SizeDiffPreviousPercent isn't working as expected

[byalextran]

I noticed I was using an incorrect MySQL password in my configuration.

When I updated the password, I was expecting the next update to throw an error because I had SizeDiffPreviousPercent set to 10% and the previous file size was 45 bytes (encrypted, 0 bytes raw). However, no error got thrown even though the new file size is 300+% bigger than the previous. I changed the value to 1% and ran another test that also resulted in no error.

Here you'll notice the three file sizes in question.

-rw-rw-r-- 1 alextran alextran      45 Apr 14 03:00 rsh-2019-04-14_0700.sql.bz2.enc
-rw-rw-r-- 1 alextran alextran   14735 Apr 15 03:00 rsh-2019-04-15_0700.sql.bz2.enc
-rw-rw-r-- 1 alextran alextran      45 Apr 15 23:11 rsh-2019-04-16_0311.sql.bz2.enc

The first being the backup with the wrong password. the second the right password. And the third the wrong password with SizeDiffPreviousPercent set to 1%. From my configuration, I would've assumed the last two backups would've thrown an error, but they didn't (I'm running 5.1.11).

Anyway, thought i'd mention it here.

And it's worth noting i'm a big fan of phpbu despite my two bug reports. Don't want to just be submitting bug reports without expressing any gratitude. ;) I appreciate the work you've put into phpbu. I'm glad i stumbled across it the other day and am confident it'll serve me well for the foreseeable future.

Thanks!

[sebastianfeldmann]

Uhh that sounds not good. I’ll look into this ASAP.

Thank you. I really appreciate you taking the time and reporting those bugs. And thanks you for doing it the way you do. Precise, friendly and constructive. You make it quite easy for me :)

[sebastianfeldmann]

phpbu provides something called Collectors. Those Collectors are responsible to find all backups either on your local drive or on your remote cloud storage.
Someday in the past Collectors where changed to return the current backup as well. This change was never reflected in the CheckSizeDiffPercent check.
So the check did compare the current size to the last element the collector returned. Since this is now the current backup the check always compared the current backup size to the current backup size which results in a 0% difference.

I fixed the issue by comparing the current backup to the second last, so now you should se a difference in size after all.

I also added to debug outputs for the CheckSizeDiffPercent check so if you run, phpbu --debug you get some hints what the check is actually doing.

You can get the fix by upgrading to version 5.2.2

$ phpbu --self-update

Thanks again for reporting this