[OpenJDK 2D-Dev] RFR: 8263981: java.awt.image.ComponentSampleModel equals/hashcode use numBands twice

[Aleksey Shipilev]

On Mon, 22 Mar 2021 17:44:03 GMT, Sergey Bylokhov <serb at openjdk.org> wrote:

>> SonarCloud reports the problem in ComponentSampleModel.equals:
>>   Correct one of the identical sub-expressions on both sides of operator "&&"
>> 
>> ...near "this.numBands == that.numBands". It is checked twice. hashCode also processes it twice.
>
> src/java.desktop/share/classes/java/awt/image/ComponentSampleModel.java line 1228:
> 
>> 1226:         }
>> 1227:         hash ^= numBands;
>> 1228:         hash <<= 8;
> 
> Since this mistake was done in two places I think this is a typo here and not an intentional thing.

I am a bit confused by this comment :) I suspect that `equals` got duplicated `numBands` first, and then whoever did the `hashcode` just hashed the same fields in the same order, duplicating it again.

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PR: https://git.openjdk.java.net/jdk/pull/3125