Merge pull request #1067 from adamhathcock/adam/fix-arj-factory

Fix: Should not throw on ARJ detection

Author: adamhathcock

src/SharpCompress/Factories/ArjFactory.cs

@@ -28,12 +28,19 @@ public override bool IsArchive(
             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>0.42.0</VersionPrefix>
-    <AssemblyVersion>0.42.0</AssemblyVersion>
-    <FileVersion>0.42.0</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 void ArchiveFactory_Open_WithRawFileStream()
             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);
+        }
+    }
 }