From 7743e29f8a07d122c66eac12322a5c7b85ad93d0 Mon Sep 17 00:00:00 2001
From:  <david__schmidt@users.sourceforge.net>
Date: Wed, 27 Jun 2012 04:09:16 +0000
Subject: [PATCH] Fix up SDK operations - when they're packed inside a BXY
 wrapper.

---
 .../shrinkit/MasterHeaderBlock.java           | 38 +++++++++++++++++--
 src/com/webcodepro/shrinkit/ThreadRecord.java |  2 +-
 2 files changed, 36 insertions(+), 4 deletions(-)

diff --git a/src/com/webcodepro/shrinkit/MasterHeaderBlock.java b/src/com/webcodepro/shrinkit/MasterHeaderBlock.java
index c36a1eb..4758724 100644
--- a/src/com/webcodepro/shrinkit/MasterHeaderBlock.java
+++ b/src/com/webcodepro/shrinkit/MasterHeaderBlock.java
@@ -25,12 +25,26 @@ public class MasterHeaderBlock {
 	private Date archiveModWhen;
 	private int masterVersion;
 	private long masterEof;
-	
+	private byte[] nuFileId = {0,0,0,0,0,0};
+
 	/**
 	 * Create the Master Header Block, based on the LittleEndianByteInputStream.
 	 */
 	public MasterHeaderBlock(LittleEndianByteInputStream bs) throws IOException {
-		bs.checkNuFileId();
+		int headerOffset = 0;
+		nuFileId = bs.readBytes(6);
+		
+		if (checkId(nuFileId,BXY_ID)) {
+			bs.readBytes(127 - NUFILE_ID.length);
+			headerOffset = 128;
+			int count = bs.read();
+			if (count != 0)
+				throw new IOException("This is actually a Binary II archive with multiple files in it.");
+			nuFileId = bs.readBytes(6);
+		}
+		if (!checkId(nuFileId,NUFILE_ID)) {
+			throw new IOException("Unable to decode this archive.");
+		}
 		masterCrc = bs.readWord();
 		bs.resetCrc();	// CRC is computed from this point to the end of the header
 		totalRecords = bs.readLong();
@@ -44,7 +58,7 @@ public class MasterHeaderBlock {
 			masterEof = -1;
 		}
 		// Read whatever remains of the fixed size header
-		while (bs.getTotalBytesRead() < MASTER_HEADER_LENGTH) {
+		while (bs.getTotalBytesRead() < MASTER_HEADER_LENGTH + headerOffset) {
 			bs.readByte();
 		}
 		validCrc = (masterCrc == bs.getCrcValue());
@@ -91,4 +105,22 @@ public class MasterHeaderBlock {
 	public boolean isValidCrc() {
 		return validCrc;
 	}
+	/**
+	 * Test that the requested constant is present.
+	 */
+	private boolean checkId(byte[] data, byte[] constant) {
+		for (int i = 0; i < constant.length; i++){
+			if (data[i] != constant[i])
+				return false;
+		}
+		return true;
+	}
+
+	/** Master Header Block identifier "magic" bytes. */
+	public static final byte[] NUFILE_ID = { 0x4e, (byte)0xf5, 0x46, (byte)0xe9, 0x6c, (byte)0xe5 };
+	/** Header Block identifier "magic" bytes. */
+	public static final byte[] NUFX_ID = { 0x4e, (byte)0xf5, 0x46, (byte)0xd8 };
+	/** Binay II identifier "magic" bytes. */
+	public static final byte[] BXY_ID = { 0x0a, 0x47, 0x4c };
+
 }
diff --git a/src/com/webcodepro/shrinkit/ThreadRecord.java b/src/com/webcodepro/shrinkit/ThreadRecord.java
index 4a2f198..a32003c 100644
--- a/src/com/webcodepro/shrinkit/ThreadRecord.java
+++ b/src/com/webcodepro/shrinkit/ThreadRecord.java
@@ -53,7 +53,7 @@ public class ThreadRecord {
 			if (hb.getStorageType() <= 13 ) {
 				/* supposed to be block size, but SHK v3.0.1 stored it wrong */
 				threadEof = hb.getExtraType() * 512;
-				System.out.println("Found erroneous storage type... fixing.");
+				// System.out.println("Found erroneous storage type... fixing.");
 			} else if (hb.getStorageType() == 256 &&
 					hb.getExtraType() == 280 &&
 					hb.getFileSysId() == 2 ) { // FileSysDOS33