From 69cd6ee1997975e575b1a50f6b054c9e6d69c608 Mon Sep 17 00:00:00 2001
From: barubary <barubary@64c19138-535a-11de-9335-abd5230c83eb>
Date: Thu, 21 Apr 2011 14:16:59 +0000
Subject: [PATCH] C#: added built-in check for arm9.bin in LZ-Overlay
 decompression, as it has some extra bytes that should be ignored when
 decompressing. Only the file-based methods can handle that of course. Perhaps
 the extra bytes should also be copied to the output file however, which is
 currently not the case.

---
 CSharp/DSDecmp/Formats/CompressionFormat.cs |  4 +--
 CSharp/DSDecmp/Formats/LZOvl.cs             | 36 ++++++++++++++++++++-
 2 files changed, 37 insertions(+), 3 deletions(-)

diff --git a/CSharp/DSDecmp/Formats/CompressionFormat.cs b/CSharp/DSDecmp/Formats/CompressionFormat.cs
index 97d48c4..e54e412 100644
--- a/CSharp/DSDecmp/Formats/CompressionFormat.cs
+++ b/CSharp/DSDecmp/Formats/CompressionFormat.cs
@@ -19,7 +19,7 @@ namespace DSDecmp.Formats
         /// <param name="file">The name of the file to check.</param>
         /// <returns>False if the file can certainly not be decompressed using this decompressor.
         /// True if the file may potentially be decompressed using this decompressor.</returns>
-        public bool Supports(string file)
+        public virtual bool Supports(string file)
         {
             // open the file, and delegate to the decompressor-specific code.
             using (FileStream fstr = new FileStream(file, FileMode.Open))
@@ -49,7 +49,7 @@ namespace DSDecmp.Formats
         /// </summary>
         /// <param name="infile">The file to decompress.</param>
         /// <param name="outfile">The target location of the decompressed file.</param>
-        public void Decompress(string infile, string outfile)
+        public virtual void Decompress(string infile, string outfile)
         {
             // make sure the output directory exists
             string outDirectory = Path.GetDirectoryName(outfile);
diff --git a/CSharp/DSDecmp/Formats/LZOvl.cs b/CSharp/DSDecmp/Formats/LZOvl.cs
index 65e4dcc..dd6bde1 100644
--- a/CSharp/DSDecmp/Formats/LZOvl.cs
+++ b/CSharp/DSDecmp/Formats/LZOvl.cs
@@ -9,10 +9,24 @@ namespace DSDecmp.Formats
     /// The LZ-Overlay compression format. Compresses part of the file from end to start.
     /// Is used for the 'overlay' files in NDS games, as well as arm9.bin.
     /// Note that the last 12 bytes should not be included in the 'inLength' argument when
-    /// decompressing arm9.bin.
+    /// decompressing arm9.bin. This is done automatically if a file is given instead of a stream.
     /// </summary>
     public class LZOvl : CompressionFormat
     {
+        #region Method: Supports(string file)
+        public override bool Supports(string file)
+        {
+            using (FileStream fstr = File.OpenRead(file))
+            {
+                long fLength = fstr.Length;
+                // arm9.bin is special in the sense that the last 12 bytes should/can be ignored.
+                if (Path.GetFileName(file) == "arm9.bin")
+                    fLength -= 0xC;
+                return this.Supports(fstr, fLength);
+            }
+        }
+        #endregion
+
         #region Method: Supports(Stream, long)
         public override bool Supports(System.IO.Stream stream, long inLength)
         {
@@ -56,6 +70,26 @@ namespace DSDecmp.Formats
         }
         #endregion
 
+        #region Method: Decompress(string, string)
+        public override void Decompress(string infile, string outfile)
+        {
+            // make sure the output directory exists
+            string outDirectory = Path.GetDirectoryName(outfile);
+            if (!Directory.Exists(outDirectory))
+                Directory.CreateDirectory(outDirectory);
+            // open the two given files, and delegate to the format-specific code.
+            using (FileStream inStream = new FileStream(infile, FileMode.Open),
+                             outStream = new FileStream(outfile, FileMode.Create))
+            {
+                long fLength = inStream.Length;
+                // arm9.bin needs special attention
+                if (Path.GetFileName(infile) == "arm9.bin")
+                    fLength -= 0xC;
+                this.Decompress(inStream, fLength, outStream);
+            }
+        }
+        #endregion
+
         public override void Decompress(System.IO.Stream instream, long inLength, System.IO.Stream outstream)
         {
             #region Format description