Is Excel A Polluter? - 03/01/11 03:54 PM
It appears that Microsoft Excel is capable of modifying Time Machine historical files.
In another thread I couldn't understand why, after a password was lost, I could not replace a password-protected file with a pre-password version from either Time Machine or Super Duper. These were the critical backstops I should have been able to rely on.
After getting the password and removing it from the Excel file, I did an immediate Time Machine backup. That meant I now had a clean (password free) version on both my main drive and on my Time Machine drive.
I then ran a couple of TM experiments.
1. I replaced the non-password version with a password version (made after the password was introduced) and, as expected, the password was needed.
2. I replaced the password version with the new TM non-password version. The file opened without the password.
3. I then replaced the non-password version with older TM copies, from as long ago as a month before the password was introduced, and every single one wanted a password. I was expecting to get the files originally saved by TM, which were non-password copies.
This seems to suggest a couple of problems:
1. Microsoft Excel is "taking liberties" and inserting a password where it should not - on the historical files of both Time Machine and Super Duper.
2. Time Machine is allowing historical data to be modified when it should not. I'm assuming the same type of file modification happened to the Super Duper drive backup made the day prior to password introduction.
3. Excel does not fix its mistakes. Although the password requirement went backwards through old TM files, a change to non-password did not.
Is there a hole in my logic?
ryck
In another thread I couldn't understand why, after a password was lost, I could not replace a password-protected file with a pre-password version from either Time Machine or Super Duper. These were the critical backstops I should have been able to rely on.
After getting the password and removing it from the Excel file, I did an immediate Time Machine backup. That meant I now had a clean (password free) version on both my main drive and on my Time Machine drive.
I then ran a couple of TM experiments.
1. I replaced the non-password version with a password version (made after the password was introduced) and, as expected, the password was needed.
2. I replaced the password version with the new TM non-password version. The file opened without the password.
3. I then replaced the non-password version with older TM copies, from as long ago as a month before the password was introduced, and every single one wanted a password. I was expecting to get the files originally saved by TM, which were non-password copies.
This seems to suggest a couple of problems:
1. Microsoft Excel is "taking liberties" and inserting a password where it should not - on the historical files of both Time Machine and Super Duper.
2. Time Machine is allowing historical data to be modified when it should not. I'm assuming the same type of file modification happened to the Super Duper drive backup made the day prior to password introduction.
3. Excel does not fix its mistakes. Although the password requirement went backwards through old TM files, a change to non-password did not.
Is there a hole in my logic?
ryck