[ scummvm-Bugs-3036679 ] RTZ: Installed V1.2 MD5

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Bugs item #3036679, was opened at 2010-07-29 20:02
Message generated for change (Tracker Item Submitted) made by optically
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Category: MD5 checksums / Detector
Group: Return to Zork
Status: Open
Resolution: None
Priority: 5
Private: No
Submitted By: Optically (optically)
Assigned to: Nobody/Anonymous (nobody)
Summary: RTZ: Installed V1.2 MD5

Initial Comment:
The 5000 bytes MD5 value for Return to Zork (V1.2, 9/29/94, installed, CD/DOS/English) -- i.e., that of the file "RTZCD.DAT" -- is currently the same as that of the V1.1 installed version, i.e., that of the V1.1 "RTZCD.DAT" file, yet undetected as such.

The issue is that both the V1.1 and the V1.2 files share the first 165125 bytes, hence a 5000 bytes md5 check cannot discriminate between those files. As a result, and because the selfsame 5000 bytes md5 is not. Something >165126 bytes, or just a fullsize one, would be necessary for the distinction. Both files are of the same size, 536064. 

I do not know whether the forum-reported md5 that entered into detector.cpp is erroneous or not, but it is at the very least incomplete. 

My md5 values are just as likewise reported on the forum by another poster, whose post is available here: http://forums.scummvm.org/viewtopic.php?p=45032#45032

// Return to Zork - English CD version 1.1 12/7/93
"rtzcd.red", "c4e2430e6b6c6ff1562a80fb4a9df24c", 276466 [56e5811fdcf83b056322664998a4401e]
// Return to Zork - English CD version 1.1 12/7/93 ( installed )
"rtzcd.dat", "a1db8c97a78dae10f91d356f16ad07b8", 536064 [f3fd89a6d6931f7fd27c6d65d1215157]
// Return to Zork - English CD version 1.2 9/29/94
"rtzcd.red", "946997d8b0aa6cb4e848bad02a1fc3d2", 276584 [31cd9197a352f58904fd8ea9ddc7924d]
// Return to Zork - English CD version 1.2 9/29/94 ( installed )
"rtzcd.dat", "a1db8c97a78dae10f91d356f16ad07b8", 536064 [f5c3c3740e9a20bbb26f7f952cf020bd] 

Note the different fullsize md5 between the two installed version.
 
The V1.2 "RTZCD.DAT" is freely available as part of the V1.2 patch in a .rar, and one can readily verify its detection as V1.1. Here: http://dlh.net/cgi-bin/dlp.cgi?lang=eng&sys=pc&file=rtzcd12.zip&ref=ps 

Tested on ScummVM 1.2.0svn51462.

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