Scary bug with truncated advanced customization

jfriend · March 6, 2011

I don't have a lot of detailed information on this because it isn't happening to me directly, just to people I'm trying to help.

But, there appears to be some sort of pretty scary bug out there that causes people's advanced customization to get truncated. I've seen it happen five times today, one on the CSS section and four times on the bottom javascript section. Each time, it's truncated somewhere in the middle and one or more junk characters are stuck on end (often a "%" character).

Needless to say, this tends to ruin a site owners customization and requires a lot of hand holding to recover from.

For the only user that I have browser info on, it happened repeatedly with the Chrome browser on a Mac. All of the users I was working with today were using the JFriend HTML5 slideshow which has a fair amount of CSS and bottom javascript so it could be the volume of data that is tripping the problem.

This sounds like a very serious bug to me because it trashes part of a user's advanced customization and I've seen it happen to multiple different people today.

Andy · March 6, 2011

Hi John, if you can recreate this would help - we'd really need more to go on - exactly what the user was doing and exactly what happened. We'd need to be able to replicate this on our test site in order to fix it, if there's something broken. Thanks.

Allen · March 6, 2011

I ran into this a couple years ago using Firefox. Somehow the mouse would
stick and select stuff in one of the boxes. I had to intentionally click outside
a box to release any selection. This happened multiple times and was posted.
I remember that I would lose most of what was in a js box. It was like I was
holding down the mouse and dragging.

jfriend · March 6, 2011

Andy wrote: »

Hi John, if you can recreate this would help - we'd really need more to go on - exactly what the user was doing and exactly what happened. We'd need to be able to replicate this on our test site in order to fix it, if there's something broken. Thanks.

I don't know how to reproduce it yet. There's definitely something busted though. Two different users working on my slideshow today showed up with truncated customization fields just today. They'd repaste in the full data and it would still be truncated after hitting update. They'd do it over and over again and finally it would take without truncating that field, then one of the other fields would be truncated.

I'll keep looking for reproducability clues, but I'll tell you right now that you're probably never going to get a perfectly reproducible test case - it's some sort of intermittent bug. I decided to post this today because, besides happening repeatedly to two customers today, I've seen this happen to other users a couple times before in the last few months.

FYI, when it happens, it's pretty horrible. User customization data is completely lost.

BradfordBenn · March 7, 2011

I am not sure if this applies so feel free to ignore it as you see fit

I was troubleshooting a similar sounding problem at the office. People would enter data into a form online but would have missing parts when submitted. it was the difference between a line break (ASCII #10) and a return character (ASCII #13). Which with their keyboard varied between using the return key and the enter key.

docwalker · March 8, 2011

I have been noticing similar problems with other sites lately. I was starting to think that it was either Google Chrome which I use for my personal browsing, or my Mac wireless keyboard. I am finding more and more situations where the text that I type and what appears on the screen are not always the same once submitted. Its really ticking me off.

I use LastPass for my logins to all of the different systems I have to access. For some strange reason My login to lastpass is rejected like 80% of the time, multiple times, before it is accepted. I know for a fact that I am typing it correctly, and I cannot figure out what is causing it.

I also see multiple examples of when typing in large blocks of text on other sites where it gets truncated. I think it has something to do with the used of the delete key in my case as I do make mistakes and frequently need to edit. I am not sure if the keyboard, or maybe Chrome is inserting the wrong character.

What is really strange is that I believe your reports about SmugMug because of the above examples. But, I have not seen the issues on SmugMug. Not sure why. I will keep an eye out for this and try some of the other browsers to see if I see similar.

BigRed · March 8, 2011

Andy wrote: »

Hi John, if you can recreate this would help - we'd really need more to go on - exactly what the user was doing and exactly what happened. We'd need to be able to replicate this on our test site in order to fix it, if there's something broken. Thanks.

I can't provide many details, but this happened to me on February 1. I had been tweaking John's HTML5 slideshow and experimenting with another customization, so was replacing my Adv Cust data repeatedly at short intervals -- but very carefully, so I'm confident it wasn't something my mouse did. All in IE7, I believe. At some point, my navigation went haywire, and I was totally baffled. John saved the day by noticing the truncation (thank you again!) and I was able to reinstate the lost code from a recent email backup. The helpdesk (ticket 226718) confirmed that there is no size limit to the customization code space. But it seemed possible that a communication glitch might have dropped characters. Since all the Adv Cust code is replaced with every update (vs. delta saves), with no apparent transmission error checking, I remember thinking it's actually surprising this doesn't happen more often. As a control, I have since added an END comment at the very bottom of each customization field that I check after updates.

jfriend · March 13, 2011

Another case of truncated customization: http://www.dgrin.com/showpost.php?p=1573923&postcount=40.

jfriend · March 14, 2011

Another customer example: http://www.dgrin.com/showpost.php?p=1574517&postcount=108

jfriend · March 24, 2011

This bug stuck another customer. More truncated bottom javascript here.

Doc, what can be done about this to make some progress here? This is a data-loss bug in advanced customization - customers can lose valuable customization data. We have no idea what triggers it, but based on the number of independent reports and the identical result everytime, it's definitely a bug of some kind. Way too much coincidence and similarity to say this is user error.

docwalker · March 24, 2011

John, Sorry for not reporting back. This is bugged. I filed it a few days ago. I have been really busy the last few days and did not get a chance to update this thread. My Fault. I added the bug to our Top list of bugs a few days ago. That will get it moving. The problem is that the sorcerers are tasked on other important tasks that need to be finished first. I will check with the PM's to make sure that it gets attention soon.

jfriend · March 24, 2011

docwalker wrote: »

John, Sorry for not reporting back. This is bugged. I filed it a few days ago. I have been really busy the last few days and did not get a chance to update this thread. My Fault. I added the bug to our Top list of bugs a few days ago. That will get it moving. The problem is that the sorcerers are tasked on other important tasks that need to be finished first. I will check with the PM's to make sure that it gets attention soon.

Thanks for the update - I just wanted to make sure that it was going to get looked at sometime relatively soon.

It's also become apparent that the whole advanced customization page just isn't very robust. In addition to this truncation issue if it, for any reason, decides that you need to log in again, it throws away all your changes which can be a total disaster. You hit save and it throws away your changes.

docwalker · March 24, 2011

Yep, I included that in the bug report. Its not good.

jfriend · October 19, 2011

This bug is still trashing user's customizations. The latest one I saw occurred here: http://www.dgrin.com/showpost.php?p=1687922&postcount=1957. We're now 9 months since initial report. It's still happening and no progress in working on it reported here.

Come on people, even if this is hard to reproduce it clearly happens and it's pretty bad when it does happen (people lose part of their customization and their site stops working).

It shouldn't be that hard to fail to commit to permanent storage a truncated customization. You can just put some checks in the submitted form that guarantee you have a fully completed form upload before committing anything to the database. You could use a client computed checksum or CRC to verify you had everything before committing to the database or you could probably just put a dummy field at the end of the form with a known code in it and make sure you had that dummy field before committing anything. I rather doubt this would be hard to protect against if you wanted to.

Scary bug with truncated advanced customization

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