memoryStream = new MemoryStream();
+        var options = new WriterOptions(CompressionType.BZip2)
+        {
+            ArchiveEncoding = new ArchiveEncoding { Default = new UTF8Encoding(false) },
+        };
+
+        using (var writer = WriterFactory.Open(memoryStream, ArchiveType.Zip, options))
+        {
+            writer.Write("test-empty-folder/", Stream.Null);
+        }
+
+        Assert.True(memoryStream.Length > 0);
+    }
+
     [Fact]
     public void Zip_Deflate_Write() =>
         Write(