Try to fix frameworks again by matching JSON.NET

src/SharpCompress/Common/Zip/StreamingZipHeaderFactory.cs

@@ -31,7 +31,7 @@ namespace SharpCompress.Common.Zip
                     FlagUtility.HasFlag(lastEntryHeader.Flags, HeaderFlags.UsePostDataDescriptor))
                 {
                     reader = (lastEntryHeader.Part as StreamingZipFilePart).FixStreamedFileLocation(ref rewindableStream);
-                    long pos = rewindableStream.Position;
+                    long? pos = rewindableStream.CanSeek ? (long?)rewindableStream.Position : null;
                     uint crc = reader.ReadUInt32();
                     if (crc == POST_DATA_DESCRIPTOR)
                     {
@@ -40,7 +40,10 @@ namespace SharpCompress.Common.Zip
                     lastEntryHeader.Crc = crc;
                     lastEntryHeader.CompressedSize = reader.ReadUInt32();
                     lastEntryHeader.UncompressedSize = reader.ReadUInt32();
-                    lastEntryHeader.DataStartPosition = pos - lastEntryHeader.CompressedSize;
+                    if (pos.HasValue)
+                    {
+                        lastEntryHeader.DataStartPosition = pos - lastEntryHeader.CompressedSize;
+                    }
                 }
                 lastEntryHeader = null;
                 uint headerBytes = reader.ReadUInt32();

src/SharpCompress/Compressor/Deflate/GZipStream.cs

@@ -355,7 +355,7 @@ namespace SharpCompress.Compressor.Deflate
             }
         }
 
-        public String FileName
+        public string FileName
         {
             get { return fileName; }
             set
@@ -372,10 +372,20 @@ namespace SharpCompress.Compressor.Deflate
                 if (fileName.EndsWith("\\"))
                     throw new InvalidOperationException("Illegal filename");
 
-                if (fileName.IndexOf("\\") != -1)
+                var index = fileName.IndexOf("\\");
+                if (index != -1)
                 {
                     // trim any leading path
-                    fileName = Path.GetFileName(fileName);
+                    int length = fileName.Length;
+                    int num = length;
+                    while (--num >= 0)
+                    {
+                        char c = fileName[num];
+                        if (c == '\\')
+                        {
+                            fileName = fileName.Substring(num + 1, length - num - 1);
+                        }
+                    }
                 }
             }
         }

src/SharpCompress/IO/RewindableStream.cs

@@ -72,10 +72,7 @@ namespace SharpCompress.IO
             get { return true; }
         }
 
-        public override bool CanSeek
-        {
-            get { return false; }
-        }
+        public override bool CanSeek => stream.CanSeek;
 
         public override bool CanWrite
         {

src/SharpCompress/project.json

@@ -1,5 +1,5 @@
 {
-    "version": "0.12.3",
+    "version": "0.12.4",
     "title": "SharpCompress - Pure C# Decompression/Compression",
     "authors": [ "Adam Hathcock" ],
     "language": "en-US",
@@ -11,29 +11,19 @@
         "description": "SharpCompress is a compression library for .NET/Mono/Silverlight/WP7/WindowsStore that can unrar, decompress 7zip, zip/unzip, tar/untar bzip2/unbzip2 and gzip/ungzip with forward-only reading and file random access APIs. Write support for zip/tar/bzip2/gzip is implemented.",
         "requireLicenseAcceptance": false
     },
+    "buildOptions": {
+        "warningsAsErrors": true,
+        "allowUnsafe": true
+    },
     "frameworks": {
         "net35": {
-            "buildOptions": {
-                "warningsAsErrors": true,
-                "allowUnsafe": true
-            }
         },
         "net40": {
-            "buildOptions": {
-                "warningsAsErrors": true,
-                "allowUnsafe": true
-            }
         },
         "net45": {
-            "buildOptions": {
-                "warningsAsErrors": true,
-                "allowUnsafe": true
-            }
         },
-        "sl5": {
+        ".NETPortable,Version=v4.0,Profile=Profile328": {
             "buildOptions": {
-                "warningsAsErrors": true,
-                "allowUnsafe": true,
                 "define": [ "NO_FILE", "NO_CRYPTO", "SILVERLIGHT" ]
             },
             "frameworkAssemblies": {
@@ -44,8 +34,6 @@
         },
         ".NETPortable,Version=v4.5,Profile=Profile259": {
             "buildOptions": {
-                "warningsAsErrors": true,
-                "allowUnsafe": true,
                 "define": [ "NO_FILE", "NO_CRYPTO", "SILVERLIGHT" ]
             },
             "frameworkAssemblies": {
@@ -64,8 +52,6 @@
         },
         "netstandard1.0": {
             "buildOptions": {
-                "warningsAsErrors": true,
-                "allowUnsafe": true,
                 "define": [ "NO_FILE", "NO_CRYPTO" ]
             },
             "dependencies": {
@@ -79,10 +65,6 @@
             }
         },
         "netstandard1.3": {
-            "buildOptions": {
-                "warningsAsErrors": true,
-                "allowUnsafe": true
-            },
             "dependencies": {
                 "System.Collections": "4.0.11",
                 "System.Diagnostics.Debug": "4.0.11",

test/SharpCompress.Test/ForwardOnlyStream.cs

@@ -0,0 +1,64 @@
+using System;
+using System.IO;
+
+namespace SharpCompress.Test
+{
+    public class ForwardOnlyStream : Stream
+    {
+        private readonly Stream stream;
+
+        public bool IsDisposed { get; private set; }
+
+        public ForwardOnlyStream(Stream stream)
+        {
+            this.stream = stream;
+        }
+
+        protected override void Dispose(bool disposing)
+        {
+            base.Dispose(disposing);
+            stream.Dispose();
+            IsDisposed = true;
+        }
+
+        public override bool CanRead => true;
+
+        public override bool CanSeek => false;
+        public override bool CanWrite => false;
+
+        public override void Flush()
+        {
+            throw new NotSupportedException();
+        }
+
+        public override long Length
+        {
+            get { throw new NotSupportedException(); }
+        }
+
+        public override long Position
+        {
+            get { throw new NotSupportedException(); }
+            set { throw new NotSupportedException(); }
+        }
+
+        public override int Read(byte[] buffer, int offset, int count)
+        {
+            return stream.Read(buffer, offset, count);
+        }
+
+        public override long Seek(long offset, SeekOrigin origin)
+        {
+            throw new NotSupportedException();
+        }
+
+        public override void SetLength(long value)
+        {
+            throw new NotSupportedException();
+        }
+
+        public override void Write(byte[] buffer, int offset, int count)
+        {throw new NotSupportedException();
+        }
+    }
+}

test/SharpCompress.Test/ReaderTests.cs

@@ -18,7 +18,7 @@ namespace SharpCompress.Test
         {
             foreach (var path in testArchives)
             {
-                using (Stream stream = File.OpenRead(path))
+                using (Stream stream = new ForwardOnlyStream(File.OpenRead(path)))
                 using (IReader reader = ReaderFactory.Open(stream))
                 {
                     UseReader(this, reader, expectedCompression);