RFR: 8155259: Suspicious buffer allocation in com.sun.tools.javac.file.BaseFileManager [v2]

[Archie L. Cobbs]

On Thu, 17 Nov 2022 19:11:14 GMT, Archie L. Cobbs <duke at openjdk.org> wrote:

>> JDK-8155259 notes that in `BaseFileManager` this code:
>> 
>> ByteBuffer.allocate(capacity + capacity>>1)
>> 
>> is actually equivalent (assuming no overflow) to:
>> 
>> ByteBuffer.allocate(capacity)
>> 
>> because in Java the `+` operator has higher precedence than the `>>` operator.
>> 
>> In the bug it is suggested that this be changed to reflect the presumed original intent to over-allocate by 50%, i.e.:
>> 
>> ByteBuffer.allocate(capacity + (capacity>>1))
>> 
>> however, this patch is more conservative in that it leaves the existing behavior alone and instead just simplifies it to:
>> 
>> ByteBuffer.allocate(capacity)
>> 
>> allowing us to at least resolve JDK-8155259.
>
> Archie L. Cobbs has updated the pull request with a new target base due to a merge or a rebase. The incremental webrev excludes the unrelated changes brought in by the merge/rebase. The pull request contains two additional commits since the last revision:
> 
>  - Merge branch 'master' into JDK-8155259
>  - 8155259: Suspicious buffer allocation in com.sun.tools.javac.file.BaseFileManager

keepalive

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PR: https://git.openjdk.org/jdk/pull/10803