From 7119ebd59947c8514317efafc6a7ebb2e9172654 Mon Sep 17 00:00:00 2001
From: marco <marco@freepascal.org>
Date: Sat, 21 Aug 2010 04:33:51 +0000
Subject: [PATCH]  * patch from Dmitry for bug #7604, fixing the CRC problems.

git-svn-id: trunk@15864 -
---
 packages/unzip/src/unzip51g.pp | 12 +++++++++++-
 1 file changed, 11 insertions(+), 1 deletion(-)

diff --git a/packages/unzip/src/unzip51g.pp b/packages/unzip/src/unzip51g.pp
index 79d1250339..1de27749cc 100644
--- a/packages/unzip/src/unzip51g.pp
+++ b/packages/unzip/src/unzip51g.pp
@@ -2410,8 +2410,18 @@ BEGIN
     originalcrc := b AND $FFFF;
     dumpbits ( 16 );
     needbits ( 16 );
-    originalcrc := ( b AND $FFFF ) SHL 16;
+    originalcrc := originalcrc OR LongWord(( b AND $FFFF ) SHL 16);
     dumpbits ( 16 );
+
+    IF originalcrc = $08074b50 THEN BEGIN
+      { skiping possible $08074b50 data descriptor signature. see PKWARE APPNOTE.txt }
+      needbits ( 16 );
+      originalcrc := b AND $FFFF;
+      dumpbits ( 16 );
+      needbits ( 16 );
+      originalcrc := originalcrc OR LongWord(( b AND $FFFF ) SHL 16);
+      dumpbits ( 16 );
+    END;
   END;
 
   close ( infile );