Corrupt PNG on sprite - System Crash

[thomaswelton]

Compass Version 0.11.7
SASS Version 3.1.7
Mac OS X 10.7.3

It's possible for compass to cause a system wide crash if it attempts to create a sprite from corrupt png.

I was updating an existing sprite image by working in photoshop, I saved this file and put it in my sprite directory, edited some SCSS when compass watch kicked in and started eating up all of my computers resources.

It took me a while, and several computer restarts, to find out why my computer was being so slow until I managed to open my finder and delete the corrupt png at which point compass compile threw a file not found error when trying to create the sprite.

I reopened photoshop, re-saved the file and everything was fine. I'm not sure what was wrong with the image as it opened and displayed in Preview, but opening it in photoshop I got this error "Could not complete your request because the file-format module cannot parse the file."

The problem was reasonably difficult for a dev to spot before trying to create a sprite, and if the sprite generator kicks in a computer restart is required for it to become responsive again.

I still have the problematic png here http://thomas.clicklabs.co.uk/corrupt-png-compass-test.png

[ohrstrom]

Hi there

I just had the same experience - nearly systemwide crash when trying to compile a sass project with sprites.
If you take a look at your file - it is not a corrupted png, but a JPEG image with a .png extension... This causes the crash.
Actually it is rather a memory-leak than a system crash [Don't know much about this things, maybe i0m wrong].

With jpegs named as png cmpass/ruby eats up all memory. On my system [OS X 10.7.3] cpu usage was still low but it wanted to use several GBs of ram.

So finally this is not really a bug - as the problems are caused by the user :) But maybe it would be possible to avoid a freeze...

[thomaswelton]

This is a bug as Compass crashed my system, the user error did not cause the system crash, compass did.
If Compass can not build a sprite it should report an error in the same way it does if it can not compile a stylesheet (feature request maybe)

[ohrstrom]

Yes it should maybe not rely on the file extension to determine the image type.
About the 'caused by the user' - try to rename a dvd-image to readme.txt and open it with nano... this will also use all your memory.

[scottdavis]

this sounds like an issue with the png library and not compass... lets ping @wvanbergen

[wvanbergen]

This is not a problem in ChunkyPNG. The attached image is a JPEG, not a PNG image. Trying to read it with ChunkyPNG is raising an error, as expected:

> ChunkyPNG::Image.from_file 'jpeg_with_png_extension.png'
ChunkyPNG::SignatureMismatch: PNG signature not found!

My guess is the error handling in Compass may not handle this exception properly.

[scottdavis]

so ChunkyPNG::SignatureMismatch is an exception i can catch then?

[wvanbergen]

Yeah, or just ChunkyPNG::Exception to catch any problem that the PNG may have.

[scottdavis]

rather be specific in my catch so i can display a proper error message consider this on my list of things to get done.

[thomaswelton]

Thank you guys, much appreciated.

[gigafied]

This is still kind of an issue. Somehow (don't ask me how), a PSD file got saved as a PNG file and checked into the project. The PSD was smallish (33 KB), so it wasn't super obvious.

Anyway, basically when I tried to compile a sprite sheet, ruby ended up leaking a huge amount of memory, (in Activity Monitor, it showed over 13GB of actual used memory).

This is, of course, insane, there needs to be a better way of handling and catching something like this. The first time I tried it, the process just hung (terminal was in the background and I was doing something else), all of a sudden my comp just crashed. When I rebooted and tried to run it again, I noticed the hung process and opened Activity Monitor.

Took me a lot of trial and error to discover the issue and the PSD saved as a PNG. Ideally, Compass/ChunkyPNG would be able to spit some kind of warning/error out.

I'm not sure if this is a ChunkyPNG or Compass error however.

[pauloalem]

Today a jpeg saved as png filled up all of my memory in a matter of seconds. If there's any way I can help with this, please tell me.
I'm using compass (1.0.0.alpha.17), sass (3.3.0.rc.2) and the offending file is attached, but I guess any jpeg file with a different extension will do.

[jasonsemko]

Had this as well, could someone please add lines in verbose mode to explain what files compass is looking at as it moves through sprite generation?