Re: [OpenJDK 2D-Dev] [rfc]Stream doesn't reset mark in finally

[Jiri Vanek]

On 11/12/2015 02:24 PM, Sergey Bylokhov wrote:

Hi, Jiri.
This is a valid point, did you file a new CR for this issue?

Hello!

here it is:
https://jvanek.fedorapeople.org/oracle/jdk8/webrevs/resetInTryFinally/v1/

Patch:
https://jvanek.fedorapeople.org/oracle/jdk8/webrevs/resetInTryFinally/v1/webrev/
and reprodcuer
https://jvanek.fedorapeople.org/oracle/jdk8/webrevs/resetInTryFinally/v1/MarkTryFinallyReproducer.java


Reproducer can be easily turned to jtreg if wonted.

The patch is for 8, but is valid also for 9, except the path to file.
I will adapt it to 9 once you are ok with it (or you may on your own, depends 
on you)

J.

On 09.11.15 15:45, Alexander Scherbatiy wrote:

On 11/7/2015 11:38 AM, Jiri Vanek wrote:

Hello!

Looking to imageIO.java (if this is bad thread, please redirect me!)

     2d-dev alias should be also the right place to ask image related
questions in AWT.

    Thanks,
    Alexandr.

when reading images
http://hg.openjdk.java.net/jdk8/jdk8/jdk/file/687fd7c7986d/src/share/classes/javax/imageio/ImageIO.java#l543


and ending at:

                // Perform mark/reset as a defensive measure
                // even though plug-ins are supposed to take
                // care of it.
                boolean canDecode = false;
                if (stream != null) {
                    stream.mark();
                }
                canDecode = spi.canDecodeInput(input);
                if (stream != null) {
                    stream.reset();
                }
                return canDecode;

I'm wondering, why  stream.reset(); is not in finaly  block:

// Perform mark/reset as a defensive measure
// even though plug-ins are supposed to take
// care of it.
boolean canDecode = false;
if (stream != null) {
stream.mark();
}
try{
    canDecode = spi.canDecodeInput(input);
} finally {
    if (stream != null) {
        stream.reset();
    }
}
return canDecode;


Eg png and bmp decoders can are throwing IIOException when header is
corrutped. That pretty definitely sure killer of  stream mark stacks.
You yourselves write  : //Perform mark/reset as a defensive measure
even though plug-ins are supposed to take care of it.
So if densive, then try/finaly please.

I did not check if this changed in 9 but if not....Please. This is
makig work on custom image plugins, for image formats which just wraps
another bmp/png and are expecting corrupted headers preatty hards.


J.