MSI installer flaw
EA Durbin
ead1234 at hotmail.com
Thu May 25 20:45:58 CDT 2006
Currently the MSI Installer is working backwards, In the file files.c it
reads the files from the msi package and iterates through them and queries
the Media table in order by LastSequence. The sort order for the media table
should be DiskId according to MSDN. Just changing the sort order wont work
unless the msi installer is revamped to work the right way. The code is
written wrong for this. Currently its using LIST_FOR_EACH_ENTRY in the
Install Files function for the files and then trying to ready the media per
file using the sequence number of the file in the query on the media table
using the file sequence as last sequence and returning the results order by
LastSequence.
It should first be reading the Media table first and sorting by DiskId. The
installer then iterates through each row returned by the query from the
media table and then for each file in the file table that falls within that
disk id it should ready the media. Currently wine is doing it backwards
which ends up trying to ready the wrong media if the last sequence.
It needs to read the media table, then starting with DiskId 1, iterate
through all of disk Id 1 and read from the file table order by sequence
until it reaches the last sequence as indicated in the media table for the
working DiskId, then it jumps to the next DiskId 2, 3, and so on. The
lastsequence of the working DiskId should always be greater than that of the
last sequence of the previous DiskId, if not the results should be skipped,
currently it is trying to read from DiskId's that have zero as the
LastSequence but 22 as the DiskId. Zero indicates the first entry in the
media table(if your in DiskId 1). as you increment through the DiskId's the
LastSequence should increment as well, if it doesnt you skip that install
media.
This is what causes the cabinet bugs in bugs #4533 and #5139.
A quick fix , but not the solution would be to change the query so it
doesn't return the results from the media table if the LastSequence is 0 and
the DiskId is greater than 1.
The solution would be to rewrite the installer to do things the right way
querying the Media table first, and then installing the files in order from
the media table.
If someone could help me work on this it would be much appreciated as I'm
kind of rusty in C, I'm a perl monger by trade and not very familiar with
wine's msi innerworkings.
http://msdn.microsoft.com/library/default.asp?url=/library/en-us/msi/setup/media_table.
http://msdn.microsoft.com/library/en-us/msi/setup/ordering_file_sequence_numbers_in_a_cabinet_file_table_and_media_table.asp
http://msdn.microsoft.com/library/en-us/msi/setup/file_table.asp?frame=true
As you'll see in MSDN the file and media table sequence and LastSequence
correspond with one another. Each has checks upon the other to determine the
proper install order.
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