robert_inventor
7th October 2012 09:25 UTC
Incomplete download 7K smaller - Any thoughts?
Hi there, I know this is probably nothing to do with NSIS, but it is a curious thing that is happening to just one of my users downloading my NSIS installer, and I have no idea what the reason might be and wondered if any of you know. After all presumably many of you here distribute your installers and so have probably encountered most of the issues that can occur.
Every time he downloads it then it is just a bit smaller than it should be. He has no issues runing installers of other programs. I tried sending it as an attachment and the same issue occurs.
I asked him to find the exact size in bytes and he says it is 10,313,728 bytes. It should be 10,319,560 bytes so the copy he downloads is about 7 KB too small.
I am just going to try sending him a zip instead and to tell him how to install the program manually, so will see if that works.
I wondered if it could be a virus, but if so why only my program affected and nothing else - and why would it be smaller as a result - usually viruses make a program larger - and you do get stealth viruses, cavity viruses, but the whole point in those viruses is that they don't change the file size at all. So a virus seems unlikely - and he is protected from viruses via Trend Micro.
Any thoughts anyone?
Robert (Walker)
MSG
7th October 2012 09:38 UTC
Assuming you don't append extra content to the compiled installer exe manually, the installer should give a CRC error ('NSIS Error') upon execution if there is some data missing. I am therefore assuming that this user cannot run your executable. If he/she can, I'm betting the filesize isn't wrong at all, and the filesize is actually reported incorrectly. Maybe there's some problem with his/her filesystem.
Incomplete downloads indeed don't have anything to do with NSIS. It's probably caused by a broken combination of webserver, internet provider and/or browser. He/she should try to download the file on another computer.
robert_inventor
7th October 2012 10:09 UTC
Yes he got that error message - and another time he got an access violation message, at OX0FB14818 (just in case something about that address means anything to anyone).
The curious thing is - that only my file is affected for him - and he is the only one of my users who has reported this issue - and that it is so nearly completed, just 7 KB of the file not downloaded (if it is a download issue). I tried mirrors on my website, same file with different file name and the same happens.
Also it happens when sending the file to him as an attachment by email as well - so in that case it's the google gmail servers, not my own website server, and still the same issue persists.
It's really curious - why should he get exactly the same issue by these different methods of sending the file to him?
Good idea to suggest he downloads to another computer can ask him if he has another computer to use in that way.
Does anyone have any other thoughts about this? Why just 7 KB smaller, and why it would make no difference sending it as an attachment, and why only my installer would be affected and none of the other programs he downloads and installs?
I do get users who report incomplete downloads, maybe a few times a year and the mirror file locations have been all that is needed to fix the issue. Can't even remember needing to send it as a file attachment. I get about 150 downloads a day so it is not like it is a seldom downloaded file.
It is a normal NSIS installer. I don't modify the installer in any way, just run the script from HM NSIS Edit - oh - and I sign it with ksign - don't know if that is anything to do with it? Then upload it.
I wonder if it could be anything to do with the digital certificates?... Perhaps if something was stripping the digital certificate that might make it smaller - though 7 KB seems rather large to be just the digital certificate - and can't imagine why anything would strip it??