Apple

I can’t find any good list for questions about hdiutil, so this is going to xcode-users because my use is related to project building.

I use hdiutil to create a disk image of my installer package. Because I want to set the icon of the image, I create it writable (UDRW) so I can call SetFile –a C on it.

After this, I use hdiutil to convert it to a compressed read only image.

Before the conversion to read only compressed, everything in the image is fine. After the conversion, I wind up in the odd situation that my Welcome.txt file has been wiped out and replaced with 16 bytes of zeros. No other file is touched.

I have now reproduced this problem with an image containing nothing but the Welcome.txt file, on both a PPC and Intel machine. The source image (UDRW) is fine, the dest image (UDZO, zlib-level=9) is corrupted.

Has anyone seen anything like this? It’s completely baffling. If I can’t trust my disk image making tool, how can I put my code out with any confidence?

David Litwin

BigFix, Inc.

P.S. If anyone is curious, here is a script (included in my radar report #4662414) that demonstrates the bug on my PPC and Intel machine. I’m curious if anyone else sees it:

#!/bin/sh

echo "Create the source ImageDir"

mkdir ImageDir

echo "This welcome text will get wiped out" > ImageDir/Welcome.txt

echo

echo "Create the writable image"

echo hdiutil create -srcfolder "ImageDir" -volname "hdiutil-bug" -format UDRW -layout NONE -fs 'HFS+' -ov "Writable.dmg"

hdiutil create -srcfolder "ImageDir" -volname "hdiutil-bug" -format UDRW -layout NONE -fs 'HFS+' -ov "Writable.dmg"

echo

echo "Create the compressed read only image from the writable image"

echo hdiutil convert "Writable.dmg" -format UDZO -o "Compressed.dmg" -ov -imagekey zlib-level=9

hdiutil convert "Writable.dmg" -format UDZO -o "Compressed.dmg" -ov -imagekey zlib-level=9

echo

echo "Mount and check the contents of the Writable image"

mountLine=`hdiutil attach "Writable.dmg" | tail -n 1`

disk=`expr "$mountLine" : '$[^ ]*$.*$'`

volLoc=`expr "$mountLine" : '[^ ]*[^\/]*$.*$$'`

hexdump -C "$volLoc/Welcome.txt"

hdiutil detach -force "$disk"

echo

echo "Mount and check the contents of the compressed read only image"

mountLine=`hdiutil attach "Compressed.dmg" | tail -n 1`

disk=`expr "$mountLine" : '$[^ ]*$.*$'`

volLoc=`expr "$mountLine" : '[^ ]*[^\/]*$.*$$'`

hexdump -C "$volLoc/Welcome.txt"

hdiutil detach -force "$disk"

echo