From 452cbeefa25fc7ecaad58f2eb7bbaa0b7ea3aacf Mon Sep 17 00:00:00 2001
From: Andreas Kupries <andreas_kupries@users.sourceforge.net>
Date: Wed, 4 Aug 2004 21:49:08 +0000
Subject: [PATCH] 	* library/zipvfs.tcl: Fixed [SF Tclvfs Bug 1003574].
 Added code 	  preventing us from seeking before the beginning of the zip
 file.

---
 ChangeLog          | 5 +++++
 library/zipvfs.tcl | 7 ++++++-
 2 files changed, 11 insertions(+), 1 deletion(-)

diff --git a/ChangeLog b/ChangeLog
index eda8f77..2d88782 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,8 @@
+2004-08-04  Andreas Kupries  <andreask@activestate.com>
+
+	* library/zipvfs.tcl: Fixed [SF Tclvfs Bug 1003574]. Added code
+	  preventing us from seeking before the beginning of the zip file.
+
 2004-07-15  Andreas Kupries  <andreask@activestate.com>
 
 	* doc/vfs-fsapi.man: Clarified description of the close callback
diff --git a/library/zipvfs.tcl b/library/zipvfs.tcl
index 80e48d9..87f656d 100644
--- a/library/zipvfs.tcl
+++ b/library/zipvfs.tcl
@@ -328,7 +328,12 @@ proc zip::Data {fd arr {varPtr ""} {verify 0}} {
 proc zip::EndOfArchive {fd arr} {
     upvar 1 $arr cb
 
-    seek $fd -512 end
+    # [SF Tclvfs Bug 1003574]. Do not seek over beginning of file.
+    seek $fd 0 end
+    set n [tell $fd]
+    if {$n < 512} {set n -$n} else {set n -512}
+    seek $fd $n end
+
     set hdr [read $fd 512]
     set pos [string first "PK\05\06" $hdr]
     if {$pos == -1} {
-- 
2.23.0