[OpenJDK 2D-Dev] RFR: JDK-8263362: Avoid division by 0 in java/awt/font/TextJustifier.java justify

[Prasanta Sadhukhan]

On Wed, 10 Mar 2021 12:31:31 GMT, Matthias Baesken <mbaesken at openjdk.org> wrote:

> In java/awt/font/TextJustifier.java justify-method there is a potential code path where divison by zero might happen , see also the Sonar finding 
> https://sonarcloud.io/project/issues?id=shipilev_jdk&open=AXcqMwpm8sPJZZzONu1k&resolved=false&severities=CRITICAL&types=BUG
> 
> 
>             boolean hitLimit = (weight == 0) || (!lastPass && ((delta < 0) == (delta < gslimit)));
>             boolean absorbing = hitLimit && absorbweight > 0;
>             // predivide delta by weight
>             float weightedDelta = delta / weight; // not used if weight == 0
> 
> In case of (weight == 0) the division should not be done because the value of weightedDelta is unused in this case anyway.

src/java.desktop/share/classes/java/awt/font/TextJustifier.java line 159:

> 157:             // predivide delta by weight
> 158:             float weightedDelta = 0;
> 159:             if (weight != 0) { // not used if weight == 0

Can it ever be -ve? Maybe we can do weight > 0 check just as we do for absorbweight?

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PR: https://git.openjdk.java.net/jdk/pull/2912