[jdk17] RFR: 6766844: ByteArrayInputStream#read with a byte array of length 0 not consistent with InputStream when at EOF [v2]

[Joe Wang]

On Fri, 2 Jul 2021 16:58:18 GMT, Brian Burkhalter <bpb at openjdk.org> wrote:

>> Modify the specification of `java.io.ByteArrayInputStream#read(byte[],int,int)` to indicate that `-1` is returned instead of `0` when the stream is at its end and the third parameter, `len`, is zero.
>
> Brian Burkhalter has updated the pull request incrementally with one additional commit since the last revision:
> 
>   6766844: Correct error messages in test

src/java.base/share/classes/java/io/ByteArrayInputStream.java line 161:

> 159:      * Unlike the {@link InputStream#read(byte[],int,int) overridden method}
> 160:      * of {@code InputStream}, this method returns {@code -1} instead of zero
> 161:      * if the end of the stream has been reached and {@code len == 0}.

The statement "return -1 if the end of the stream has been reached and len == 0" gives an impression that it requires both conditions to be met: end of the stream && len==0,  but the tests show -1 is expected if len == 0 without an attempt to read the stream. 

The overridden method stated that "If len is zero, then no bytes are read and 0 is returned", the above note looks like was meant for this statement since the overridden method also return -1 if the stream is at end of file.

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PR: https://git.openjdk.java.net/jdk17/pull/189