ImageReaderSpi.canDecodeInput sometime throw EOFException

[Martin Desruisseaux]

Hello all

Invoking ImageReaderSpi.canDecodeInput(Object) with stream having less 
that 8 bytes causes an EOFException to be throw, while the expected 
behavior would be for the method to return false. This is caused by BMP, 
WBMP, GIF, PNG and TIFF reader implementations which assume that those 
bytes always exist and do not check EOF conditions. The JPEG reader is 
not impacted.

I have prepared a patch together with a test that reproduces the problem 
and verifies that the patch solves it. The changes in 
canDecodeInput(Object) method bodies are:

  * Use ImageInputStream.read() instead of readByte() and check for -1
    (EOF) return value.
  * Replace ImageInputStream.readFully(byte[]) calls by a private
    tryReadFully method.

The patch together with the tests are at [1]. Before to submit a pull 
request to JDK repository, if I remember correctly from my previous 
contribution I think that we need to fill a bug report on JIRA but it 
can not be done by myself. Can someone provides some guidance about the 
process and things that need to be changed in the proposed patch?

     Thanks,

         Martin

[1]https://github.com/Geomatys/jdk/commit/c996e83d5899b7ead0f8837aaea4cf991687a20e