RFR: 8290973: In AffineTransform, equals(Object) is inconsistent with hashCode()

[Martin Desruisseaux]

On Fri, 10 Jun 2022 09:39:48 GMT, Martin Desruisseaux <duke at openjdk.org> wrote:

> `AffineTransform.equals(Object)` and `hashCode()` break two contracts:
> 
> * `A.equals(A)` returns `false` if at least one affine transform coefficient is NaN.
> * `A.equals(B)` should imply `A.hashCode() == B.hashCode()`, but it is not the case if a coefficient is zero with an opposite sign in A and B.
> 
> This patch preserves the current behaviour regarding 0 (i.e. -0 is considered equal to +0) for backward compatibility reason. Instead the `hashCode()` method is updated for being consistent with `equals(Object)` behaviour.

src/java.desktop/share/classes/java/awt/geom/AffineTransform.java line 3916:

> 3914:     /**
> 3915:      * Returns a hash code for the given value, with negative zero
> 3916:      * collapsed into to the single positive zero.

Should I fix this trivial typo before the merge? ("into to" → "to").

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PR: https://git.openjdk.org/jdk/pull/9121